This is an automated email from the ASF dual-hosted git repository.
sijie pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/bookkeeper.git
The following commit(s) were added to refs/heads/master by this push:
new 4615742 release 4.5.0: update website
4615742 is described below
commit 4615742cc3947e4794aa0afda668876fd01887b1
Author: Sijie Guo <si...@apache.org>
AuthorDate: Thu Aug 10 12:56:48 2017 -0700
release 4.5.0: update website
Descriptions of the changes in this PR:
under `site`, run `./scripts/release.sh`
what the script does:
- copy the `latest` to `4.5.0`.
- finalize the version
- update config yml
Author: Sijie Guo <si...@apache.org>
Reviewers: Matteo Merli <mme...@apache.org>
This closes #429 from sijie/update_website_for_4.5_release
---
site/_config.yml | 5 +-
site/docs/4.5.0/admin/autorecovery.md | 128 ++++++
site/docs/{latest => 4.5.0}/admin/bookies.md | 2 +-
site/docs/4.5.0/admin/geo-replication.md | 22 +
site/docs/{latest => 4.5.0}/admin/metrics.md | 2 +-
site/docs/4.5.0/admin/perf.md | 3 +
site/docs/4.5.0/admin/placement.md | 3 +
site/docs/4.5.0/admin/upgrade.md | 73 ++++
site/docs/4.5.0/api/distributedlog-api.md | 395 ++++++++++++++++++
site/docs/4.5.0/api/ledger-adv-api.md | 82 ++++
site/docs/4.5.0/api/ledger-api.md | 473 ++++++++++++++++++++++
site/docs/4.5.0/api/overview.md | 17 +
site/docs/4.5.0/deployment/dcos.md | 142 +++++++
site/docs/4.5.0/deployment/kubernetes.md | 4 +
site/docs/{latest => 4.5.0}/deployment/manual.md | 2 +-
site/docs/4.5.0/development/codebase.md | 3 +
site/docs/4.5.0/development/protocol.md | 148 +++++++
site/docs/4.5.0/example.md | 6 +
site/docs/4.5.0/getting-started/concepts.md | 202 +++++++++
site/docs/4.5.0/getting-started/installation.md | 74 ++++
site/docs/4.5.0/getting-started/run-locally.md | 16 +
site/docs/{latest => 4.5.0}/overview/overview.md | 6 +-
site/docs/4.5.0/overview/releaseNotes.md | 17 +
site/docs/4.5.0/overview/releaseNotesTemplate.md | 17 +
site/docs/4.5.0/reference/cli.md | 10 +
site/docs/{latest => 4.5.0}/reference/config.md | 2 +-
site/docs/4.5.0/reference/metrics.md | 3 +
site/docs/4.5.0/security/overview.md | 21 +
site/docs/4.5.0/security/sasl.md | 202 +++++++++
site/docs/4.5.0/security/tls.md | 210 ++++++++++
site/docs/4.5.0/security/zookeeper.md | 41 ++
site/docs/latest/admin/bookies.md | 2 +-
site/docs/latest/admin/metrics.md | 2 +-
site/docs/latest/deployment/manual.md | 2 +-
site/docs/latest/overview/overview.md | 2 +-
site/docs/latest/overview/releaseNotes.md | 2 +-
site/docs/latest/overview/releaseNotesTemplate.md | 2 +-
site/docs/latest/reference/config.md | 2 +-
site/releases.md | 4 +
39 files changed, 2333 insertions(+), 16 deletions(-)
diff --git a/site/_config.yml b/site/_config.yml
index 5b22804..5340755 100644
--- a/site/_config.yml
+++ b/site/_config.yml
@@ -10,6 +10,7 @@ twitter_url: https://twitter.com/asfbookkeeper
livereload: true
versions:
+- "4.5.0"
# [next_version_placehodler]
archived_versions:
@@ -24,8 +25,8 @@ archived_versions:
- "4.2.0"
- "4.1.0"
- "4.0.0"
-latest_version: "4.5.0-SNAPSHOT"
-latest_release: "4.4.0"
+latest_version: "4.6.0-SNAPSHOT"
+latest_release: "4.5.0"
stable_release: "4.4.0"
distributedlog_version: "2.1.0-0.4.0"
diff --git a/site/docs/4.5.0/admin/autorecovery.md
b/site/docs/4.5.0/admin/autorecovery.md
new file mode 100644
index 0000000..64c6beb
--- /dev/null
+++ b/site/docs/4.5.0/admin/autorecovery.md
@@ -0,0 +1,128 @@
+---
+title: Using AutoRecovery
+---
+
+When a {% pop bookie %} crashes, all {% pop ledgers %} on that bookie become
under-replicated. In order to bring all ledgers in your BookKeeper cluster back
to full replication, you'll need to *recover* the data from any offline
bookies. There are two ways to recover bookies' data:
+
+1. Using [manual recovery](#manual-recovery)
+1. Automatically, using [*AutoRecovery*](#autorecovery)
+
+## Manual recovery
+
+You can manually recover failed bookies using the
[`bookkeeper`](../../reference/cli) command-line tool. You need to specify:
+
+* that the `org.apache.bookkeeper.tools.BookKeeperTools` class needs to be run
+* an IP and port for your BookKeeper cluster's ZooKeeper ensemble
+* the IP and port for the failed bookie
+
+Here's an example:
+
+```bash
+$ bookkeeper-server/bin/bookkeeper org.apache.bookkeeper.tools.BookKeeperTools
\
+ zk1.example.com:2181 \ # IP and port for ZooKeeper
+ 192.168.1.10:3181 # IP and port for the failed bookie
+```
+
+If you wish, you can also specify which bookie you'd like to rereplicate to.
Here's an example:
+
+```bash
+$ bookkeeper-server/bin/bookkeeper org.apache.bookkeeper.tools.BookKeeperTools
\
+ zk1.example.com:2181 \ # IP and port for ZooKeeper
+ 192.168.1.10:3181 \ # IP and port for the failed bookie
+ 192.168.1.11:3181 # IP and port for the bookie to rereplicate to
+```
+
+### The manual recovery process
+
+When you initiate a manual recovery process, the following happens:
+
+1. The client (the process running ) reads the metadata of active ledgers from
ZooKeeper.
+1. The ledgers that contain segments from the failed bookie in their ensemble
are selected.
+1. A recovery process is initiated for each ledger in this list and the
rereplication process is run for each ledger.
+1. Once all the ledgers are marked as fully replicated, bookie recovery is
finished.
+
+## AutoRecovery
+
+AutoRecovery is a process that:
+
+* automatically detects when a {% pop bookie %} in your BookKeeper cluster has
become unavailable and then
+* rereplicates all the {% pop ledgers %} that were stored on that bookie.
+
+AutoRecovery can be run in two ways:
+
+1. On dedicated nodes in your BookKeeper cluster
+1. On the same machines on which your bookies are running
+
+## Running AutoRecovery
+
+You can start up AutoRecovery using the
[`autorecovery`](../../reference/cli#bookkeeper-autorecovery) command of the
[`bookkeeper`](../../reference/cli) CLI tool.
+
+```bash
+$ bookkeeper-server/bin/bookkeeper autorecovery
+```
+
+> The most important thing to ensure when starting up AutoRecovery is that the
ZooKeeper connection string specified by the
[`zkServers`](../../reference/config#zkServers) parameter points to the right
ZooKeeper cluster.
+
+If you start up AutoRecovery on a machine that is already running a bookie,
then the AutoRecovery process will run alongside the bookie on a separate
thread.
+
+You can also start up AutoRecovery on a fresh machine if you'd like to create
a dedicated cluster of AutoRecovery nodes.
+
+## Configuration
+
+There are a handful of AutoRecovery-related configs in the
[`bk_server.conf`](../../reference/config) configuration file. For a listing of
those configs, see [AutoRecovery
settings](../../reference/config#autorecovery-settings).
+
+## Disable AutoRecovery
+
+You can disable AutoRecovery at any time, for example during maintenance.
Disabling AutoRecovery ensures that bookies' data isn't unnecessarily
rereplicated when the bookie is only taken down for a short period of time, for
example when the bookie is being updated or the configuration if being changed.
+
+You can disable AutoRecover using the
[`bookkeeper`](../../reference/cli#bookkeeper-shell-autorecovery) CLI tool:
+
+```bash
+$ bookkeeper-server/bin/bookkeeper shell autorecovery -disable
+```
+
+Once disabled, you can reenable AutoRecovery using the
[`enable`](../../reference/cli#bookkeeper-shell-autorecovery) shell command:
+
+```bash
+$ bookkeeper-server/bin/bookkeeper shell autorecovery -enable
+```
+
+## AutoRecovery architecture
+
+AutoRecovery has two components:
+
+1. The [**auditor**](#auditor) (see the
[`Auditor`](../../api/javadoc/org/apache/bookkeeper/replication/Auditor.html)
class) is a singleton node that watches bookies to see if they fail and creates
rereplication tasks for the ledgers on failed bookies.
+1. The [**replication worker**](#replication-worker) (see the
[`ReplicationWorker`](../../api/javadoc/org/apache/bookkeeper/replication/ReplicationWorker.html)
class) runs on each bookie and executes rereplication tasks provided by the
auditor.
+
+Both of these components run as threads in the
[`AutoRecoveryMain`](../../api/javadoc/org/apache/bookkeeper/replication/AutoRecoveryMain)
process, which runs on each bookie in the cluster. All recovery nodes
participate in leader election---using ZooKeeper---to decide which node becomes
the auditor. Nodes that fail to become the auditor watch the elected auditor
and run an election process again if they see that the auditor node has failed.
+
+### Auditor
+
+The auditor watches all bookies in the cluster that are registered with
ZooKeeper. Bookies register with ZooKeeper at startup. If the bookie crashes or
is killed, the bookie's registration in ZooKeeper disappears and the auditor is
notified of the change in the list of registered bookies.
+
+When the auditor sees that a bookie has disappeared, it immediately scans the
complete {% pop ledger %} list to find ledgers that have data stored on the
failed bookie. Once it has a list of ledgers for that bookie, the auditor will
publish a rereplication task for each ledger under the `/underreplicated/`
[znode](https://zookeeper.apache.org/doc/current/zookeeperOver.html) in
ZooKeeper.
+
+### Replication Worker
+
+Each replication worker watches for tasks being published by the auditor on
the `/underreplicated/` znode in ZooKeeper. When a new task appears, the
replication worker will try to get a lock on it. If it cannot acquire the lock,
it will try the next entry. The locks are implemented using ZooKeeper ephemeral
znodes.
+
+The replication worker will scan through the rereplication task's ledger for
segments of which its local bookie is not a member. When it finds segments
matching this criterion, it will replicate the entries of that segment to the
local bookie. If, after this process, the ledger is fully replicated, the
ledgers entry under /underreplicated/ is deleted, and the lock is released. If
there is a problem replicating, or there are still segments in the ledger which
are still underreplicated (du [...]
+
+If the replication worker finds a segment which needs rereplication, but does
not have a defined endpoint (i.e. the final segment of a ledger currently being
written to), it will wait for a grace period before attempting rereplication.
If the segment needing rereplication still does not have a defined endpoint,
the ledger is fenced and rereplication then takes place.
+
+This avoids the situation in which a client is writing to a ledger and one of
the bookies goes down, but the client has not written an entry to that bookie
before rereplication takes place. The client could continue writing to the old
segment, even though the ensemble for the segment had changed. This could lead
to data loss. Fencing prevents this scenario from happening. In the normal
case, the client will try to write to the failed bookie within the grace
period, and will have started [...]
+
+You can configure this grace period using the
[`openLedgerRereplicationGracePeriod`](../../reference/config#openLedgerRereplicationGracePeriod)
parameter.
+
+### The rereplication process
+
+The ledger rereplication process happens in these steps:
+
+1. The client goes through all ledger segments in the ledger, selecting those
that contain the failed bookie.
+1. A recovery process is initiated for each ledger segment in this list.
+ 1. The client selects a bookie to which all entries in the ledger segment
will be replicated; In the case of autorecovery, this will always be the local
bookie.
+ 1. The client reads entries that belong to the ledger segment from other
bookies in the ensemble and writes them to the selected bookie.
+ 1. Once all entries have been replicated, the zookeeper metadata for the
segment is updated to reflect the new ensemble.
+ 1. The segment is marked as fully replicated in the recovery tool.
+1. Once all ledger segments are marked as fully replicated, the ledger is
marked as fully replicated.
+
diff --git a/site/docs/latest/admin/bookies.md
b/site/docs/4.5.0/admin/bookies.md
similarity index 99%
copy from site/docs/latest/admin/bookies.md
copy to site/docs/4.5.0/admin/bookies.md
index d9c6959..f9b1dcf 100644
--- a/site/docs/latest/admin/bookies.md
+++ b/site/docs/4.5.0/admin/bookies.md
@@ -177,4 +177,4 @@ If the change was the result of an accidental configuration
change, the change c
192.168.1.10:3181
```
- See the [AutoRecovery](../autorecovery) documentation for more info on the
re-replication process.
\ No newline at end of file
+ See the [AutoRecovery](../autorecovery) documentation for more info on the
re-replication process.
diff --git a/site/docs/4.5.0/admin/geo-replication.md
b/site/docs/4.5.0/admin/geo-replication.md
new file mode 100644
index 0000000..38b9723
--- /dev/null
+++ b/site/docs/4.5.0/admin/geo-replication.md
@@ -0,0 +1,22 @@
+---
+title: Geo-replication
+subtitle: Replicate data across BookKeeper clusters
+---
+
+*Geo-replication* is the replication of data across BookKeeper clusters. In
order to enable geo-replication for a group of BookKeeper clusters,
+
+## Global ZooKeeper
+
+Setting up a global ZooKeeper quorum is a lot like setting up a
cluster-specific quorum. The crucial difference is that
+
+### Geo-replication across three clusters
+
+Let's say that you want to set up geo-replication across clusters in regions
A, B, and C. First, the BookKeeper clusters in each region must have their own
local (cluster-specific) ZooKeeper quorum.
+
+> BookKeeper clusters use global ZooKeeper only for metadata storage. Traffic
from bookies to ZooKeeper should thus be fairly light in general.
+
+The crucial difference between using cluster-specific ZooKeeper and global
ZooKeeper is that {% pop bookies %} is that you need to point all bookies to
use the global ZooKeeper setup.
+
+## Region-aware placement polocy
+
+## Autorecovery
diff --git a/site/docs/latest/admin/metrics.md
b/site/docs/4.5.0/admin/metrics.md
similarity index 99%
copy from site/docs/latest/admin/metrics.md
copy to site/docs/4.5.0/admin/metrics.md
index e2595d6..635135f 100644
--- a/site/docs/latest/admin/metrics.md
+++ b/site/docs/4.5.0/admin/metrics.md
@@ -38,4 +38,4 @@ To enable stats:
<!-- ## Enabling stats in the bookkeeper library
TODO
--->
\ No newline at end of file
+-->
diff --git a/site/docs/4.5.0/admin/perf.md b/site/docs/4.5.0/admin/perf.md
new file mode 100644
index 0000000..8295632
--- /dev/null
+++ b/site/docs/4.5.0/admin/perf.md
@@ -0,0 +1,3 @@
+---
+title: Performance tuning
+---
diff --git a/site/docs/4.5.0/admin/placement.md
b/site/docs/4.5.0/admin/placement.md
new file mode 100644
index 0000000..ded456e
--- /dev/null
+++ b/site/docs/4.5.0/admin/placement.md
@@ -0,0 +1,3 @@
+---
+title: Customized placement policies
+---
diff --git a/site/docs/4.5.0/admin/upgrade.md b/site/docs/4.5.0/admin/upgrade.md
new file mode 100644
index 0000000..456df99
--- /dev/null
+++ b/site/docs/4.5.0/admin/upgrade.md
@@ -0,0 +1,73 @@
+---
+title: Upgrade
+---
+
+> If you have questions about upgrades (or need help), please feel free to
reach out to us by [mailing list]({{ site.baseurl }}community/mailing-lists) or
[Slack Channel]({{ site.baseurl }}community/slack).
+
+## Overview
+
+Consider the below guidelines in preparation for upgrading.
+
+- Always back up all your configuration files before upgrading.
