Author: buildbot
Date: Thu Aug 14 19:20:42 2014
New Revision: 919361
Log:
Production update by buildbot for activemq
Modified:
websites/production/activemq/content/cache/main.pageCache
websites/production/activemq/content/leveldb-store.html
Modified: websites/production/activemq/content/cache/main.pageCache
==============================================================================
Binary files - no diff available.
Modified: websites/production/activemq/content/leveldb-store.html
==============================================================================
--- websites/production/activemq/content/leveldb-store.html (original)
+++ websites/production/activemq/content/leveldb-store.html Thu Aug 14 19:20:42
2014
@@ -85,26 +85,11 @@
<p class="title">Version Compatibility</p>
<span class="aui-icon icon-hint">Icon</span>
<div class="message-content">
-
-<p>Available in ActiveMQ 5.8.0 and newer </p>
+ <p>Available in ActiveMQ 5.8.0 and newer</p>
</div>
</div>
-
-
-<p>The LevelDB Store is a file based persistence database that is local to the
message broker that is using it. It has been optimized to provide even faster
persistence than KahaDB. It's similar to KahahDB but instead of using a custom
B-Tree implementation to index the write ahead logs, it uses <a shape="rect"
class="external-link" href="https://code.google.com/p/leveldb/";
rel="nofollow">LevelDB</a> based indexes which have several nice properties due
to the 'append only' files access patterns : </p>
-
-<ul><li>Fast updates (No need to do random disk updates)</li><li>Concurrent
reads</li><li>Fast index snapshots using hard links</li></ul>
-
-
-<p>Both KahaDB and the LevelDB store have to do periodic garbage collection
cycles to determine which log files can deleted. In the case of KahaDB, this
can be quite expensive as you increase the amount of data stored and can cause
read/write stalls while the collection occurs. The LevelDB store uses a much
cheaper algorithm to determine when log files can be collected and avoids those
stalls.</p>
-
-<h2 id="LevelDBStore-Configuration">Configuration</h2>
-
-<p>You can configure ActiveMQ to use LevelDB for its persistence adapter -
like below :</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false"
type="syntaxhighlighter"><![CDATA[
- <broker brokerName="broker" ... >
+<p>The LevelDB Store is a file based persistence database that is local to the
message broker that is using it. It has been optimized to provide even faster
persistence than KahaDB. It's similar to KahahDB but instead of using a custom
B-Tree implementation to index the write ahead logs, it uses <a shape="rect"
class="external-link" href="https://code.google.com/p/leveldb/";
rel="nofollow">LevelDB</a> based indexes which have several nice properties due
to the 'append only' files access patterns :</p><ul><li>Fast updates (No need
to do random disk updates)</li><li>Concurrent reads</li><li>Fast index
snapshots using hard links</li></ul><p>Both KahaDB and the LevelDB store have
to do periodic garbage collection cycles to determine which log files can
deleted. In the case of KahaDB, this can be quite expensive as you increase the
amount of data stored and can cause read/write stalls while the collection
occurs. The LevelDB store uses a much cheaper algorithm to determine when log
files
can be collected and avoids those stalls.</p><h2
id="LevelDBStore-Configuration">Configuration</h2><p>You can configure ActiveMQ
to use LevelDB for its persistence adapter - like below :</p><div class="code
panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false"
type="syntaxhighlighter"><![CDATA[ <broker brokerName="broker"
... >
...
<persistenceAdapter>
<levelDB directory="activemq-data"/>
@@ -112,18 +97,7 @@
...
</broker>
]]></script>
-</div></div>
-
-<h3 id="LevelDBStore-LevelDBProperties">LevelDB Properties</h3>
-
-<div class="table-wrap"><table class="confluenceTable"><tbody><tr><th
colspan="1" rowspan="1" class="confluenceTh"><p> property name </p></th><th
colspan="1" rowspan="1" class="confluenceTh"><p> default value </p></th><th
colspan="1" rowspan="1" class="confluenceTh"><p> Comments </p></th></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> directory </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> "LevelDB" </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> The directory which the store
will use to hold it's data files. The store will create the directory if it
does not already exist. </p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p> readThreads </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> 10 </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> The number of concurrent IO read threads to allowed.