+- Read through the documentation and draft an upgrade plan that matches your
specific requirements and environment before starting the upgrade process.
+ Put differently, don't start working through the guide on a live cluster.
Read guide entirely, make a plan, then execute the plan.
+- Pay careful consideration to the order in which components are upgraded. In
general, you need to upgrade bookies first and then upgrade your clients.
+- If autorecovery is running along with bookies, you need to pay attention to
the upgrade sequence.
+- Read the release notes carefully for each release. They contain not only
information about noteworthy features, but also changes to configurations
+ that may impact your upgrade.
+- Always upgrade one or a small set of bookies to canary new version before
upgraing all bookies in your cluster.
+
+## Canary
+
+It is wise to canary an upgraded version in one or small set of bookies before
upgrading all bookies in your live cluster.
+
+You can follow below steps on how to canary a upgraded version:
+
+1. Stop a Bookie.
+2. Upgrade the binary and configuration.
+3. Start the Bookie in `ReadOnly` mode. This can be used to verify if the
Bookie of this new version can run well for read workload.
+4. Once the Bookie is running at `ReadOnly` mode successfully for a while,
restart the Bookie in `Write/Read` mode.
+5. After step 4, the Bookie will serve both write and read traffic.
+
+### Rollback Canaries
+
+If problems occur during canarying an upgraded version, you can simply take
down the problematic Bookie node. The remain bookies in the old cluster
+will repair this problematic bookie node by autorecovery. Nothing needs to be
worried about.
+
+## Upgrade Steps
+
+Once you determined a version is safe to upgrade in a few nodes in your
cluster, you can perform following steps to upgrade all bookies in your cluster.
+
+1. Determine if autorecovery is running along with bookies. If yes, check if
the clients (either new clients with new binary or old clients with new
configurations)
+are allowed to talk to old bookies; if clients are not allowed to talk to old
bookies, please [disable autorecovery](../../reference/cli/#autorecovery-1)
during upgrade.
+2. Decide on performing a rolling upgrade or a downtime upgrade.
+3. Upgrade all Bookies (more below)
+4. If autorecovery was disabled during upgrade, [enable
autorecovery](../../reference/cli/#autorecovery-1).
+5. After all bookies are upgraded, build applications that use `BookKeeper
client` against the new bookkeeper libraries and deploy the new versions.
+
+### Upgrade Bookies
+
+In a rolling upgrade scenario, upgrade one Bookie at a time. In a downtime
upgrade scenario, take the entire cluster down, upgrade each Bookie, then start
the cluster.
+
+For each Bookie:
+
+1. Stop the bookie.
+2. Upgrade the software (either new binary or new configuration)
+2. Start the bookie.
+
+## Upgrade Guides
+
+We describes the general upgrade method in Apache BookKeeper as above. We will
cover the details for individual versions.
+
+### 4.4.x to 4.5.x upgrade
+
+There isn't any protocol related backward compabilities changes in 4.5.0. So
you can follow the general upgrade sequence to upgrade from 4.4.x to 4.5.x.
+However, we list a list of things that you might want to know.
+
+1. 4.5.x upgrades netty from 3.x to 4.x. The memory usage pattern might be
changed a bit. Netty 4 uses more direct memory. Please pay attention to your
memory usage
+ and adjust the JVM settings accordingly.
+2. `multi journals` is a non-rollbackable feature. If you configure a bookie
to use multiple journals on 4.5.x you can not roll the bookie back to use
4.4.x. You have
+ to take a bookie out and recover it if you want to rollback to 4.4.x.
+
+If you are planning to upgrade a non-secured cluster to a secured cluster
enabling security features in 4.5.0, please read [BookKeeper
Security](../../security/overview) for more details.
+
diff --git a/site/docs/4.5.0/api/distributedlog-api.md
b/site/docs/4.5.0/api/distributedlog-api.md
new file mode 100644
index 0000000..7bb4029
--- /dev/null
+++ b/site/docs/4.5.0/api/distributedlog-api.md
@@ -0,0 +1,395 @@
+---
+title: DistributedLog
+subtitle: A higher-level API for managing BookKeeper entries
+---
+
+> DistributedLog began its life as a separate project under the Apache
Foundation. It was merged into BookKeeper in 2017.
+
+The DistributedLog API is an easy-to-use interface for managing BookKeeper
entries that enables you to use BookKeeper without needing to interact with
[ledgers](../ledger-api) directly.
+
+DistributedLog (DL) maintains sequences of records in categories called *logs*
(aka *log streams*). *Writers* append records to DL logs, while *readers* fetch
and process those records.
+
+## Architecture
+
+The diagram below illustrates how the DistributedLog API works with BookKeeper:
+
+
+
+## Logs
+
+A *log* in DistributedLog is an ordered, immutable sequence of *log records*.
+
+The diagram below illustrates the anatomy of a log stream:
+
+
+
+### Log records
+
+Each log record is a sequence of bytes. Applications are responsible for
serializing and deserializing byte sequences stored in log records.
+
+Log records are written sequentially into a *log stream* and assigned with a a
unique sequence number called a DLSN
(<strong>D</strong>istributed<strong>L</strong>og <strong>S</strong>equence
<strong>N</strong>umber).
+
+In addition to a DLSN, applications can assign their own sequence number when
constructing log records. Application-defined sequence numbers are known as
*TransactionIDs* (or *txid*). Either a DLSN or a TransactionID can be used for
positioning readers to start reading from a specific log record.
+
+### Log segments
+
+Each log is broken down into *log segments* that contain subsets of records.
Log segments are distributed and stored in BookKeeper. DistributedLog rolls the
log segments based on the configured *rolling policy*, which be either
+
+* a configurable period of time (such as every 2 hours), or
+* a configurable maximum size (such as every 128 MB).
+
+The data in logs is divided up into equally sized log segments and distributed
evenly across {% pop bookies %}. This allows logs to scale beyond a size that
would fit on a single server and spreads read traffic across the cluster.
+
+### Namespaces
+
+Log streams that belong to the same organization are typically categorized and
managed under a *namespace*. DistributedLog namespaces essentially enable
applications to locate log streams. Applications can perform the following
actions under a namespace:
+
+* create streams
+* delete streams
+* truncate streams to a given sequence number (either a DLSN or a
TransactionID)
+
+## Writers
+
+Through the DistributedLog API, writers write data into logs of their choice.
All records are appended into logs in order. The sequencing is performed by the
writer, which means that there is only one active writer for a log at any given
time.
+
+DistributedLog guarantees correctness when two writers attempt to write to the
same log when a network partition occurs using a *fencing* mechanism in the log
segment store.
+
+### Write Proxy
+
+Log writers are served and managed in a service tier called the *Write Proxy*
(see the diagram [above](#architecture)). The Write Proxy is used for accepting
writes from a large number of clients.
+
+## Readers
+
+DistributedLog readers read records from logs of their choice, starting with a
provided position. The provided position can be either a DLSN or a
TransactionID.
+
+Readers read records from logs in strict order. Different readers can read
records from different positions in the same log.
+
+Unlike other pub-sub systems, DistributedLog doesn't record or manage readers'
positions. This means that tracking is the responsibility of applications, as
different applications may have different requirements for tracking and
coordinating positions. This is hard to get right with a single approach.
Distributed databases, for example, might store reader positions along with
SSTables, so they would resume applying transactions from the positions store
in SSTables. Tracking reader positi [...]
+
+### Read Proxy
+
+Log records can be cached in a service tier called the *Read Proxy* to serve a
large number of readers. See the diagram [above](#architecture). The Read Proxy
is the analogue of the [Write Proxy](#write-proxy).
+
+## Guarantees
+
+The DistributedLog API for BookKeeper provides a number of guarantees for
applications:
+
+* Records written by a [writer](#writers) to a [log](#logs) are appended in
the order in which they are written. If a record **R1** is written by the same
writer as a record **R2**, **R1** will have a smaller sequence number than
**R2**.
+* [Readers](#readers) see [records](#log-records) in the same order in which
they are [written](#writers) to the log.
+* All records are persisted on disk by BookKeeper before acknowledgements,
which guarantees durability.
+* For a log with a replication factor of N, DistributedLog tolerates up to N-1
server failures without losing any records.
+
+## API
+
+Documentation for the DistributedLog API can be found
[here](https://distributedlog.incubator.apache.org/docs/latest/user_guide/api/core).
+
+> At a later date, the DistributedLog API docs will be added here.
+
+<!--
+
+The DistributedLog core library is written in Java and interacts with
namespaces and logs directly.
+
+### Installation
+
+The BookKeeper Java client library is available via [Maven
Central](http://search.maven.org/) and can be installed using [Maven](#maven),
[Gradle](#gradle), and other build tools.
+
+### Maven
+
+If you're using [Maven](https://maven.apache.org/), add this to your
[`pom.xml`](https://maven.apache.org/guides/introduction/introduction-to-the-pom.html)
build configuration file:
+
+```xml
+<-- in your <properties> block ->
+<bookkeeper.version>{{ site.distributedlog_version }}</bookkeeper.version>
+
+<-- in your <dependencies> block ->
+<dependency>
+ <groupId>org.apache.bookkeeper</groupId>
+ <artifactId>bookkeeper-server</artifactId>
+ <version>${bookkeeper.version}</version>
+</dependency>
+```
+
+### Gradle
+
+If you're using [Gradle](https://gradle.org/), add this to your
[`build.gradle`](https://spring.io/guides/gs/gradle/) build configuration file:
+
+```groovy
+dependencies {
+ compile group: 'org.apache.bookkeeper', name: 'bookkeeper-server',
version: '4.5.0'
+}
+
+// Alternatively:
+dependencies {
+ compile 'org.apache.bookkeeper:bookkeeper-server:4.5.0'
+}
+```
+
+### Namespace API
+
+A DL [namespace](#namespace) is a collection of [log streams](#log-streams).
When using the DistributedLog API with BookKeeper, you need to provide your
Java client with a namespace URI. That URI consists of three elements:
+
+1. The `distributedlog-bk` scheme
+1. A connection string for your BookKeeper cluster. You have three options for
the connection string:
+ * An entire ZooKeeper connection string, for example
`zk1:2181,zk2:2181,zk3:2181`
+ * A host and port for one node in your ZooKeeper cluster, for example
`zk1:2181`. In general, it's better to provide a full ZooKeeper connection
string.
+ * If your ZooKeeper cluster can be discovered via DNS, you can provide the
DNS name, for example `my-zookeeper-cluster.com`.
+1. A path that points to the location where logs are stored. This could be a
ZooKeeper [znode](https://zookeeper.apache.org/doc/current/zookeeperOver.html).
+
+This is the general structure of a namespace URI:
+
+```shell
+distributedlog-bk://{connection-string}/{path}
+```
+
+Here are some example URIs:
+
+```shell
+distributedlog-bk://zk1:2181,zk2:2181,zk3:2181/my-namespace # Full ZooKeeper
connection string
+distributedlog-bk://localhost:2181/my-namespace # Single ZooKeeper
node
+distributedlog-bk://my-zookeeper-cluster.com/my-namespace # DNS name for
ZooKeeper
+```
+
+#### Creating namespaces
+
+In order to create namespaces, you need to use the command-line tool.
+
+```shell
+$
+```
+
+#### Using namespaces
+
+Once you have a namespace URI, you can build a namespace instance, which will
be used for operating streams. Use the `DistributedLogNamespaceBuilder` to
build a `DistributedLogNamespace` object, passing in a
`DistributedLogConfiguration`, a URI, and optionally a stats logger and a
feature provider.
+
+```java
+DistributedLogConfiguration conf = new DistributedLogConfiguration();
+URI uri = URI.create("distributedlog-bk://localhost:2181/my-namespace ");
+DistributedLogNamespaceBuilder builder =
DistributedLogNamespaceBuilder.newBuilder();
+DistributedLogNamespace = builder
+ .conf(conf) // Configuration for the namespace
+ .uri(uri) // URI for the namespace
+ .statsLogger(...) // Stats logger for statistics
+ .featureProvider(...) // Feature provider for controlling features
+ .build();
+```
+
+### Log API
+
+#### Creating logs
+
+You can create a log by calling the `createLog` method on a
`DistributedLogNamespace` object, passing in a name for the log. This creates
the log under the namespace but does *not* return a handle for operating the
log.
+
+```java
+DistributedLogNamespace namespace = /* Create namespace */;
+try {
+ namespace.createLog("test-log");
+} catch (IOException e) }
+ // Handle the log creation exception
+}
+```
+
+#### Opening logs
+
+A `DistributedLogManager` handle will be returned when opening a log using the
`openLog` function, which takes the name of the log. This handle can be used
for writing records to or reading records from the log.
+
+> If the log doesn't exist and `createStreamIfNotExists` is set to `true` in
the configuration, the log will be created automatically when writing the first
record.
+
+```java
+DistributedLogConfiguration conf = new DistributedLogConfiguration();
+conf.setCreateStreamIfNotExists(true);
+DistributedLogNamespace namespace = DistributedLogNamespace.newBuilder()
+ .conf(conf)
+ // Other builder attributes
+ .build();
+DistributedLogManager logManager = namespace.openLog("test-log");
+```
+
+Sometimes, applications may open a log with a different configuration from the
enclosing namespace. This can be done using the same `openLog` method:
+
+```java
+// Namespace configuration
+DistributedLogConfiguration namespaceConf = new DistributedLogConfiguration();
+conf.setRetentionPeriodHours(24);
+URI uri = URI.create("distributedlog-bk://localhost:2181/my-namespace");
+DistributedLogNamespace namespace = DistributedLogNamespace.newBuilder()
+ .conf(namespaceConf)
+ .uri(uri)
+ // Other builder attributes
+ .build();
+// Log-specific configuration
+DistributedLogConfiguration logConf = new DistributedLogConfiguration();
+logConf.setRetentionPeriodHours(12);
+DistributedLogManager logManager = namespace.openLog(
+ "test-log",
+ Optional.of(logConf),
+ Optional.absent()
+);
+```
+
+#### Deleting logs
+
+The `DistributedLogNamespace` class provides `deleteLog` function that can be
used to delete logs. When you delete a lot, the client library will attempt to
acquire a lock on the log before deletion. If the log is being written to by an
active writer, deletion will fail (as the other writer currently holds the
lock).
+
+```java
+try {
+ namespace.deleteLog("test-log");
+} catch (IOException e) {
+ // Handle exception
+}
+```
+
+#### Checking for the existence of a log
+
+Applications can check whether a log exists by calling the `logExists`
function.
+
+```java
+if (namespace.logExists("test-log")) {
+ // Perform some action when the log exists
+} else {
+ // Perform some action when the log doesn't exist
+}
+```
+
+#### Listing logs
+
+Applications can retrieve a list of all logs under a namespace using the
`getLogs` function.
+
+```java
+Iterator<String> logs = namespace.getLogs();
+while (logs.hasNext()) {
+ String logName = logs.next();
+ // Do something with the log name, such as print
+}
+```
+
+### Writer API
+
+You can write to DistributedLog logs either
[synchronously](#writing-to-logs-synchronously) using the `LogWriter` class or
[asynchronously](#writing-to-logs-asynchronously) using the `AsyncLogWriter`
class.
+
+#### Immediate flush
+
+By default, records are buffered rather than being written immediately. You
can disable this behavior and make DL writers write ("flush") entries
immediately by adding the following to your configuration object:
+
+```java
+conf.setImmediateFlushEnabled(true);
+conf.setOutputBufferSize(0);
+conf.setPeriodicFlushFrequencyMilliSeconds(0);
+```
+
+#### Immediate locking
+
+By default, DL writers can write to a log stream when other writers are also
writing to that stream. You can override this behavior and disable other
writers from writing to the stream by adding this to your configuration:
+
+```java
+conf.setLockTimeout(DistributedLogConstants.LOCK_IMMEDIATE);
+```
+
+#### Writing to logs synchronously
+
+To write records to a log synchronously, you need to instantiate a `LogWriter`
object using a `DistributedLogManager`. Here's an example:
+
+```java
+DistributedLogNamespace namespace = /* Some namespace object */;
+DistributedLogManager logManager = namespace.openLog("test-log");
+LogWriter writer = logManager.startLogSegmentNonPartitioned();
+```
+
+> The DistributedLog library enforces single-writer semantics by deploying a
ZooKeeper locking mechanism. If there is only one active writer, subsequent
calls to `startLogSegmentNonPartitioned` will fail with an
`OwnershipAcquireFailedException`.
+
+Log records represent the data written to a log stream. Each log record is
associated with an application-defined [TransactionID](#log-records). This ID
must be non decreasing or else writing a record will be rejected with
`TransactionIdOutOfOrderException`. The application is allowed to bypass the
TransactionID sanity checking by setting `maxIdSanityCheck` to `false` in the
configuration. System time and atomic numbers are good candidates for
TransactionID.
+
+```java
+long txid = 1L;
+byte[] data = "some byte array".getBytes();
+LogRecord record = new LogRecord(txid, data);
+```
+
+Your application can write either a single record, using the `write` method,
or many records, using the `writeBulk` method.
+
+```java
+// Single record
+writer.write(record);
+
+// Bulk write
+List<LogRecord> records = Lists.newArrayList();
+records.add(record);
+writer.writeBulk(records);
+```
+
+The write calls return immediately after the records are added into the output
buffer of writer. This means that the data isn't guaranteed to be durable until
the writer explicitly calls `setReadyToFlush` and `flushAndSync`. Those two
calls will first transmit buffered data to the backend, wait for transmit
acknowledgements (acks), and commit the written data to make them visible to
readers.
+
+```java
+// Flush the records
+writer.setReadyToFlush();
+
+// Commit the records to make them visible to readers
+writer.flushAndSync();
+```
+
+Log streams in DistributedLog are endless streams *unless they are sealed*.
Endless in this case means that writers can keep writing records to those
streams, readers can keep reading from the end of those streams, and the
process never stops. Your application can seal a log stream using the
`markEndOfStream` method:
+
+```java
+writer.markEndOfStream();
+```
+
+#### Writing to logs asynchronously
+
+In order to write to DistributedLog logs asynchronously, you need to create an
`AsyncLogWriter` instread of a `LogWriter`.
+
+```java
+DistributedLogNamespace namespace = /* Some namespace object */;
+DistributedLogManager logManager = namespace.openLog("test-async-log");
+AsyncLogWriter asyncWriter = logManager.startAsyncLogSegmentNonPartitioned();
+```
+
+All writes to `AsyncLogWriter` are non partitioned. The futures representing
write results are only satisfied when the data is durably persisted in the
stream. A [DLSN](#log-records) will be returned for each write, which is used
to represent the position (aka offset) of the record in the log stream. All the
records added in order are guaranteed to be persisted in order. Here's an
example of an async writer that gathers a list of futures representing multiple
async write results:
+
+```java
+List<Future<DLSN>> addFutures = Lists.newArrayList();
+for (long txid = 1L; txid <= 100L; txid++) {
+ byte[] data = /* some byte array */;
+ LogRecord record = new LogRecord(txid, data);
+ addFutures.add(asyncWriter.write(record));
+}
+List<DLSN> addResults = Await.result(Future.collect(addFutures));
+```
+
+The `AsyncLogWriter` also provides a method for truncating a stream to a given
DLSN. This is useful for building replicated state machines that need explicit
controls on when the data can be deleted.
+
+```java
+DLSN truncateDLSN = /* some DLSN */;
+Future<DLSN> truncateFuture = asyncWriter.truncate(truncateDLSN);
+
+// Wait for truncation result
+Await.result(truncateFuture);
+```
+
+##### Register a listener
+
+Instead of returning a future from write operations, you can also set up a
listener that performs assigned actions upon success or failure of the write.
Here's an example:
+
+```java
+asyncWriter.addEventListener(new FutureEventListener<DLSN>() {
+ @Override
+ public void onFailure(Throwable cause) {
+ // Execute if the attempt fails
+ }
+
+ @Override
+ public void onSuccess(DLSN value) {
+ // Execute if the attempt succeeds
+ }
+});
+```
+
+##### Close the writer
+
+You can close an async writer when you're finished with it like this:
+
+```java
+FutureUtils.result(asyncWriter.asyncClose());
+```
+
+<!--
+TODO: Reader API
+-->
diff --git a/site/docs/4.5.0/api/ledger-adv-api.md
b/site/docs/4.5.0/api/ledger-adv-api.md
new file mode 100644
index 0000000..f46950d
--- /dev/null
+++ b/site/docs/4.5.0/api/ledger-adv-api.md
@@ -0,0 +1,82 @@
+---
+title: The Advanced Ledger API
+---
+
+In release `4.5.0`, Apache BookKeeper introduces a few advanced API for
advanced usage.
+This sections covers these advanced APIs.
+
+> Before learn the advanced API, please read [Ledger API](../ledger-api) first.
+
+## LedgerHandleAdv
+
+[`LedgerHandleAdv`](../javadoc/org/apache/bookkeeper/client/LedgerHandleAdv)
is an advanced extension of
[`LedgerHandle`](../javadoc/org/apache/bookkeeper/client/LedgerHandle).
+It allows user passing in an `entryId` when adding an entry.
+
+### Creating advanced ledgers
+
+Here's an exmaple:
+
+```java
+byte[] passwd = "some-passwd".getBytes();
+LedgerHandleAdv handle = bkClient.createLedgerAdv(
+ 3, 3, 2, // replica settings
+ DigestType.CRC32,
+ passwd);
+```
+
+You can also create advanced ledgers asynchronously.
+
+```java
+class LedgerCreationCallback implements AsyncCallback.CreateCallback {
+ public void createComplete(int returnCode, LedgerHandle handle, Object
ctx) {
+ System.out.println("Ledger successfully created");
+ }
+}
+client.asyncCreateLedgerAdv(
+ 3, // ensemble size
+ 3, // write quorum size
+ 2, // ack quorum size
+ BookKeeper.DigestType.CRC32,
+ password,
+ new LedgerCreationCallback(),
+ "some context"
+);
+```
+
+Besides the APIs above, BookKeeper allows users providing `ledger-id` when
creating advanced ledgers.
+
+```java
+long ledgerId = ...; // the ledger id is generated externally.
+
+byte[] passwd = "some-passwd".getBytes();
+LedgerHandleAdv handle = bkClient.createLedgerAdv(
+ ledgerId, // ledger id generated externally
+ 3, 3, 2, // replica settings
+ DigestType.CRC32,
+ passwd);
+```
+
+> Please note, it is users' responsibility to provide a unique ledger id when
using the API above.
+> If a ledger already exists when users try to create an advanced ledger with
same ledger id,
+> a
[LedgerExistsException](../javadoc/org/apache/bookkeeper/client/BKException.BKLedgerExistException.html)
is thrown by the bookkeeper client.
+
+### Add Entries
+
+The normal [add entries api](ledger-api/#adding-entries-to-ledgers) in
advanced ledgers are disabled. Instead, when users want to add entries
+to advanced ledgers, an entry id is required to pass in along with the entry
data when adding an entry.
+
+```java
+long entryId = ...; // entry id generated externally
+
+ledger.addEntry(entryId, "Some entry data".getBytes());
+```
+
+A few notes when using this API:
+
+- The entry id has to be non-negative.
+- Clients are okay to add entries out of order.
+- However, the entries are only acknowledged in a monotonic order starting
from 0.
+
+### Read Entries
+
+The read entries api in advanced ledgers remain same as [normal
ledgers](../ledger-api/#reading-entries-from-ledgers).
diff --git a/site/docs/4.5.0/api/ledger-api.md
b/site/docs/4.5.0/api/ledger-api.md
new file mode 100644
index 0000000..4e1070d
--- /dev/null
+++ b/site/docs/4.5.0/api/ledger-api.md
@@ -0,0 +1,473 @@
+---
+title: The Ledger API
+---
+
+The ledger API is a lower-level API for BookKeeper that enables you to
interact with {% pop ledgers %} directly.
+
+## The Java ledger API client
+
+To get started with the Java client for BookKeeper, install the
`bookkeeper-server` library as a dependency in your Java application.
+
+> For a more in-depth tutorial that involves a real use case for BookKeeper,
see the [Example application](../example-application) guide.
+
+## Installation
+
+The BookKeeper Java client library is available via [Maven
Central](http://search.maven.org/) and can be installed using [Maven](#maven),
[Gradle](#gradle), and other build tools.
+
+### Maven
+
+If you're using [Maven](https://maven.apache.org/), add this to your
[`pom.xml`](https://maven.apache.org/guides/introduction/introduction-to-the-pom.html)
build configuration file:
+
+```xml
+<!-- in your <properties> block -->
+<bookkeeper.version>4.5.0</bookkeeper.version>
+
+<!-- in your <dependencies> block -->
+<dependency>
+ <groupId>org.apache.bookkeeper</groupId>
+ <artifactId>bookkeeper-server</artifactId>
+ <version>${bookkeeper.version}</version>
+</dependency>
+```
+
+### Gradle
+
+If you're using [Gradle](https://gradle.org/), add this to your
[`build.gradle`](https://spring.io/guides/gs/gradle/) build configuration file:
+
+```groovy
+dependencies {
+ compile group: 'org.apache.bookkeeper', name: 'bookkeeper-server',
version: '4.5.0'
+}
+
+// Alternatively:
+dependencies {
+ compile 'org.apache.bookkeeper:bookkeeper-server:4.5.0'
+}
+```
+
+## Connection string
+
+When interacting with BookKeeper using the Java client, you need to provide
your client with a connection string, for which you have three options:
+
+* Provide your entire ZooKeeper connection string, for example
`zk1:2181,zk2:2181,zk3:2181`.
+* Provide a host and port for one node in your ZooKeeper cluster, for example
`zk1:2181`. In general, it's better to provide a full connection string (in
case the ZooKeeper node you attempt to connect to is down).
+* If your ZooKeeper cluster can be discovered via DNS, you can provide the DNS
name, for example `my-zookeeper-cluster.com`.
+
+## Creating a new client
+
+In order to create a new
[`BookKeeper`](../javadoc/org/apache/bookkeeper/client/BookKeeper) client
object, you need to pass in a [connection string](#connection-string). Here is
an example client object using a ZooKeeper connection string:
+
+```java
+try {
+ String connectionString = "127.0.0.1:2181"; // For a single-node, local
ZooKeeper cluster
+ BookKeeper bkClient = new BookKeeper(connectionString);
+} catch (InterruptedException | IOException | KeeperException e) {
+ e.printStackTrace();
+}
+```
+
+> If you're running BookKeeper [locally](../../getting-started/run-locally),
using the [`localbookie`](../../reference/cli#bookkeeper-localbookie) command,
use `"127.0.0.1:2181"` for your connection string, as in the example above.
+
+There are, however, other ways that you can create a client object:
+
+* By passing in a
[`ClientConfiguration`](../javadoc/org/apache/bookkeeper/conf/ClientConfiguration)
object. Here's an example:
+
+ ```java
+ ClientConfiguration config = new ClientConfiguration();
+ config.setZkServers(zkConnectionString);
+ config.setAddEntryTimeout(2000);
+ BookKeeper bkClient = new BookKeeper(config);
+ ```
+
+* By specifying a `ClientConfiguration` and a
[`ZooKeeper`](http://zookeeper.apache.org/doc/current/api/org/apache/zookeeper/ZooKeeper.html)
client object:
+
+ ```java
+ ClientConfiguration config = new ClientConfiguration();
+ config.setAddEntryTimeout(5000);
+ ZooKeeper zkClient = new ZooKeeper(/* client args */);
+ BookKeeper bkClient = new BookKeeper(config, zkClient);
+ ```
+
+* Using the `forConfig` method:
+
+ ```java
+ BookKeeper bkClient = BookKeeper.forConfig(conf).build();
+ ```
+
+## Creating ledgers
+
+The easiest way to create a {% pop ledger %} using the Java client is via the
`createLedger` method, which creates a new ledger synchronously and returns a
[`LedgerHandle`](../javadoc/org/apache/bookkeeper/client/LedgerHandle). You
must specify at least a
[`DigestType`](../javadoc/org/apache/bookkeeper/client/BookKeeper.DigestType)
and a password.
+
+Here's an example:
+
+```java
+byte[] password = "some-password".getBytes();
+LedgerHandle handle = bkClient.createLedger(BookKeeper.DigestType.MAC,
password);
+```
+
+You can also create ledgers asynchronously
+
+### Create ledgers asynchronously
+
+```java
+class LedgerCreationCallback implements AsyncCallback.CreateCallback {
+ public void createComplete(int returnCode, LedgerHandle handle, Object
ctx) {
+ System.out.println("Ledger successfully created");
+ }
+}
+
+client.asyncCreateLedger(
+ 3,
+ 2,
+ BookKeeper.DigestType.MAC,
+ password,
+ new LedgerCreationCallback(),
+ "some context"
+);
+```
+
+## Adding entries to ledgers
+
+```java
+long entryId = ledger.addEntry("Some entry data".getBytes());
+```
+
+### Add entries asynchronously
+
+## Reading entries from ledgers
+
+```java
+Enumerator<LedgerEntry> entries = handle.readEntries(1, 99);
+```
+
+To read all possible entries from the ledger:
+
+```java
+Enumerator<LedgerEntry> entries =
+ handle.readEntries(0, handle.getLastAddConfirmed());
+
+while (entries.hasNextElement()) {
+ LedgerEntry entry = entries.nextElement();
+ System.out.println("Successfully read entry " + entry.getId());
+}
+```
+
+### Reading entries after the LastAddConfirmed range
+
+`readUnconfirmedEntries` allowing to read after the LastAddConfirmed range.
+It lets the client read without checking the local value of LastAddConfirmed,
so that it is possible to read entries for which the writer has not received
the acknowledge yet
+For entries which are within the range 0..LastAddConfirmed BookKeeper
guarantees that the writer has successfully received the acknowledge.
+For entries outside that range it is possible that the writer never received
the acknowledge and so there is the risk that the reader is seeing entries
before the writer and this could result in a consistency issue in some cases.
+With this method you can even read entries before the LastAddConfirmed and
entries after it with one call, the expected consistency will be as described
above.
+
+```java
+Enumerator<LedgerEntry> entries =
+ handle.readUnconfirmedEntries(0, lastEntryIdExpectedToRead);
+
+while (entries.hasNextElement()) {
+ LedgerEntry entry = entries.nextElement();
+ System.out.println("Successfully read entry " + entry.getId());
+}
+```
+
+## Deleting ledgers
+
+{% pop Ledgers %} can also be deleted synchronously or asynchronously.
+
+```java
+long ledgerId = 1234;
+
+try {
+ bkClient.deleteLedger(ledgerId);
+} catch (Exception e) {
+ e.printStackTrace();
+}
+```
+
+### Delete entries asynchronously
+
+Exceptions thrown:
+
+*
+
+```java
+class DeleteEntryCallback implements AsyncCallback.DeleteCallback {
+ public void deleteComplete() {
+ System.out.println("Delete completed");
+ }
+}
+```
+
+## Simple example
+
+> For a more involved BookKeeper client example, see the [example
application](#example-application) below.
+
+In the code sample below, a BookKeeper client:
+
+* creates a ledger
+* writes entries to the ledger
+* closes the ledger (meaning no further writes are possible)
+* re-opens the ledger for reading
+* reads all available entries
+
+```java
+// Create a client object for the local ensemble. This
+// operation throws multiple exceptions, so make sure to
+// use a try/catch block when instantiating client objects.
+BookKeeper bkc = new BookKeeper("localhost:2181");
+
+// A password for the new ledger
+byte[] ledgerPassword = /* some sequence of bytes, perhaps random */;
+
+// Create a new ledger and fetch its identifier
+LedgerHandle lh = bkc.createLedger(BookKeeper.DigestType.MAC, ledgerPassword);
+long ledgerId = lh.getId();
+
+// Create a buffer for four-byte entries
+ByteBuffer entry = ByteBuffer.allocate(4);
+
+int numberOfEntries = 100;
+
+// Add entries to the ledger, then close it
+for (int i = 0; i < numberOfEntries; i++){
+ entry.putInt(i);
+ entry.position(0);
+ lh.addEntry(entry.array());
+}
+lh.close();
+
+// Open the ledger for reading
+lh = bkc.openLedger(ledgerId, BookKeeper.DigestType.MAC, ledgerPassword);
+
+// Read all available entries
+Enumeration<LedgerEntry> entries = lh.readEntries(0, numberOfEntries - 1);
+
+while(entries.hasMoreElements()) {
+ ByteBuffer result = ByteBuffer.wrap(ls.nextElement().getEntry());
+ Integer retrEntry = result.getInt();
+
+ // Print the integer stored in each entry
+ System.out.println(String.format("Result: %s", retrEntry));
+}
+
+// Close the ledger and the client
+lh.close();
+bkc.close();
+```
+
+Running this should return this output:
+
+```shell
+Result: 0
+Result: 1
+Result: 2
+# etc
+```
+
+## Example application
+
+This tutorial walks you through building an example application that uses
BookKeeper as the replicated log. The application uses the [BookKeeper Java
client](../java-client) to interact with BookKeeper.