</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p> sync
</p></td><td colspan="1" rowspan=
"1" class="confluenceTd"><p> true </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> If set to false, then the store does not sync logging
operations to disk </p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p> logSize </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> 104857600 (100 MB) </p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p> The max size (in bytes) of each data log
file before log file rotation occurs. </p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p> logWriteBufferSize </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> 4194304 (4 MB) </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> That maximum amount of log
data to build up before writing to the file system. </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> verifyChecksums </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> false </p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p> Se
t to true to force checksum verification of all data that is read from the
file system. </p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p> paranoidChecks </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> false </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> Make the store error out as soon as possible if it
detects internal corruption. </p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p> indexFactory </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> org.fusesource.leveldbjni.JniDBFactory,
org.iq80.leveldb.impl.Iq80DBFactory </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> The factory classes to use when creating the LevelDB
indexes </p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>
indexMaxOpenFiles </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>
1000 </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Number of
open files that can be used by the index
. </p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>
indexBlockRestartInterval </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> 16 </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> Number keys between restart points for delta encoding
of keys. </p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>
indexWriteBufferSize </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> 6291456 (6 MB) </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> Amount of index data to build up in memory before
converting to a sorted on-disk file. </p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p> indexBlockSize </p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p> 4096 (4 K) </p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p> The size of index data packed per block.
</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>
indexCacheSize </p></td><td colspan="1" rowspan="1" class
="confluenceTd"><p> 268435456 (256 MB) </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> The maximum amount of off-heap memory to use to cache
index blocks. </p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p> indexCompression </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> snappy </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> The type of compression to apply to the index blocks.
Can be snappy or none. </p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p> logCompression </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> none </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> The type of compression to apply to the log records.
Can be snappy or none. </p></td></tr></tbody></table></div>
-
-
-<p>For tuning locking properties please take a look at <a shape="rect"
href="pluggable-storage-lockers.html">Pluggable storage lockers</a></p>
-
-<h2 id="LevelDBStore-AlsoSee">Also See</h2>
-
-<ul><li><a shape="rect" href="replicated-leveldb-store.html">Replicated
LevelDB Store</a> An extended version of this store which self replicates to
other broker nodes to increase message availability.</li></ul></div>
+</div></div><h3 id="LevelDBStore-LevelDBProperties">LevelDB
Properties</h3><div class="table-wrap"><table
class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1"
class="confluenceTh"><p>property name</p></th><th colspan="1" rowspan="1"
class="confluenceTh"><p>default value</p></th><th colspan="1" rowspan="1"
class="confluenceTh"><p>Comments</p></th></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>directory</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>"LevelDB"</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>The directory which the store will use to hold it's
data files. The store will create the directory if it does not already
exist.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>sync</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>true</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>If set to false, then the store does not sync logging
operations to disk</p></td></tr><tr><td colspan="1" row
span="1" class="confluenceTd"><p>logSize</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>104857600 (100 MB)</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>The max size (in bytes) of each data log file before
log file rotation occurs.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>logWriteBufferSize</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>4194304 (4 MB)</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>That maximum amount of log data to build up before
writing to the file system.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>verifyChecksums</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>false</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Set to true to force checksum verification of all data
that is read from the file system.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>paranoidChecks</p></td><td colspan="1" rowspan="1"
class="confluen
ceTd"><p>false</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Make the store error out as soon as possible if it
detects internal corruption.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>indexFactory</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>org.fusesource.leveldbjni.JniDBFactory,
org.iq80.leveldb.impl.Iq80DBFactory</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>The factory classes to use when creating the LevelDB
indexes</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>indexMaxOpenFiles</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>1000</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Number of open files that can be used by the
index.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>indexBlockRestartInterval</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>16</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Number keys between r
estart points for delta encoding of keys.</p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p>indexWriteBufferSize</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>6291456 (6 MB)</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Amount of index data to build
up in memory before converting to a sorted on-disk file.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>indexBlockSize</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>4096 (4 K)</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>The size of index data packed
per block.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>indexCacheSize</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>268435456 (256 MB)</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>The maximum amount of off-heap memory to use to cache
index blocks.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>indexCompression</p></td><t
d colspan="1" rowspan="1" class="confluenceTd"><p>snappy</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>The type of compression to
apply to the index blocks. Can be snappy or none.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>logCompression</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>none</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>The type of compression to apply to the log
records. Can be snappy or none.</p></td></tr></tbody></table></div><p>For
tuning locking properties please take a look at <a shape="rect"
href="pluggable-storage-lockers.html">Pluggable storage lockers</a></p><h2
id="LevelDBStore-AlsoSee">Also See</h2><ul><li><a shape="rect"
href="replicated-leveldb-store.html">Replicated LevelDB Store</a> An extended
version of this store which self replicates to other broker nodes to increase
message availability.</li></ul></div>
</td>
<td valign="top">
<div class="navigation">