+
+> The code for this tutorial can be found in [this GitHub
repo](https://github.com/ivankelly/bookkeeper-tutorial/). The final code for
the `Dice` class can be found
[here](https://github.com/ivankelly/bookkeeper-tutorial/blob/master/src/main/java/org/apache/bookkeeper/Dice.java).
+
+### Setup
+
+Before you start, you will need to have a BookKeeper cluster running locally
on your machine. For installation instructions, see
[Installation](../../getting-started/installation).
+
+To start up a cluster consisting of six {% pop bookies %} locally:
+
+```shell
+$ bookkeeper-server/bin/bookkeeper localbookie 6
+```
+
+You can specify a different number of bookies if you'd like.
+
+### Goal
+
+The goal of the dice application is to have
+
+* multiple instances of this application,
+* possibly running on different machines,
+* all of which display the exact same sequence of numbers.
+
+In other words, the log needs to be both durable and consistent, regardless of
how many {% pop bookies %} are participating in the BookKeeper ensemble. If one
of the bookies crashes or becomes unable to communicate with the other bookies
in any way, it should *still* display the same sequence of numbers as the
others. This tutorial will show you how to achieve this.
+
+To begin, download the base application, compile and run it.
+
+```shell
+$ git clone https://github.com/ivankelly/bookkeeper-tutorial.git
+$ mvn package
+$ mvn exec:java -Dexec.mainClass=org.apache.bookkeeper.Dice
+```
+
+That should yield output that looks something like this:
+
+```
+[INFO] Scanning for projects...
+[INFO]
+[INFO] ------------------------------------------------------------------------
+[INFO] Building tutorial 1.0-SNAPSHOT
+[INFO] ------------------------------------------------------------------------
+[INFO]
+[INFO] --- exec-maven-plugin:1.3.2:java (default-cli) @ tutorial ---
+[WARNING] Warning: killAfter is now deprecated. Do you need it ? Please
comment on MEXEC-6.
+Value = 4
+Value = 5
+Value = 3
+```
+
+### The base application
+
+The application in this tutorial is a dice application. The `Dice` class below
has a `playDice` function that generates a random number between 1 and 6 every
second, prints the value of the dice roll, and runs indefinitely.
+
+```java
+public class Dice {
+ Random r = new Random();
+
+ void playDice() throws InterruptedException {
+ while (true) {
+ Thread.sleep(1000);
+ System.out.println("Value = " + (r.nextInt(6) + 1));
+ }
+ }
+}
+```
+
+When you run the `main` function of this class, a new `Dice` object will be
instantiated and then run indefinitely:
+
+```java
+public class Dice {
+ // other methods
+
+ public static void main(String[] args) throws InterruptedException {
+ Dice d = new Dice();
+ d.playDice();
+ }
+}
+```
+
+### Leaders and followers (and a bit of background)
+
+To achieve this common view in multiple instances of the program, we need each
instance to agree on what the next number in the sequence will be. For example,
the instances must agree that 4 is the first number and 2 is the second number
and 5 is the third number and so on. This is a difficult problem, especially in
the case that any instance may go away at any time, and messages between the
instances can be lost or reordered.
+
+Luckily, there are already algorithms to solve this. Paxos is an abstract
algorithm to implement this kind of agreement, while Zab and Raft are more
practical protocols. This video gives a good overview about how these
algorithms usually look. They all have a similar core.
+
+It would be possible to run the Paxos to agree on each number in the sequence.
However, running Paxos each time can be expensive. What Zab and Raft do is that
they use a Paxos-like algorithm to elect a leader. The leader then decides what
the sequence of events should be, putting them in a log, which the other
instances can then follow to maintain the same state as the leader.
+
+Bookkeeper provides the functionality for the second part of the protocol,
allowing a leader to write events to a log and have multiple followers tailing
the log. However, bookkeeper does not do leader election. You will need a
zookeeper or raft instance for that purpose.
+
+### Why not just use ZooKeeper?
+
+There are a number of reasons:
+
+1. Zookeeper's log is only exposed through a tree like interface. It can be
hard to shoehorn your application into this.
+2. A zookeeper ensemble of multiple machines is limited to one log. You may
want one log per resource, which will become expensive very quickly.
+3. Adding extra machines to a zookeeper ensemble does not increase capacity
nor throughput.
+
+Bookkeeper can be seen as a means of exposing ZooKeeper's replicated log to
applications in a scalable fashion. ZooKeeper is still used by BookKeeper,
however, to maintain consistency guarantees, though clients don't need to
interact with ZooKeeper directly.
+
+### Electing a leader
+
+We'll use zookeeper to elect a leader. A zookeeper instance will have started
locally when you started the localbookie application above. To verify it's
running, run the following command.
+
+```shell
+$ echo stat | nc localhost 2181
+Zookeeper version: 3.4.6-1569965, built on 02/20/2014 09:09 GMT
+Clients:
+ /127.0.0.1:59343[1](queued=0,recved=40,sent=41)
+ /127.0.0.1:49354[1](queued=0,recved=11,sent=11)
+ /127.0.0.1:49361[0](queued=0,recved=1,sent=0)
+ /127.0.0.1:59344[1](queued=0,recved=38,sent=39)
+ /127.0.0.1:59345[1](queued=0,recved=38,sent=39)
+ /127.0.0.1:59346[1](queued=0,recved=38,sent=39)
+
+Latency min/avg/max: 0/0/23
+Received: 167
+Sent: 170
+Connections: 6
+Outstanding: 0
+Zxid: 0x11
+Mode: standalone
+Node count: 16
+```
+
+To interact with zookeeper, we'll use the Curator client rather than the stock
zookeeper client. Getting things right with the zookeeper client can be tricky,
and curator removes a lot of the pointy corners for you. In fact, curator even
provides a leader election recipe, so we need to do very little work to get
leader election in our application.
+
+```java
+public class Dice extends LeaderSelectorListenerAdapter implements Closeable {
+
+ final static String ZOOKEEPER_SERVER = "127.0.0.1:2181";
+ final static String ELECTION_PATH = "/dice-elect";
+
+ ...
+
+ Dice() throws InterruptedException {
+ curator = CuratorFrameworkFactory.newClient(ZOOKEEPER_SERVER,
+ 2000, 10000, new ExponentialBackoffRetry(1000, 3));
+ curator.start();
+ curator.blockUntilConnected();
+
+ leaderSelector = new LeaderSelector(curator, ELECTION_PATH, this);
+ leaderSelector.autoRequeue();
+ leaderSelector.start();
+ }
+```
+
+In the constructor for Dice, we need to create the curator client. We specify
four things when creating the client, the location of the zookeeper service,
the session timeout, the connect timeout and the retry policy.
+
+The session timeout is a zookeeper concept. If the zookeeper server doesn't
hear anything from the client for this amount of time, any leases which the
client holds will be timed out. This is important in leader election. For
leader election, the curator client will take a lease on ELECTION_PATH. The
first instance to take the lease will become leader and the rest will become
followers. However, their claim on the lease will remain in the cue. If the
first instance then goes away, due to [...]
+
+Finally, you'll have noticed that Dice now extends
LeaderSelectorListenerAdapter and implements Closeable. Closeable is there to
close the resource we have initialized in the constructor, the curator client
and the leaderSelector. LeaderSelectorListenerAdapter is a callback that the
leaderSelector uses to notify the instance that it is now the leader. It is
passed as the third argument to the LeaderSelector constructor.
+
+```java
+ @Override
+ public void takeLeadership(CuratorFramework client)
+ throws Exception {
+ synchronized (this) {
+ leader = true;
+ try {
+ while (true) {
+ this.wait();
+ }
+ } catch (InterruptedException ie) {
+ Thread.currentThread().interrupt();
+ leader = false;
+ }
+ }
+ }
+```
+
+takeLeadership() is the callback called by LeaderSelector when the instance is
leader. It should only return when the instance wants to give up leadership. In
our case, we never do so we wait on the current object until we're interrupted.
To signal to the rest of the program that we are leader we set a volatile
boolean called leader to true. This is unset after we are interrupted.
+
+```java
+ void playDice() throws InterruptedException {
+ while (true) {
+ while (leader) {
+ Thread.sleep(1000);
+ System.out.println("Value = " + (r.nextInt(6) + 1)
+ + ", isLeader = " + leader);
+ }
+ }
+ }
+```
+
+Finally, we modify the `playDice` function to only generate random numbers
when it is the leader.
+
+Run two instances of the program in two different terminals. You'll see that
one becomes leader and prints numbers and the other just sits there.
+
+Now stop the leader using Control-Z. This will pause the process, but it won't
kill it. You will be dropped back to the shell in that terminal. After a couple
of seconds, the session timeout, you will see that the other instance has
become the leader. Zookeeper will guarantee that only one instance is selected
as leader at any time.
+
+Now go back to the shell that the original leader was on and wake up the
process using fg. You'll see something like the following:
+
+```shell
+...
+...
+Value = 4, isLeader = true
+Value = 4, isLeader = true
+^Z
+[1]+ Stopped mvn exec:java
-Dexec.mainClass=org.apache.bookkeeper.Dice
+$ fg
+mvn exec:java -Dexec.mainClass=org.apache.bookkeeper.Dice
+Value = 3, isLeader = true
+Value = 1, isLeader = false
+```
diff --git a/site/docs/4.5.0/api/overview.md b/site/docs/4.5.0/api/overview.md
new file mode 100644
index 0000000..3eb6492
--- /dev/null
+++ b/site/docs/4.5.0/api/overview.md
@@ -0,0 +1,17 @@
+---
+title: BookKeeper API
+---
+
+BookKeeper offers a few APIs that applications can use to interact with it:
+
+* The [ledger API](../ledger-api) is a lower-level API that enables you to
interact with {% pop ledgers %} directly
+* The [Ledger Advanced API)(../ledger-adv-api) is an advanced extension to
[Ledger API](../ledger-api) to provide more flexibilities to applications.
+* The [DistributedLog API](../distributedlog-api) is a higher-level API that
provides convenient abstractions.
+
+## Trade-offs
+
+The `Ledger API` provides direct access to ledgers and thus enables you to use
BookKeeper however you'd like.
+
+However, in most of use cases, if you want a `log stream`-like abstraction, it
requires you to manage things like tracking list of ledgers,
+managing rolling ledgers and data retention on your own. In such cases, you
are recommended to use [DistributedLog API](../distributedlog-api),
+with semantics resembling continous log streams from the standpoint of
applications.
diff --git a/site/docs/4.5.0/deployment/dcos.md
b/site/docs/4.5.0/deployment/dcos.md
new file mode 100644
index 0000000..5f0c732
--- /dev/null
+++ b/site/docs/4.5.0/deployment/dcos.md
@@ -0,0 +1,142 @@
+---
+title: Deploying BookKeeper on DC/OS
+subtitle: Get up and running easily on an Apache Mesos cluster
+logo: img/dcos-logo.png
+---
+
+[DC/OS](https://dcos.io/) (the <strong>D</strong>ata<strong>C</strong>enter
<strong>O</strong>perating <strong>S</strong>ystem) is a distributed operating
system used for deploying and managing applications and systems on [Apache
Mesos](http://mesos.apache.org/). DC/OS is an open-source tool created and
maintained by [Mesosphere](https://mesosphere.com/).
+
+BookKeeper is available as a [DC/OS
package](http://universe.dcos.io/#/package/bookkeeper/version/latest) from the
[Mesosphere DC/OS Universe](http://universe.dcos.io/#/packages).
+
+## Prerequisites
+
+In order to run BookKeeper on DC/OS, you will need:
+
+* DC/OS version [1.8](https://dcos.io/docs/1.8/) or higher
+* A DC/OS cluster with at least three nodes
+* The [DC/OS CLI tool](https://dcos.io/docs/1.8/usage/cli/install/) installed
+
+Each node in your DC/OS-managed Mesos cluster must have at least:
+
+* 1 CPU
+* 1 GB of memory
+* 10 GB of total persistent disk storage
+
+## Installing BookKeeper
+
+```shell
+$ dcos package install bookkeeper --yes
+```
+
+This command will:
+
+* Install the `bookkeeper` subcommand for the `dcos` CLI tool
+* Start a single {% pop bookie %} on the Mesos cluster with the [default
configuration](../../reference/config)
+
+The bookie that is automatically started up uses the host mode of the network
and by default exports the service at `agent_ip:3181`.
+
+> If you run `dcos package install bookkeeper` without setting the `--yes`
flag, the install will run in interactive mode. For more information on the
`package install` command, see the [DC/OS
docs](https://docs.mesosphere.com/latest/cli/command-reference/dcos-package/dcos-package-install/).
+
+### Services
+
+To watch BookKeeper start up, click on the **Services** tab in the DC/OS [user
interface](https://docs.mesosphere.com/latest/gui/) and you should see the
`bookkeeper` package listed:
+
+
+
+### Tasks
+
+To see which tasks have started, click on the `bookkeeper` service and you'll
see an interface that looks like this;
+
+
+
+## Scaling BookKeeper
+
+Once the first {% pop bookie %} has started up, you can click on the **Scale**
tab to scale up your BookKeeper ensemble by adding more bookies (or scale down
the ensemble by removing bookies).
+
+
+
+## ZooKeeper Exhibitor
+
+ZooKeeper contains the information for all bookies in the ensemble. When
deployed on DC/OS, BookKeeper uses a ZooKeeper instance provided by DC/OS. You
can access a visual UI for ZooKeeper using
[Exhibitor](https://github.com/soabase/exhibitor/wiki), which is available at
[http://master.dcos/exhibitor](http://master.dcos/exhibitor).
+
+
+
+You should see a listing of IP/host information for all bookies under the
`messaging/bookkeeper/ledgers/available` node.
+
+## Client connections
+
+To connect to bookies running on DC/OS using clients running within your Mesos
cluster, you need to specify the ZooKeeper connection string for DC/OS's
ZooKeeper cluster:
+
+```
+master.mesos:2181
+```
+
+This is the *only* ZooKeeper host/port you need to include in your connection
string. Here's an example using the [Java
client](../../api/ledger-api#the-java-ledger-api-client):
+
+```java
+BookKeeper bkClient = new BookKeeper("master.mesos:2181");
+```
+
+If you're connecting using a client running outside your Mesos cluster, you
need to supply the public-facing connection string for your DC/OS ZooKeeper
cluster.
+
+## Configuring BookKeeper
+
+By default, the `bookkeeper` package will start up a BookKeeper ensemble
consisting of one {% pop bookie %} with one CPU, 1 GB of memory, and a 70 MB
persistent volume.
+
+You can supply a non-default configuration when installing the package using a
JSON file. Here's an example command:
+
+```shell
+$ dcos package install bookkeeper \
+ --options=/path/to/config.json
+```
+
+You can then fetch the current configuration for BookKeeper at any time using
the `package describe` command:
+
+```shell
+$ dcos package describe bookkeeper \
+ --config
+```
+
+### Available parameters
+
+> Not all [configurable parameters](../../reference/config) for BookKeeper are
available for BookKeeper on DC/OS. Only the parameters show in the table below
are available.
+
+Param | Type | Description | Default
+:-----|:-----|:------------|:-------
+`name` | String | The name of the DC/OS service. | `bookkeeper`
+`cpus` | Integer | The number of CPU shares to allocate to each {% pop bookie
%}. The minimum is 1. | `1` |
+`instances` | Integer | The number of {% pop bookies %} top run. The minimum
is 1. | `1`
+`mem` | Number | The memory, in MB, to allocate to each BookKeeper task |
`1024.0` (1 GB)
+`volume_size` | Number | The persistent volume size, in MB | `70`
+`zk_client` | String | The connection string for the ZooKeeper client instance
| `master.mesos:2181`
+`service_port` | Integer | The BookKeeper export service port, using `PORT0`
in Marathon | `3181`
+
+### Example JSON configuration
+
+Here's an example JSON configuration object for BookKeeper on DC/OS:
+
+```json
+{
+ "instances": 5,
+ "cpus": 3,
+ "mem": 2048.0,
+ "volume_size": 250
+}
+```
+
+If that configuration were stored in a file called `bk-config.json`, you could
apply that configuration upon installating the BookKeeper package using this
command:
+
+```shell
+$ dcos package install bookkeeper \
+ --options=./bk-config.json
+```
+
+## Uninstalling BookKeeper
+
+You can shut down and uninstall the `bookkeeper` from DC/OS at any time using
the `package uninstall` command:
+
+```shell
+$ dcos package uninstall bookkeeper
+Uninstalled package [bookkeeper] version [4.5.0]
+Thank you for using bookkeeper.
+```
diff --git a/site/docs/4.5.0/deployment/kubernetes.md
b/site/docs/4.5.0/deployment/kubernetes.md
new file mode 100644
index 0000000..f651721
--- /dev/null
+++ b/site/docs/4.5.0/deployment/kubernetes.md
@@ -0,0 +1,4 @@
+---
+title: Deploying BookKeeper on Kubernetes
+logo: img/kubernetes-logo.png
+---
diff --git a/site/docs/latest/deployment/manual.md
b/site/docs/4.5.0/deployment/manual.md
similarity index 99%
copy from site/docs/latest/deployment/manual.md
copy to site/docs/4.5.0/deployment/manual.md
index 654595f..daafd55 100644
--- a/site/docs/latest/deployment/manual.md
+++ b/site/docs/4.5.0/deployment/manual.md
@@ -53,4 +53,4 @@ Once cluster metadata formatting has been completed, your
BookKeeper cluster is
## AutoRecovery
[this guide](../../admin/autorecovery)
--->
\ No newline at end of file
+-->
diff --git a/site/docs/4.5.0/development/codebase.md
b/site/docs/4.5.0/development/codebase.md
new file mode 100644
index 0000000..9a83073
--- /dev/null
+++ b/site/docs/4.5.0/development/codebase.md
@@ -0,0 +1,3 @@
+---
+title: The BookKeeper codebase
+---
diff --git a/site/docs/4.5.0/development/protocol.md
b/site/docs/4.5.0/development/protocol.md
new file mode 100644
index 0000000..6d17aa0
--- /dev/null
+++ b/site/docs/4.5.0/development/protocol.md
@@ -0,0 +1,148 @@
+---
+title: The BookKeeper protocol
+---
+
+BookKeeper uses a special replication protocol for guaranteeing persistent
storage of entries in an ensemble of bookies.
+
+> This document assumes that you have some knowledge of leader election and
log replication and how these can be used in a distributed system. If not, we
recommend reading the [example
application](../../api/ledger-api#example-application) documentation first.
+
+## Ledgers
+
+{% pop Ledgers %} are the basic building block of BookKeeper and the level at
which BookKeeper makes its persistent storage guarantees. A replicated log
consists of an ordered list of ledgers. See [Ledgers to logs](#ledgers-to-logs)
for info on building a replicated log from ledgers.
+
+Ledgers are composed of metadata and {% pop entries %}. The metadata is stored
in ZooKeeper, which provides a *compare-and-swap* (CAS) operation. Entries are
stored on storage nodes known as {% pop bookies %}.
+
+A ledger has a single writer and multiple readers (SWMR).
+
+### Ledger metadata
+
+A ledger's metadata contains the following:
+
+Parameter | Name | Meaning
+:---------|:-----|:-------
+Identifer | | A 64-bit integer, unique within the system
+Ensemble size | **E** | The number of nodes the ledger is stored on
+Write quorum size | **Q<sub>w</sub>** | The number of nodes each entry is
written to. In effect, the max replication for the entry.
+Ack quorum size | **Q<sub>a</sub>** | The number of nodes an entry must be
acknowledged on. In effect, the minimum replication for the entry.
+Current state | | The current status of the ledger. One of `OPEN`, `CLOSED`,
or `IN_RECOVERY`.
+Last entry | | The last entry in the ledger or `NULL` is the current state is
not `CLOSED`.
+
+In addition, each ledger's metadata consists of one or more *fragments*. Each
fragment is either
+
+* the first entry of a fragment or
+* a list of bookies for the fragment.
+
+When creating a ledger, the following invariant must hold:
+
+**E >= Q<sub>w</sub> >= Qa**
+
+Thus, the ensemble size (**E**) must be larger than the write quorum size
(**Q<sub>w</sub>**), which must in turn be larger than the ack quorum size
(**Q<sub>a</sub>**). If that condition does not hold, then the ledger creation
operation will fail.
+
+### Ensembles
+
+When a ledger is created, **E** bookies are chosen for the entries of that
ledger. The bookies are the initial ensemble of the ledger. A ledger can have
multiple ensembles, but an entry has only one ensemble. Changes in the ensemble
involve a new fragment being added to the ledger.
+
+Take the following example. In this ledger, with ensemble size of 3, there are
two fragments and thus two ensembles, one starting at entry 0, the second at
entry 12. The second ensemble differs from the first only by its first element.
This could be because bookie1 has failed and therefore had to be replaced.
+
+First entry | Bookies
+:-----------|:-------
+0 | B1, B2, B3
+12 | B4, B2, B3
+
+### Write quorums
+
+Each entry in the log is written to **Q<sub>w</sub>** nodes. This is
considered the write quorum for that entry. The write quorum is the subsequence
of the ensemble, **Q<sub>w</sub>** in length, and starting at the bookie at
index (entryid % **E**).
+
+For example, in a ledger of **E** = 4, **Q<sub>w</sub>**, and
**Q<sub>a</sub>** = 2, with an ensemble consisting of B1, B2, B3, and B4, the
write quorums for the first 6 entries will be:
+
+Entry | Write quorum
+:-----|:------------
+0 | B1, B2, B3
+1 | B2, B3, B4
+2 | B3, B4, B1
+3 | B4, B1, B2
+4 | B1, B2, B3
+5 | B2, B3, B4
+
+There are only **E** distinct write quorums in any ensemble. If
**Q<sub>w</sub>** = **Q<sub>a</sub>**, then there is only one, as no striping
occurs.
+
+### Ack quorums
+
+The ack quorum for an entry is any subset of the write quorum of size
**Q<sub>a</sub>**. If **Q<sub>a</sub>** bookies acknowledge an entry, it means
it has been fully replicated.
+
+### Guarantees
+
+The system can tolerate **Q<sub>a</sub>** – 1 failures without data loss.
+
+Bookkeeper guarantees that:
+
+1. All updates to a ledger will be read in the same order as they were written.
+2. All clients will read the same sequence of updates from the ledger.
+
+## Writing to ledgers
+
+writer, ensuring that entry ids are sequential is trivial. A bookie
acknowledges a write once it has been persisted to disk and is therefore
durable. Once **Q<sub>a</sub>** bookies from the write quorum acknowledge the
write, the write is acknowledged to the client, but only if all entries with
lower entry ids in the ledger have already been acknowledged to the client.
+
+The entry written contains the ledger id, the entry id, the last add confirmed
and the payload. The last add confirmed is the last entry which had been
acknowledged to the client when this entry was written. Sending this with the
entry speeds up recovery of the ledger in the case that the writer crashes.
+
+Another client can also read entries in the ledger up as far as the last add
confirmed, as we guarantee that all entries thus far have been replicated on Qa
nodes, and therefore all future readers will be able to also read it. However,
to read like this, the ledger should be opened with a non-fencing open.
Otherwise, it would kill the writer.
+
+If a node fails to acknowledge a write, the writer will create a new ensemble
by replacing the failed node in the current ensemble. It creates a new fragment
with this ensemble, starting from the first message that has not been
acknowledged to the client. Creating the new fragment involves making a CAS
write to the metadata. If the CAS write fails, someone else has modified
something in the ledger metadata. This concurrent modification could have been
caused by recovery or {% pop rerepli [...]
+
+### Closing a ledger as a writer
+
+Closing a ledger is straightforward for a writer. The writer makes a CAS write
to the metadata, changing the state to `CLOSED` and setting the last entry of
the ledger to the last entry which we have acknowledged to the client.
+
+If the CAS write fails, it means someone else has modified the metadata. We
reread the metadata, and retry closing as long as the state of the ledger is
still `OPEN`. If the state is `IN_RECOVERY` we send an error to the client. If
the state is `CLOSED` and the last entry is the same as the last entry we have
acknowledged to the client, we complete the close operation successfully. If
the last entry is different from what we have acknowledged to the client, we
send an error to the client.
+
+### Closing a ledger as a reader
+
+A reader can also force a ledger to close. Forcing the ledger to close will
prevent any writer from adding new entries to the ledger. This is called {% pop
fencing %}. This can occur when a writer has crashed or become unavailable, and
a new writer wants to take over writing to the log. The new writer must ensure
that it has seen all updates from the previous writer, and prevent the previous
writer from making any new updates before making any updates of its own.
+
+To recover a ledger, we first update the state in the metadata to IN_RECOVERY.
We then send a fence message to all the bookies in the last fragment of the
ledger. When a bookie receives a fence message for a ledger, the fenced state
of the ledger is persisted to disk. Once we receive a response from at least
(**Q<sub>w</sub>** - **Q<sub>a</sub>**)+1 bookies from each write quorum in the
ensemble, the ledger is fenced.
+
+By ensuring we have received a response from at last (**Q<sub>w</sub>** -
**Q<sub>a</sub>**) + 1 bookies in each write quorum, we ensure that, if the old
writer is alive and tries to add a new entry there will be no write quorum in
which Qa bookies will accept the write. If the old writer tries to update the
ensemble, it will fail on the CAS metadata write, and then see that the ledger
is in IN_RECOVERY state, and that it therefore shouldn’t try to write to it.
+
+The old writer will be able to write entries to individual bookies (we can’t
guarantee that the fence message reaches all bookies), but as it will not be
able reach ack quorum, it will not be able to send a success response to its
client. The client will get a LedgerFenced error instead.
+
+It is important to note that when you get a ledger fenced message for an
entry, it doesn’t mean that the entry has not been written. It means that the
entry may or may not have been written, and this can only be determined after
the ledger is recovered. In effect, LedgerFenced should be treated like a
timeout.
+
+Once the ledger is fenced, recovery can begin. Recovery means finding the last
entry of the ledger and closing the ledger. To find the last entry of the
ledger, the client asks all bookies for the highest last add confirmed value
they have seen. It waits until it has received a response at least
(**Q<sub>w</sub>** - **Q<sub>a</sub>**) + 1 bookies from each write quorum, and
takes the highest response as the entry id to start reading forward from. It
then starts reading forward in the led [...]
+
+## Ledgers to logs
+
+In BookKeeper, {% pop ledgers %} can be used to build a replicated log for
your system. All guarantees provided by BookKeeper are at the ledger level.
Guarantees on the whole log can be built using the ledger guarantees and any
consistent datastore with a compare-and-swap (CAS) primitive. BookKeeper uses
ZooKeeper as the datastore but others could theoretically be used.
+
+A log in BookKeeper is built from some number of ledgers, with a fixed order.
A ledger represents a single segment of the log. A ledger could be the whole
period that one node was the leader, or there could be multiple ledgers for a
single period of leadership. However, there can only ever be one leader that
adds entries to a single ledger. Ledgers cannot be reopened for writing once
they have been closed/recovered.
+
+> BookKeeper does *not* provide leader election. You must use a system like
ZooKeeper for this.
+
+In many cases, leader election is really leader suggestion. Multiple nodes
could think that they are leader at any one time. It is the job of the log to
guarantee that only one can write changes to the system.
+
+### Opening a log
+
+Once a node thinks it is leader for a particular log, it must take the
following steps:
+
+1. Read the list of ledgers for the log
+1. {% pop Fence %} the last two ledgers in the list. Two ledgers are fenced
because because the writer may be writing to the second-to-last ledger while
adding the last ledger to the list.
+1. Create a new ledger
+1. Add the new ledger to the ledger list
+1. Write the new ledger back to the datastore using a CAS operation
+
+The fencing in step 2 and the CAS operation in step 5 prevent two nodes from
thinking that they have leadership at any one time.
+
+The CAS operation will fail if the list of ledgers has changed between reading
it and writing back the new list. When the CAS operation fails, the leader must
start at step 1 again. Even better, they should check that they are in fact
still the leader with the system that is providing leader election. The
protocol will work correctly without this step, though it will be able to make
very little progress if two nodes think they are leader and are duelling for
the log.
+
+The node must not serve any writes until step 5 completes successfully.
+
+### Rolling ledgers
+
+The leader may wish to close the current ledger and open a new one every so
often. Ledgers can only be deleted as a whole. If you don't roll the log, you
won't be able to clean up old entries in the log without a leader change. By
closing the current ledger and adding a new one, the leader allows the log to
be truncated whenever that data is no longer needed. The steps for rolling the
log is similar to those for creating a new ledger.
+
+1. Create a new ledger
+1. Add the new ledger to the ledger list
+1. Write the new ledger list to the datastore using CAS
+1. Close the previous ledger
+
+By deferring the closing of the previous ledger until step 4, we can continue
writing to the log while we perform metadata update operations to add the new
ledger. This is safe as long as you fence the last 2 ledgers when acquiring
leadership.
+
diff --git a/site/docs/4.5.0/example.md b/site/docs/4.5.0/example.md
new file mode 100644
index 0000000..7dbc697
--- /dev/null
+++ b/site/docs/4.5.0/example.md
@@ -0,0 +1,6 @@
+---
+title: Example doc
+subtitle: Just for experimentation purposes.
+---
+
+{% pop ledger %}
diff --git a/site/docs/4.5.0/getting-started/concepts.md
b/site/docs/4.5.0/getting-started/concepts.md
new file mode 100644
index 0000000..7a3c928
--- /dev/null
+++ b/site/docs/4.5.0/getting-started/concepts.md
@@ -0,0 +1,202 @@
+---
+title: BookKeeper concepts and architecture
+subtitle: The core components and how they work
+prev: ../run-locally
+---
+
+BookKeeper is a service that provides persistent storage of streams of log
[entries](#entries)---aka *records*---in sequences called [ledgers](#ledgers).
BookKeeper replicates stored entries across multiple servers.
+
+## Basic terms
+
+In BookKeeper:
+
+* each unit of a log is an [*entry*](#entries) (aka record)
+* streams of log entries are called [*ledgers*](#ledgers)
+* individual servers storing ledgers of entries are called
[*bookies*](#bookies)
+
+BookKeeper is designed to be reliable and resilient to a wide variety of
failures. Bookies can crash, corrupt data, or discard data, but as long as
there are enough bookies behaving correctly in the ensemble the service as a
whole will behave correctly.
+
+## Entries
+
+> **Entries** contain the actual data written to ledgers, along with some
important metadata.
+
+BookKeeper entries are sequences of bytes that are written to
[ledgers](#ledgers). Each entry has the following fields:
+
+Field | Java type | Description
+:-----|:----------|:-----------
+Ledger number | `long` | The ID of the ledger to which the entry has been
written
+Entry number | `long` | The unique ID of the entry
+Last confirmed (LC) | `long` | The ID of the last recorded entry
+Data | `byte[]` | The entry's data (written by the client application)
+Authentication code | `byte[]` | The message auth code, which includes *all*
other fields in the entry
+
+## Ledgers
+
+> **Ledgers** are the basic unit of storage in BookKeeper.
+
+Ledgers are sequences of entries, while each entry is a sequence of bytes.
Entries are written to a ledger:
+
+* sequentially, and
+* at most once.
+
+This means that ledgers have *append-only* semantics. Entries cannot be
modified once they've been written to a ledger. Determining the proper write
order is the responsbility of [client applications](#clients).
+
+## Clients and APIs
+
+> BookKeeper clients have two main roles: they create and delete ledgers, and
they read entries from and write entries to ledgers.
+>
+> BookKeeper provides both a lower-level and a higher-level API for ledger
interaction.
+
+There are currently two APIs that can be used for interacting with BookKeeper:
+
+* The [ledger API](../../api/ledger-api) is a lower-level API that enables you
to interact with {% pop ledgers %} directly.
+* The [DistributedLog API](../../api/distributedlog-api) is a higher-level API
that enables you to use BookKeeper without directly interacting with ledgers.
+
+In general, you should choose the API based on how much granular control you
need over ledger semantics. The two APIs can also both be used within a single
application.
+
+## Bookies
+
+> **Bookies** are individual BookKeeper servers that handle ledgers (more
specifically, fragments of ledgers). Bookies function as part of an ensemble.
+
+A bookie is an individual BookKeeper storage server. Individual bookies store
fragments of ledgers, not entire ledgers (for the sake of performance). For any
given ledger **L**, an *ensemble* is the group of bookies storing the entries
in **L**.
+
+Whenever entries are written to a ledger, those entries are {% pop striped %}
across the ensemble (written to a sub-group of bookies rather than to all
bookies).
+
+### Motivation
+
+> BookKeeper was initially inspired by the NameNode server in HDFS but its
uses now extend far beyond this.
+
+The initial motivation for BookKeeper comes from the
[Hadoop](http://hadoop.apache.org/) ecosystem. In the [Hadoop Distributed File
System](https://wiki.apache.org/hadoop/HDFS) (HDFS), a special node called the
[NameNode](https://wiki.apache.org/hadoop/NameNode) logs all operations in a
reliable fashion, which ensures that recovery is possible in case of crashes.
+
+The NameNode, however, served only as initial inspiration for BookKeeper. The
applications for BookKeeper extend far beyond this and include essentially any
application that requires an append-based storage system. BookKeeper provides a
number of advantages for such applications:
+
+* Highly efficient writes
+* High fault tolerance via replication of messages within ensembles of bookies
+* High throughput for write operations via {% pop striping %} (across as many
bookies as you wish)
+
+## Metadata storage
+
+BookKeeper requires a metadata storage service to store information related to
[ledgers](#ledgers) and available bookies. BookKeeper currently uses
[ZooKeeper](https://zookeeper.apache.org) for this and other tasks.
+
+## Data management in bookies
+
+Bookies manage data in a
[log-structured](https://en.wikipedia.org/wiki/Log-structured_file_system) way,
which is implemented using three types of files:
+
+* [journals](#journals)
+* [entry logs](#entry-logs)
+* [index files](#index-files)
+
+### Journals
+
+A journal file contains BookKeeper transaction logs. Before any update to a
ledger takes place, the bookie ensures that a transaction describing the update
is written to non-volatile storage. A new journal file is created once the
bookie starts or the older journal file reaches the journal file size threshold.
+
+### Entry logs
+
+An entry log file manages the written entries received from BookKeeper
clients. Entries from different ledgers are aggregated and written
sequentially, while their offsets are kept as pointers in a [ledger
cache](#ledger-cache) for fast lookup.
+
+A new entry log file is created once the bookie starts or the older entry log
file reaches the entry log size threshold. Old entry log files are removed by
the Garbage Collector Thread once they are not associated with any active
ledger.
+
+### Index files
+
+An index file is created for each ledger, which comprises a header and several
fixed-length index pages that record the offsets of data stored in entry log
files.
+
+Since updating index files would introduce random disk I/O index files are
updated lazily by a sync thread running in the background. This ensures speedy
performance for updates. Before index pages are persisted to disk, they are
gathered in a ledger cache for lookup.
+
+### Ledger cache
+
+Ledger indexes pages are cached in a memory pool, which allows for more
efficient management of disk head scheduling.
+
+### Adding entries
+
+When a client instructs a {% pop bookie %} to write an entry to a ledger, the
entry will go through the following steps to be persisted on disk:
+
+1. The entry is appended to an [entry log](#entry-logs)
+1. The index of the entry is updated in the [ledger cache](#ledger-cache)
+1. A transaction corresponding to this entry update is appended to the
[journal](#journals)
+1. A response is sent to the BookKeeper client
+
+> For performance reasons, the entry log buffers entries in memory and commits
them in batches, while the ledger cache holds index pages in memory and flushes
them lazily. This process is described in more detail in the [Data
flush](#data-flush) section below.
+
+### Data flush
+
+Ledger index pages are flushed to index files in the following two cases:
+
+* The ledger cache memory limit is reached. There is no more space available
to hold newer index pages. Dirty index pages will be evicted from the ledger
cache and persisted to index files.
+* A background thread synchronous thread is responsible for flushing index
pages from the ledger cache to index files periodically.
+
+Besides flushing index pages, the sync thread is responsible for rolling
journal files in case that journal files use too much disk space. The data
flush flow in the sync thread is as follows:
+
+* A `LastLogMark` is recorded in memory. The `LastLogMark` indicates that
those entries before it have been persisted (to both index and entry log files)
and contains two parts:
+ 1. A `txnLogId` (the file ID of a journal)
+ 1. A `txnLogPos` (offset in a journal)
+* Dirty index pages are flushed from the ledger cache to the index file, and
entry log files are flushed to ensure that all buffered entries in entry log
files are persisted to disk.
+
+ Ideally, a bookie only needs to flush index pages and entry log files that
contain entries before `LastLogMark`. There is, however, no such information in
the ledger and entry log mapping to journal files. Consequently, the thread
flushes the ledger cache and entry log entirely here, and may flush entries
after the `LastLogMark`. Flushing more is not a problem, though, just redundant.
+* The `LastLogMark` is persisted to disk, which means that entries added
before `LastLogMark` whose entry data and index page were also persisted to
disk. It is now time to safely remove journal files created earlier than
`txnLogId`.
+
+If the bookie has crashed before persisting `LastLogMark` to disk, it still
has journal files containing entries for which index pages may not have been
persisted. Consequently, when this bookie restarts, it inspects journal files
to restore those entries and data isn't lost.
+
+Using the above data flush mechanism, it is safe for the sync thread to skip
data flushing when the bookie shuts down. However, in the entry logger it uses
a buffered channel to write entries in batches and there might be data buffered
in the buffered channel upon a shut down. The bookie needs to ensure that the
entry log flushes its buffered data during shutdown. Otherwise, entry log files
become corrupted with partial entries.
+
+### Data compaction
+
+On bookies, entries of different ledgers are interleaved in entry log files. A
bookie runs a garbage collector thread to delete un-associated entry log files
to reclaim disk space. If a given entry log file contains entries from a ledger
that has not been deleted, then the entry log file would never be removed and
the occupied disk space never reclaimed. In order to avoid such a case, a
bookie server compacts entry log files in a garbage collector thread to reclaim
disk space.
+
+There are two kinds of compaction running with different frequency: minor
compaction and major compaction. The differences between minor compaction and
major compaction lies in their threshold value and compaction interval.
+
+* The garbage collection threshold is the size percentage of an entry log file
occupied by those undeleted ledgers. The default minor compaction threshold is
0.2, while the major compaction threshold is 0.8.
+* The garbage collection interval is how frequently to run the compaction. The
default minor compaction interval is 1 hour, while the major compaction
threshold is 1 day.
+
+> If either the threshold or interval is set to less than or equal to zero,
compaction is disabled.
+
+The data compaction flow in the garbage collector thread is as follows:
+
+* The thread scans entry log files to get their entry log metadata, which
records a list of ledgers comprising an entry log and their corresponding
percentages.
+* With the normal garbage collection flow, once the bookie determines that a
ledger has been deleted, the ledger will be removed from the entry log metadata
and the size of the entry log reduced.
+* If the remaining size of an entry log file reaches a specified threshold,
the entries of active ledgers in the entry log will be copied to a new entry
log file.
+* Once all valid entries have been copied, the old entry log file is deleted.
+
+## ZooKeeper metadata
+
+BookKeeper requires a ZooKeeper installation for storing [ledger](#ledger)
metadata. Whenever you construct a
[`BookKeeper`](../../api/javadoc/org/apache/bookkeeper/client/BookKeeper)
client object, you need to pass a list of ZooKeeper servers as a parameter to
the constructor, like this:
+
+```java
+String zkConnectionString = "127.0.0.1:2181";
+BookKeeper bkClient = new BookKeeper(zkConnectionString);
+```
+
+> For more info on using the BookKeeper Java client, see [this
guide](../../api/ledger-api#the-java-ledger-api-client).
+
+## Ledger manager
+
+A *ledger manager* handles ledgers' metadata (which is stored in ZooKeeper).
BookKeeper offers two types of ledger managers: the [flat ledger
manager](#flat-ledger-manager) and the [hierarchical ledger
manager](#hierarchical-ledger-manager). Both ledger managers extend the
[`AbstractZkLedgerManager`](../../api/javadoc/org/apache/bookkeeper/meta/AbstractZkLedgerManager)
abstract class.
+
+> #### Use the flat ledger manager in most cases
+> The flat ledger manager is the default and is recommended for nearly all use
cases. The hierarchical ledger manager is better suited only for managing very
large numbers of BookKeeper ledgers (> 50,000).
+
+### Flat ledger manager
+
+The *flat ledger manager*, implemented in the
[`FlatLedgerManager`](../../api/javadoc/org/apache/bookkeeper/meta/FlatLedgerManager.html)
class, stores all ledgers' metadata in child nodes of a single ZooKeeper path.
The flat ledger manager creates [sequential
nodes](https://zookeeper.apache.org/doc/trunk/zookeeperProgrammers.html#Sequence+Nodes+--+Unique+Naming)
to ensure the uniqueness of the ledger ID and prefixes all nodes with `L`.
Bookie servers manage their own active ledgers in a [...]
+
+The flat ledger manager's garbage collection follow proceeds as follows:
+
+* All existing ledgers are fetched from ZooKeeper (`zkActiveLedgers`)
+* All ledgers currently active within the bookie are fetched
(`bkActiveLedgers`)
+* The currently actively ledgers are looped through to determine which ledgers
don't currently exist in ZooKeeper. Those are then garbage collected.
+* The *hierarchical ledger manager* stores ledgers' metadata in two-level
[znodes](https://zookeeper.apache.org/doc/current/zookeeperOver.html#Nodes+and+ephemeral+nodes).
+
+### Hierarchical ledger manager
+
+The *hierarchical ledger manager*, implemented in the
[`HierarchicalLedgerManager`](../../api/javadoc/org/apache/bookkeeper/meta/HierarchicalLedgerManager)
class, first obtains a global unique ID from ZooKeeper using an
[`EPHEMERAL_SEQUENTIAL`](https://zookeeper.apache.org/doc/current/api/org/apache/zookeeper/CreateMode.html#EPHEMERAL_SEQUENTIAL)
znode. Since ZooKeeper's sequence counter has a format of `%10d` (10 digits
with 0 padding, for example `<path>0000000001`), the hierarchical l [...]
+
+```shell
+{level1 (2 digits)}{level2 (4 digits)}{level3 (4 digits)}
+```
+
+These three parts are used to form the actual ledger node path to store ledger
metadata:
+
+```shell
+{ledgers_root_path}/{level1}/{level2}/L{level3}
+```
+
+For example, ledger 0000000001 is split into three parts, 00, 0000, and 00001,
and stored in znode `/{ledgers_root_path}/00/0000/L0001`. Each znode could have
as many 10,000 ledgers, which avoids the problem of the child list being larger
than the maximum ZooKeeper packet size (which is the
[limitation](https://issues.apache.org/jira/browse/BOOKKEEPER-39) that
initially prompted the creation of the hierarchical ledger manager).
diff --git a/site/docs/4.5.0/getting-started/installation.md
b/site/docs/4.5.0/getting-started/installation.md
new file mode 100644
index 0000000..ed77bce
--- /dev/null
+++ b/site/docs/4.5.0/getting-started/installation.md
@@ -0,0 +1,74 @@
+---
+title: BookKeeper installation
+subtitle: Download or clone BookKeeper and build it locally
+next: ../run-locally
+---
+
+{% capture download_url %}http://apache.claz.org/bookkeeper/bookkeeper-{{
site.stable_release }}/bookkeeper-{{ site.stable_release }}-src.tar.gz{%
endcapture %}
+
+You can install BookKeeper either by [downloading](#download) a
[GZipped](http://www.gzip.org/) tarball package or [cloning](#clone) the
BookKeeper repository.
+
+## Requirements
+
+* [Unix environment](http://www.opengroup.org/unix)
+* [Java Development Kit
1.6](http://www.oracle.com/technetwork/java/javase/downloads/index.html) or
later
+* [Maven 3.0](https://maven.apache.org/install.html) or later
+
+## Download
+
+You can download Apache BookKeeper releases from one of many [Apache
mirrors](http://www.apache.org/dyn/closer.cgi/bookkeeper). Here's an example
for the [apache.claz.org](http://apache.claz.org/bookkeeper) mirror:
+
+```shell
+$ curl -O {{ download_url }}
+$ tar xvf bookkeeper-{{ site.stable_release }}-src.tar.gz
+$ cd bookkeeper-{{ site.stable_release }}
+```
+
+## Clone
+
+To build BookKeeper from source, clone the repository, either from the [GitHub
mirror]({{ site.github_repo }}) or from the [Apache
repository](http://git.apache.org/bookkeeper.git/):
+
+```shell
+# From the GitHub mirror
+$ git clone {{ site.github_repo}}
+
+# From Apache directly
+$ git clone git://git.apache.org/bookkeeper.git/
+```
+
+## Build using Maven
+
+Once you have the BookKeeper on your local machine, either by
[downloading](#download) or [cloning](#clone) it, you can then build BookKeeper
from source using Maven:
+
+```shell
+$ mvn package
+```
+
+> You can skip tests by adding the `-DskipTests` flag when running `mvn
package`.
+
+### Useful Maven commands
+
+Some other useful Maven commands beyond `mvn package`:
+
+Command | Action
+:-------|:------
+`mvn clean` | Removes build artifacts
+`mvn compile` | Compiles JAR files from Java sources
+`mvn compile findbugs:findbugs` | Compile using the Maven
[FindBugs](http://gleclaire.github.io/findbugs-maven-plugin) plugin
+`mvn install` | Install the BookKeeper JAR locally in your local Maven cache
(usually in the `~/.m2` directory)
+`mvn deploy` | Deploy the BookKeeper JAR to the Maven repo (if you have the
proper credentials)
+`mvn verify` | Performs a wide variety of verification and validation tasks
+`mvn apache-rat:check` | Run Maven using the [Apache
Rat](http://creadur.apache.org/rat/apache-rat-plugin/) plugin
+`mvn compile javadoc:aggregate` | Build Javadocs locally
+`mvn package assembly:single` | Build a complete distribution using the Maven
[Assembly](http://maven.apache.org/plugins/maven-assembly-plugin/) plugin
+
+## Package directory
+
+The BookKeeper project contains several subfolders that you should be aware of:
+
+Subfolder | Contains
+:---------|:--------
+[`bookkeeper-server`]({{ site.github_repo }}/tree/master/bookkeeper-server) |
The BookKeeper server and client
+[`bookkeeper-benchmark`]({{ site.github_repo
}}/tree/master/bookkeeper-benchmark) | A benchmarking suite for measuring
BookKeeper performance
+[`bookkeeper-stats`]({{ site.github_repo }}/tree/master/bookkeeper-stats) | A
BookKeeper stats library
+[`bookkeeper-stats-providers`]({{ site.github_repo
}}/tree/master/bookkeeper-stats-providers) | BookKeeper stats providers
diff --git a/site/docs/4.5.0/getting-started/run-locally.md
b/site/docs/4.5.0/getting-started/run-locally.md
new file mode 100644
index 0000000..ab33642
--- /dev/null
+++ b/site/docs/4.5.0/getting-started/run-locally.md
@@ -0,0 +1,16 @@
+---
+title: Run bookies locally
+prev: ../installation
+next: ../concepts
+toc_disable: true
+---
+
+{% pop Bookies %} are individual BookKeeper servers. You can run an ensemble
of bookies locally on a single machine using the
[`localbookie`](../../reference/cli#bookkeeper-localbookie) command of the
`bookkeeper` CLI tool and specifying the number of bookies you'd like to
include in the ensemble.
+
+This would start up an ensemble with 10 bookies:
+
+```shell
+$ bookeeper-server/bin/bookeeper localbookie 10
+```
+
+> When you start up an ensemble using `localbookie`, all bookies run in a
single JVM process.
diff --git a/site/docs/latest/overview/overview.md
b/site/docs/4.5.0/overview/overview.md
similarity index 92%
copy from site/docs/latest/overview/overview.md
copy to site/docs/4.5.0/overview/overview.md
index e17bfaa..f2ff5b8 100644
--- a/site/docs/latest/overview/overview.md
+++ b/site/docs/4.5.0/overview/overview.md
@@ -1,5 +1,5 @@
---
-title: Apache BookKeeper 4.5.0-SNAPSHOT Documentation
+title: Apache BookKeeper 4.5.0 Documentation
---
<!--
Licensed to the Apache Software Foundation (ASF) under one
@@ -20,7 +20,7 @@ specific language governing permissions and limitations
under the License.
-->
-This documentation is for Apache BookKeeper version `{{ site.latest_version
}}`.
+This documentation is for Apache BookKeeper version `4.5.0`.
Apache BookKeeper is a scalable, fault tolerant and low latency storage
service optimized for realtime workloads.
It offers `durability`, `replication` and `strong consistency` as essentials
for building reliable real-time applications.
@@ -34,7 +34,7 @@ It is suitable for being used in following scenerios:
Learn more about Apache BookKeeper and what it can do for your organization:
-- [Apache BookKeeper {{ site.latest_version }} Release Notes](../releaseNotes)
+- [Apache BookKeeper 4.5.0 Release Notes](../releaseNotes)
Or start using Apache BookKeeper today.
diff --git a/site/docs/4.5.0/overview/releaseNotes.md
b/site/docs/4.5.0/overview/releaseNotes.md
new file mode 100644
index 0000000..c7845ae
--- /dev/null
+++ b/site/docs/4.5.0/overview/releaseNotes.md
@@ -0,0 +1,17 @@
+---
+title: Apache BookKeeper 4.5.0 Release Notes
+---
+
+[provide a summary of this release]
+
+Apache BookKeeper users are encouraged to upgrade to 4.5.0. The technical
details of this release are summarized
+below.
+
+## Highlights
+
+[List the highlights]
+
+## Details
+
+[list to issues list]
+
diff --git a/site/docs/4.5.0/overview/releaseNotesTemplate.md
b/site/docs/4.5.0/overview/releaseNotesTemplate.md
new file mode 100644
index 0000000..c7845ae
--- /dev/null
+++ b/site/docs/4.5.0/overview/releaseNotesTemplate.md
@@ -0,0 +1,17 @@
+---
+title: Apache BookKeeper 4.5.0 Release Notes
+---
+
+[provide a summary of this release]
+
+Apache BookKeeper users are encouraged to upgrade to 4.5.0. The technical
details of this release are summarized
+below.
+
+## Highlights
+
+[List the highlights]
+
+## Details
+
+[list to issues list]
+
diff --git a/site/docs/4.5.0/reference/cli.md b/site/docs/4.5.0/reference/cli.md
new file mode 100644
index 0000000..8beb36f
--- /dev/null
+++ b/site/docs/4.5.0/reference/cli.md
@@ -0,0 +1,10 @@
+---
+title: BookKeeper CLI tool reference
+subtitle: A reference guide to the command-line tools that you can use to
administer BookKeeper
+---
+
+{% include cli.html id="bookkeeper" %}
+
+## The BookKeeper shell
+
+{% include shell.html %}
diff --git a/site/docs/latest/reference/config.md
b/site/docs/4.5.0/reference/config.md
similarity index 90%
copy from site/docs/latest/reference/config.md
copy to site/docs/4.5.0/reference/config.md
index 6a420d0..8997b6b 100644
--- a/site/docs/latest/reference/config.md
+++ b/site/docs/4.5.0/reference/config.md
@@ -6,4 +6,4 @@ subtitle: A reference guide to all of BookKeeper's configurable
parameters
The table below lists parameters that you can set to configure {% pop bookies
%}. All configuration takes place in the `bk_server.conf` file in the
`bookkeeper-server/conf` directory of your [BookKeeper
installation](../../getting-started/installing).
-{% include config.html id="bk_server" %}
\ No newline at end of file
+{% include config.html id="bk_server" %}
diff --git a/site/docs/4.5.0/reference/metrics.md
b/site/docs/4.5.0/reference/metrics.md
new file mode 100644
index 0000000..8bd6fe0
--- /dev/null
+++ b/site/docs/4.5.0/reference/metrics.md
@@ -0,0 +1,3 @@
+---
+title: BookKeeper metrics reference
+---
diff --git a/site/docs/4.5.0/security/overview.md
b/site/docs/4.5.0/security/overview.md
new file mode 100644
index 0000000..62da8ed
--- /dev/null
+++ b/site/docs/4.5.0/security/overview.md
@@ -0,0 +1,21 @@
+---
+title: BookKeeper Security
+next: ../tls
+---
+
+In the 4.5.0 release, the BookKeeper community added a number of features that
can be used, together or separately, to secure a BookKeeper cluster.
+The following security measures are currently supported:
+
+1. Authentication of connections to bookies from clients, using either
[TLS](../tls) or [SASL (Kerberos)](../sasl).
+2. Authentication of connections from clients, bookies, autorecovery daemons
to [ZooKeeper](../zookeeper), when using zookeeper based ledger managers.
+3. Encryption of data transferred between bookies and clients, between bookies
and autorecovery daemons using [TLS](../tls).
+
+It’s worth noting that security is optional - non-secured clusters are
supported, as well as a mix of authenticated, unauthenticated, encrypted and
non-encrypted clients.
+
+NOTE: currently `authorization` is not yet available in `4.5.0`. The Apache
BookKeeper community is looking for adding this feature in subsequent releases.
+
+## Next Steps
+
+- [Encryption and Authentication using TLS](../tls)
+- [Authentication using SASL](../sasl)
+- [ZooKeeper Authentication](../zookeeper)
diff --git a/site/docs/4.5.0/security/sasl.md b/site/docs/4.5.0/security/sasl.md
new file mode 100644
index 0000000..ffb972a
--- /dev/null
+++ b/site/docs/4.5.0/security/sasl.md
@@ -0,0 +1,202 @@
+---
+title: Authentication using SASL
+prev: ../tls
+next: ../zookeeper
+---
+
+Bookies support client authentication via SASL. Currently we only support
GSSAPI (Kerberos). We will start
+with a general description of how to configure `SASL` for bookies, clients and
autorecovery daemons, followed
+by mechanism-specific details and wrap up with some operational details.
+
+## SASL configuration for Bookies
+
+1. Select the mechanisms to enable in the bookies. `GSSAPI` is the only
mechanism currently supported by BookKeeper.
+2. Add a `JAAS` config file for the selected mechanisms as described in the
examples for setting up [GSSAPI (Kerberos)](#kerberos).
+3. Pass the `JAAS` config file location as JVM parameter to each Bookie. For
example:
+
+ ```shell
+ -Djava.security.auth.login.config=/etc/bookkeeper/bookie_jaas.conf
+ ```
+
+4. Enable SASL auth plugin in bookies, by setting
`bookieAuthProviderFactoryClass` to
`org.apache.bookkeeper.sasl.SASLBookieAuthProviderFactory`.
+
+
+ ```shell
+
bookieAuthProviderFactoryClass=org.apache.bookkeeper.sasl.SASLBookieAuthProviderFactory
+ ```
+
+5. If you are running `autorecovery` along with bookies, then you want to
enable SASL auth plugin for `autorecovery`, by setting
+ `clientAuthProviderFactoryClass` to
`org.apache.bookkeeper.sasl.SASLClientProviderFactory`.
+
+ ```shell
+
clientAuthProviderFactoryClass=org.apache.bookkeeper.sasl.SASLClientProviderFactory
+ ```
+
+6. Follow the steps in [GSSAPI (Kerberos)](#kerberos) to configure SASL.
+
+#### <a name="notes"></a> Important Notes
+
+1. `Bookie` is a section name in the JAAS file used by each bookie. This
section tells the bookie which principal to use
+ and the location of the keytab where the principal is stored. It allows
the bookie to login using the keytab specified in this section.
+2. `Auditor` is a section name in the JASS file used by `autorecovery` daemon
(it can be co-run with bookies). This section tells the
+ `autorecovery` daemon which principal to use and the location of the
keytab where the principal is stored. It allows the bookie to
+ login using the keytab specified in this section.
+3. The `Client` section is used to authenticate a SASL connection with
ZooKeeper. It also allows the bookies to set ACLs on ZooKeeper nodes
+ which locks these nodes down so that only the bookies can modify it. It is
necessary to have the same primary name across all bookies.
+ If you want to use a section name other than `Client`, set the system
property `zookeeper.sasl.client` to the appropriate name
+ (e.g `-Dzookeeper.sasl.client=ZKClient`).
+4. ZooKeeper uses `zookeeper` as the service name by default. If you want to
change this, set the system property
+ `zookeeper.sasl.client.username` to the appropriate name (e.g.
`-Dzookeeper.sasl.client.username=zk`).
+
+## SASL configuration for Clients
+
+To configure `SASL` authentication on the clients:
+
+1. Select a `SASL` mechanism for authentication and add a `JAAS` config file
for the selected mechanism as described in the examples for
+ setting up [GSSAPI (Kerberos)](#kerberos).
+2. Pass the `JAAS` config file location as JVM parameter to each client JVM.
For example:
+
+ ```shell
+ -Djava.security.auth.login.config=/etc/bookkeeper/bookkeeper_jaas.conf
+ ```
+
+3. Configure the following properties in bookkeeper `ClientConfiguration`:
+
+ ```shell
+
clientAuthProviderFactoryClass=org.apache.bookkeeper.sasl.SASLClientProviderFactory
+ ```
+
+Follow the steps in [GSSAPI (Kerberos)](#kerberos) to configure SASL for the
selected mechanism.
+
+## <a name="kerberos"></a> Authentication using SASL/Kerberos
+
+### Prerequisites
+
+#### Kerberos
+
+If your organization is already using a Kerberos server (for example, by using
`Active Directory`), there is no need to
+install a new server just for BookKeeper. Otherwise you will need to install
one, your Linux vendor likely has packages
+for `Kerberos` and a short guide on how to install and configure it
([Ubuntu](https://help.ubuntu.com/community/Kerberos),
+[Redhat](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Managing_Smart_Cards/installing-kerberos.html)).
+Note that if you are using Oracle Java, you will need to download JCE policy
files for your Java version and copy them to `$JAVA_HOME/jre/lib/security`.
+
+#### Kerberos Principals
+
+If you are using the organization’s Kerberos or Active Directory server, ask
your Kerberos administrator for a principal
+for each Bookie in your cluster and for every operating system user that will
access BookKeeper with Kerberos authentication
+(via clients and tools).
+
+If you have installed your own Kerberos, you will need to create these
principals yourself using the following commands:
+
+```shell
+sudo /usr/sbin/kadmin.local -q 'addprinc -randkey
bookkeeper/{hostname}@{REALM}'
+sudo /usr/sbin/kadmin.local -q "ktadd -k
/etc/security/keytabs/{keytabname}.keytab bookkeeper/{hostname}@{REALM}"
+```
+
+##### All hosts must be reachable using hostnames
+
+It is a *Kerberos* requirement that all your hosts can be resolved with their
FQDNs.
+
+### Configuring Bookies
+
+1. Add a suitably modified JAAS file similar to the one below to each Bookie’s
config directory, let’s call it `bookie_jaas.conf`
+for this example (note that each bookie should have its own keytab):
+
+ ```
+ Bookie {
+ com.sun.security.auth.module.Krb5LoginModule required
+ useKeyTab=true
+ storeKey=true
+ keyTab="/etc/security/keytabs/bookie.keytab"
+ principal="bookkeeper/bk1.hostname....@example.com";
+ };
+ // ZooKeeper client authentication
+ Client {
+ com.sun.security.auth.module.Krb5LoginModule required
+ useKeyTab=true
+ storeKey=true
+ keyTab="/etc/security/keytabs/bookie.keytab"
+ principal="bookkeeper/bk1.hostname....@example.com";
+ };
+ // If you are running `autorecovery` along with bookies
+ Auditor {
+ com.sun.security.auth.module.Krb5LoginModule required
+ useKeyTab=true
+ storeKey=true
+ keyTab="/etc/security/keytabs/bookie.keytab"
+ principal="bookkeeper/bk1.hostname....@example.com";
+ };
+ ```
+
+ The `Bookie` section in the JAAS file tells the bookie which principal to
use and the location of the keytab where this principal is stored.
+ It allows the bookie to login using the keytab specified in this section.
See [notes](#notes) for more details on Zookeeper’s SASL configuration.
+
+2. Pass the name of the JAAS file as a JVM parameter to each Bookie:
+
+ ```shell
+ -Djava.security.auth.login.config=/etc/bookkeeper/bookie_jaas.conf
+ ```
+
+ You may also wish to specify the path to the `krb5.conf` file
+ (see [JDK’s Kerberos
Requirements](https://docs.oracle.com/javase/8/docs/technotes/guides/security/jgss/tutorials/KerberosReq.html)
for more details):
+
+ ```shell
+ -Djava.security.krb5.conf=/etc/bookkeeper/krb5.conf
+ ```
+
+3. Make sure the keytabs configured in the JAAS file are readable by the
operating system user who is starting the Bookies.
+
+4. Enable SASL authentication plugin in the bookies by setting following
parameters.
+
+ ```shell
+
bookieAuthProviderFactoryClass=org.apache.bookkeeper.sasl.SASLBookieAuthProviderFactory
+ # if you run `autorecovery` along with bookies
+
clientAuthProviderFactoryClass=org.apache.bookkeeper.sasl.SASLClientProviderFactory
+ ```
+
+### Configuring Clients
+
+To configure SASL authentication on the clients:
+
+1. Clients will authenticate to the cluster with their own principal (usually
with the same name as the user running the client),
+ so obtain or create these principals as needed. Then create a `JAAS` file
for each principal. The `BookKeeper` section describes
+ how the clients like writers and readers can connect to the Bookies. The
following is an example configuration for a client using
+ a keytab (recommended for long-running processes):
+
+ ```
+ BookKeeper {
+ com.sun.security.auth.module.Krb5LoginModule required
+ useKeyTab=true
+ storeKey=true
+ keyTab="/etc/security/keytabs/bookkeeper.keytab"
+ principal="bookkeeper-clien...@example.com";
+ };
+ ```
+
+
+2. Pass the name of the JAAS file as a JVM parameter to the client JVM:
+
+ ```shell
+ -Djava.security.auth.login.config=/etc/bookkeeper/bookkeeper_jaas.conf
+ ```
+
+ You may also wish to specify the path to the `krb5.conf` file (see
+ [JDK’s Kerberos
Requirements](https://docs.oracle.com/javase/8/docs/technotes/guides/security/jgss/tutorials/KerberosReq.html)
for more details).
+
+ ```shell
+ -Djava.security.krb5.conf=/etc/bookkeeper/krb5.conf
+ ```
+
+
+3. Make sure the keytabs configured in the `bookkeeper_jaas.conf` are readable
by the operating system user who is starting bookkeeper client.
+
+4. Enable SASL authentication plugin in the client by setting following
parameters.
+
+ ```shell
+
clientAuthProviderFactoryClass=org.apache.bookkeeper.sasl.SASLClientProviderFactory
+ ```
+
+## Enabling Logging for SASL
+
+To enable SASL debug output, you can set `sun.security.krb5.debug` system
property to `true`.
+
diff --git a/site/docs/4.5.0/security/tls.md b/site/docs/4.5.0/security/tls.md
new file mode 100644
index 0000000..cd250ab
--- /dev/null
+++ b/site/docs/4.5.0/security/tls.md
@@ -0,0 +1,210 @@
+---
+title: Encryption and Authentication using TLS
+prev: ../overview
+next: ../sasl
+---
+
+Apache BookKeeper allows clients and autorecovery daemons to communicate over
TLS, although this is not enabled by default.
+
+## Overview
+
+The bookies need their own key and certificate in order to use TLS. Clients
can optionally provide a key and a certificate
+for mutual authentication. Each bookie or client can also be configured with
a truststore, which is used to
+determine which certificates (bookie or client identities) to trust
(authenticate).
+
+The truststore can be configured in many ways. To understand the truststore,
consider the following two examples:
+
+1. the truststore contains one or many certificates;
+2. it contains a certificate authority (CA).
+
+In (1), with a list of certificates, the bookie or client will trust any
certificate listed in the truststore.
+In (2), with a CA, the bookie or client will trust any certificate that was
signed by the CA in the truststore.
+
+(TBD: benefits)
+
+## <a name="bookie-keystore"></a> Generate TLS key and certificate
+
+The first step of deploying TLS is to generate the key and the certificate for
each machine in the cluster.
+You can use Java’s `keytool` utility to accomplish this task. We will generate
the key into a temporary keystore
+initially so that we can export and sign it later with CA.
+
+```shell
+keytool -keystore bookie.keystore.jks -alias localhost -validity {validity}
-genkey
+```
+
+You need to specify two parameters in the above command:
+
+1. `keystore`: the keystore file that stores the certificate. The *keystore*
file contains the private key of
+ the certificate; hence, it needs to be kept safely.
+2. `validity`: the valid time of the certificate in days.
+
+<div class="alert alert-success">
+Ensure that common name (CN) matches exactly with the fully qualified domain
name (FQDN) of the server.
+The client compares the CN with the DNS domain name to ensure that it is
indeed connecting to the desired server, not a malicious one.
+</div>
+
+## Creating your own CA
+
+After the first step, each machine in the cluster has a public-private key
pair, and a certificate to identify the machine.
+The certificate, however, is unsigned, which means that an attacker can create
such a certificate to pretend to be any machine.
+
+Therefore, it is important to prevent forged certificates by signing them for
each machine in the cluster.
+A `certificate authority (CA)` is responsible for signing certificates. CA
works likes a government that issues passports —
+the government stamps (signs) each passport so that the passport becomes
difficult to forge. Other governments verify the stamps
+to ensure the passport is authentic. Similarly, the CA signs the certificates,
and the cryptography guarantees that a signed
+certificate is computationally difficult to forge. Thus, as long as the CA is
a genuine and trusted authority, the clients have
+high assurance that they are connecting to the authentic machines.
+
+```shell
+openssl req -new -x509 -keyout ca-key -out ca-cert -days 365
+```
+
+The generated CA is simply a *public-private* key pair and certificate, and it
is intended to sign other certificates.
+
+The next step is to add the generated CA to the clients' truststore so that
the clients can trust this CA:
+
+```shell
+keytool -keystore bookie.truststore.jks -alias CARoot -import -file ca-cert
+```
+
+NOTE: If you configure the bookies to require client authentication by setting
`sslClientAuthentication` to `true` on the
+[bookie config](../../reference/config), then you must also provide a
truststore for the bookies and it should have all the CA
+certificates that clients keys were signed by.
+
+```shell
+keytool -keystore client.truststore.jks -alias CARoot -import -file ca-cert
+```
+
+In contrast to the keystore, which stores each machine’s own identity, the
truststore of a client stores all the certificates
+that the client should trust. Importing a certificate into one’s truststore
also means trusting all certificates that are signed
+by that certificate. As the analogy above, trusting the government (CA) also
means trusting all passports (certificates) that
+it has issued. This attribute is called the chain of trust, and it is
particularly useful when deploying TLS on a large BookKeeper cluster.
+You can sign all certificates in the cluster with a single CA, and have all
machines share the same truststore that trusts the CA.
+That way all machines can authenticate all other machines.
+
+## Signing the certificate
+
+The next step is to sign all certificates in the keystore with the CA we
generated. First, you need to export the certificate from the keystore:
+
+```shell
+keytool -keystore bookie.keystore.jks -alias localhost -certreq -file cert-file
+```
+
+Then sign it with the CA:
+
+```shell
+openssl x509 -req -CA ca-cert -CAkey ca-key -in cert-file -out cert-signed
-days {validity} -CAcreateserial -passin pass:{ca-password}
+```
+
+Finally, you need to import both the certificate of the CA and the signed
certificate into the keystore:
+
+```shell
+keytool -keystore bookie.keystore.jks -alias CARoot -import -file ca-cert
+keytool -keystore bookie.keystore.jks -alias localhost -import -file
cert-signed
+```
+
+The definitions of the parameters are the following:
+
+1. `keystore`: the location of the keystore
+2. `ca-cert`: the certificate of the CA
+3. `ca-key`: the private key of the CA
+4. `ca-password`: the passphrase of the CA
+5. `cert-file`: the exported, unsigned certificate of the bookie
+6. `cert-signed`: the signed certificate of the bookie
+
+(TBD: add a script to automatically generate truststores and keystores.)
+
+## Configuring Bookies
+
+Bookies support TLS for connections on the same service port. In order to
enable TLS, you need to configure `tlsProvider` to be either
+`JDK` or `OpenSSL`. If `OpenSSL` is configured, it will use
`netty-tcnative-boringssl-static`, which loads a corresponding binding according
+to the platforms to run bookies.
+
+> Current `OpenSSL` implementation doesn't depend on the system installed
OpenSSL library. If you want to leverage the OpenSSL installed on
+the system, you can check [this
example](http://netty.io/wiki/forked-tomcat-native.html) on how to replaces the
JARs on the classpath with
+netty bindings to leverage installed OpenSSL.
+
+The following TLS configs are needed on the bookie side:
+
+```shell
+tlsProvider=OpenSSL
+# key store
+tlsKeyStoreType=JKS
+tlsKeyStore=/var/private/tls/bookie.keystore.jks
+tlsKeyStorePasswordPath=/var/private/tls/bookie.keystore.passwd
+# trust store
+tlsTrustStoreType=JKS
+tlsTrustStore=/var/private/tls/bookie.truststore.jks
+tlsTrustStorePasswordPath=/var/private/tls/bookie.truststore.passwd
+```
+
+NOTE: it is important to restrict access to the store files and corresponding
password files via filesystem permissions.
+
+Optional settings that are worth considering:
+
+1. tlsClientAuthentication=false: Enable/Disable using TLS for authentication.
This config when enabled will authenticate the other end
+ of the communication channel. It should be enabled on both bookies and
clients for mutual TLS.
+2. tlsEnabledCipherSuites= A cipher suite is a named combination of
authentication, encryption, MAC and key exchange
+ algorithm used to negotiate the security settings for a network connection
using TLS network protocol. By default,
+ it is null. [OpenSSL
Ciphers](https://www.openssl.org/docs/man1.0.2/apps/ciphers.html)
+ [JDK
Ciphers](http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites)
+3. tlsEnabledProtocols = TLSv1.2,TLSv1.1,TLSv1 (list out the TLS protocols
that you are going to accept from clients).
+ By default, it is not set.
+
+To verify the bookie's keystore and truststore are setup correctly you can run
the following command:
+
+```shell
+openssl s_client -debug -connect localhost:3181 -tls1
+```
+
+NOTE: TLSv1 should be listed under `tlsEnabledProtocols`.
+
+In the output of this command you should see the server's certificate:
+
+```shell
+-----BEGIN CERTIFICATE-----
+{variable sized random bytes}
+-----END CERTIFICATE-----
+```
+
+If the certificate does not show up or if there are any other error messages
then your keystore is not setup correctly.
+
+## Configuring Clients
+
+TLS is supported only for the new BookKeeper client (BookKeeper versions 4.5.0
and higher), the older clients are not
+supported. The configs for TLS will be the same as bookies.
+
+If client authentication is not required by the bookies, the following is a
minimal configuration example:
+
+```shell
+tlsProvider=OpenSSL
+clientTrustStore=/var/private/tls/client.truststore.jks
+clientTrustStorePasswordPath=/var/private/tls/client.truststore.passwd
+```
+
+If client authentication is required, then a keystore must be created for each
client, and the bookies' truststores must
+trust the certificate in the client's keystore. This may be done using
commands that are similar to what we used for
+the [bookie keystore](#bookie-keystore).
+
+And the following must also be configured:
+
+```shell
+tlsClientAuthentication=true
+clientKeyStore=/var/private/tls/client.keystore.jks
+clientKeyStorePasswordPath=/var/private/tls/client.keystore.passwd
+```
+
+NOTE: it is important to restrict access to the store files and corresponding
password files via filesystem permissions.
+
+(TBD: add example to use tls in bin/bookkeeper script?)
+
+## Enabling TLS Logging
+
+You can enable TLS debug logging at the JVM level by starting the bookies
and/or clients with `javax.net.debug` system property. For example:
+
+```shell
+-Djavax.net.debug=all
+```
+
+You can find more details on this in [Oracle
documentation](http://docs.oracle.com/javase/8/docs/technotes/guides/security/jsse/ReadDebug.html)
on
+[debugging SSL/TLS
connections](http://docs.oracle.com/javase/8/docs/technotes/guides/security/jsse/ReadDebug.html).
diff --git a/site/docs/4.5.0/security/zookeeper.md
b/site/docs/4.5.0/security/zookeeper.md
new file mode 100644
index 0000000..e16be69
--- /dev/null
+++ b/site/docs/4.5.0/security/zookeeper.md
@@ -0,0 +1,41 @@
+---
+title: ZooKeeper Authentication
+prev: ../sasl
+---
+
+## New Clusters
+
+To enable `ZooKeeper` authentication on Bookies or Clients, there are two
necessary steps:
+
+1. Create a `JAAS` login file and set the appropriate system property to point
to it as described in [GSSAPI (Kerberos)](../sasl#notes).
+2. Set the configuration property `zkEnableSecurity` in each bookie to `true`.
+
+The metadata stored in `ZooKeeper` is such that only certain clients will be
able to modify and read the corresponding znodes.
+The rationale behind this decision is that the data stored in ZooKeeper is not
sensitive, but inappropriate manipulation of znodes can cause cluster
+disruption.
+
+## Migrating Clusters
+
+If you are running a version of BookKeeper that does not support security or
simply with security disabled, and you want to make the cluster secure,
+then you need to execute the following steps to enable ZooKeeper
authentication with minimal disruption to your operations.
+
+1. Perform a rolling restart setting the `JAAS` login file, which enables
bookie or clients to authenticate. At the end of the rolling restart,
+ bookies (or clients) are able to manipulate znodes with strict ACLs, but
they will not create znodes with those ACLs.
+2. Perform a second rolling restart of bookies, this time setting the
configuration parameter `zkEnableSecurity` to true, which enables the use
+ of secure ACLs when creating znodes.
+3. Currently we don't have provide a tool to set acls on old znodes. You are
recommended to set it manually using ZooKeeper tools.
+
+It is also possible to turn off authentication in a secured cluster. To do it,
follow these steps:
+
+1. Perform a rolling restart of bookies setting the `JAAS` login file, which
enable bookies to authenticate, but setting `zkEnableSecurity` to `false`.
+ At the end of rolling restart, bookies stop creating znodes with secure
ACLs, but are still able to authenticate and manipulate all znodes.
+2. You can use ZooKeeper tools to manually reset all ACLs under the znode set
in `zkLedgersRootPath`, which defaults to `/ledgers`.
+3. Perform a second rolling restart of bookies, this time omitting the system
property that sets the `JAAS` login file.
+
+## Migrating the ZooKeeper ensemble
+
+It is also necessary to enable authentication on the `ZooKeeper` ensemble. To
do it, we need to perform a rolling restart of the ensemble and
+set a few properties. Please refer to the ZooKeeper documentation for more
details.
+
+1. [Apache ZooKeeper
Documentation](http://zookeeper.apache.org/doc/r3.4.6/zookeeperProgrammers.html#sc_ZooKeeperAccessControl)
+2. [Apache ZooKeeper
Wiki](https://cwiki.apache.org/confluence/display/ZOOKEEPER/Zookeeper+and+SASL)
diff --git a/site/docs/latest/admin/bookies.md
b/site/docs/latest/admin/bookies.md
index d9c6959..f9b1dcf 100644
--- a/site/docs/latest/admin/bookies.md
+++ b/site/docs/latest/admin/bookies.md
@@ -177,4 +177,4 @@ If the change was the result of an accidental configuration
change, the change c
192.168.1.10:3181
```
- See the [AutoRecovery](../autorecovery) documentation for more info on the
re-replication process.
\ No newline at end of file
+ See the [AutoRecovery](../autorecovery) documentation for more info on the
re-replication process.
diff --git a/site/docs/latest/admin/metrics.md
b/site/docs/latest/admin/metrics.md
index e2595d6..635135f 100644
--- a/site/docs/latest/admin/metrics.md
+++ b/site/docs/latest/admin/metrics.md
@@ -38,4 +38,4 @@ To enable stats:
<!-- ## Enabling stats in the bookkeeper library
TODO
--->
\ No newline at end of file
+-->
diff --git a/site/docs/latest/deployment/manual.md
b/site/docs/latest/deployment/manual.md
index 654595f..daafd55 100644
--- a/site/docs/latest/deployment/manual.md
+++ b/site/docs/latest/deployment/manual.md
@@ -53,4 +53,4 @@ Once cluster metadata formatting has been completed, your
BookKeeper cluster is
## AutoRecovery
[this guide](../../admin/autorecovery)
--->
\ No newline at end of file
+-->
diff --git a/site/docs/latest/overview/overview.md
b/site/docs/latest/overview/overview.md
index e17bfaa..1c93193 100644
--- a/site/docs/latest/overview/overview.md
+++ b/site/docs/latest/overview/overview.md
@@ -1,5 +1,5 @@
---
-title: Apache BookKeeper 4.5.0-SNAPSHOT Documentation
+title: Apache BookKeeper 4.6.0-SNAPSHOT Documentation
---
<!--
Licensed to the Apache Software Foundation (ASF) under one
diff --git a/site/docs/latest/overview/releaseNotes.md
b/site/docs/latest/overview/releaseNotes.md
index 08bde01..668c5bc 100644
--- a/site/docs/latest/overview/releaseNotes.md
+++ b/site/docs/latest/overview/releaseNotes.md
@@ -1,5 +1,5 @@
---
-title: Apache BookKeeper 4.5.0-SNAPSHOT Release Notes
+title: Apache BookKeeper 4.6.0-SNAPSHOT Release Notes
---
Apache BookKeeper {{ site.latest_version }} is still under developement.
diff --git a/site/docs/latest/overview/releaseNotesTemplate.md
b/site/docs/latest/overview/releaseNotesTemplate.md
index 15822e6..7fcc5dc 100644
--- a/site/docs/latest/overview/releaseNotesTemplate.md
+++ b/site/docs/latest/overview/releaseNotesTemplate.md
@@ -1,5 +1,5 @@
---
-title: Apache BookKeeper 4.5.0-SNAPSHOT Release Notes
+title: Apache BookKeeper 4.6.0-SNAPSHOT Release Notes
---
[provide a summary of this release]
diff --git a/site/docs/latest/reference/config.md
b/site/docs/latest/reference/config.md
index 6a420d0..8997b6b 100644
--- a/site/docs/latest/reference/config.md
+++ b/site/docs/latest/reference/config.md
@@ -6,4 +6,4 @@ subtitle: A reference guide to all of BookKeeper's configurable
parameters
The table below lists parameters that you can set to configure {% pop bookies
%}. All configuration takes place in the `bk_server.conf` file in the
`bookkeeper-server/conf` directory of your [BookKeeper
installation](../../getting-started/installing).
-{% include config.html id="bk_server" %}
\ No newline at end of file
+{% include config.html id="bk_server" %}
diff --git a/site/releases.md b/site/releases.md
index c54419c..7680f19 100644
--- a/site/releases.md
+++ b/site/releases.md
@@ -27,6 +27,10 @@ Client Guide | API docs
## News
+### [date] Release 4.5.0 available
+
+[INSERT SUMMARY]
+
### 16 May, 2016: release 4.4.0 available
This is the fourth release of BookKeeper as an Apache Top Level Project!
--
To stop receiving notification emails like this one, please contact
['"commits@bookkeeper.apache.org" <commits@bookkeeper.apache.org>'].
