Author: buildbot
Date: Tue May 6 15:28:36 2014
New Revision: 908195
Log:
Staging update by buildbot for accumulo
Modified:
websites/staging/accumulo/trunk/content/ (props changed)
websites/staging/accumulo/trunk/content/release_notes/1.6.0.html
Propchange: websites/staging/accumulo/trunk/content/
------------------------------------------------------------------------------
--- cms:source-revision (original)
+++ cms:source-revision Tue May 6 15:28:36 2014
@@ -1 +1 @@
-1592773
+1592779
Modified: websites/staging/accumulo/trunk/content/release_notes/1.6.0.html
==============================================================================
--- websites/staging/accumulo/trunk/content/release_notes/1.6.0.html (original)
+++ websites/staging/accumulo/trunk/content/release_notes/1.6.0.html Tue May 6
15:28:36 2014
@@ -192,8 +192,7 @@ Latest 1.4 release: <strong>1.4.5</stron
<h1 class="title">Release Notes for Apache Accumulo 1.6.0</h1>
- <p><strong>DRAFT 1.6.0 RELEASE NOTES</strong></p>
-<p>Apache Accumulo 1.6.0 adds some major new features and fixes many bugs.
This release contains changes from 609 issues contributed by 36 contributors
and committers. </p>
+ <p>Apache Accumulo 1.6.0 adds some major new features and fixes many bugs.
This release contains changes from 609 issues contributed by 36 contributors
and committers. </p>
<p>Accumulo 1.6.0 runs on Hadoop 1, however Hadoop 2 with HA namenode is
recommended for production systems. In addition to HA, Hadoop 2 also offers
better data durability guarantees, in the case when nodes lose power, than
Hadoop 1.</p>
<h2 id="notable-improvements">Notable Improvements</h2>
<h3 id="multiple-volume-support">Multiple volume support</h3>
@@ -211,9 +210,9 @@ Latest 1.4 release: <strong>1.4.5</stron
<p>The only built in test that conditional mutations support are equality and
isNull. However, iterators can be configured on a conditional mutation to run
before these test. This makes it possible to implement any number of test such
as less than, greater than, contains, etc.</p>
<h3 id="encryption">Encryption</h3>
<p>Encryption is still an experimental feature, but much progress has been
made since 1.5.0. Support for encrypting rfiles and write ahead logs were
added in <a href="https://issues.apache.org/jira/browse/ACCUMULO-958";
title="Support pluggable encryption in walogs">ACCUMULO-958</a> and <a
href="https://issues.apache.org/jira/browse/ACCUMULO-980"; title="Support
pluggable codecs for RFile">ACCUMULO-980</a>. Support for encrypting data over
the wire using SSL was added in <a
href="https://issues.apache.org/jira/browse/ACCUMULO-1009"; title="Support
encryption over the wire">ACCUMULO-1009</a>.</p>
-<p>When a tablet server fails, its write ahead logs are sorted and stored in
HDFS. In 1.6.0, encrypting these sorted write ahead logs is not supported. <a
href="https://issues.apache.org/jira/browse/ACCUMULO-981"; title="support
pluggable encryption when recovering write-ahead logs">ACCUMULO-981</a>
addresses this issue. </p>
+<p>When a tablet server fails, its write ahead logs are sorted and stored in
HDFS. In 1.6.0, encrypting these sorted write ahead logs is not supported. <a
href="https://issues.apache.org/jira/browse/ACCUMULO-981"; title="support
pluggable encryption when recovering write-ahead logs">ACCUMULO-981</a> is open
to address this issue. </p>
<h3 id="pluggable-compaction-strategies">Pluggable compaction strategies</h3>
-<p>One of the key elements of the <a
href="http://research.google.com/archive/bigtable.html";>BigTable</a> design is
use of the <a
href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.44.2782&rep=rep1&type=pdf";>Log
Structured Merge Tree</a>. This entails sorting data in memory, writing out
sorted files, and then later merging multiple sorted files into a single file.
These automatic merges happen in the background and Accumulo decides when to
merge files based comparing relative sizes of files to a compaction ratio.
Adjusting the compaction ratio is the only way a user can control this process.
<a href="https://issues.apache.org/jira/browse/ACCUMULO-1451"; title="Make
Compaction triggers extensible">ACCUMULO-1451</a> introduces pluggable
compaction strategies which allow users to choose when and what files to
compact. <a href="https://issues.apache.org/jira/browse/ACCUMULO-1808";
title="Create compaction strategy that has size limit">ACCUMULO-1808</a> adds a
com
paction strategy the prevents compaction of files over a configurable size.</p>
+<p>One of the key elements of the <a
href="http://research.google.com/archive/bigtable.html";>BigTable</a> design is
use of the <a
href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.44.2782&rep=rep1&type=pdf";>Log
Structured Merge Tree</a>. This entails sorting data in memory, writing out
sorted files, and then later merging multiple sorted files into a single file.
These automatic merges happen in the background and Accumulo decides when to
merge files based comparing relative sizes of files to a compaction ratio.
Before 1.6.0 adjusting the compaction ratio was the only way a user could
control this process. <a
href="https://issues.apache.org/jira/browse/ACCUMULO-1451"; title="Make
Compaction triggers extensible">ACCUMULO-1451</a> introduces pluggable
compaction strategies which allow users to choose when and what files to
compact. <a href="https://issues.apache.org/jira/browse/ACCUMULO-1808";
title="Create compaction strategy that has size limit">ACCUMULO-180
8</a> adds a compaction strategy that prevents compaction of files over a
configurable size.</p>
<h3 id="lexicoders">Lexicoders</h3>
<p>Accumulo only sorts data lexicographically. Getting something like a pair
of (<em>String</em>,<em>Integer</em>) to sort correctly in Accumulo is tricky.
It's tricky because you only want to compare the integers if the strings are
equal. It's possible to make this sort properly in Accumulo if the data is
encoded properly, but can be difficult. To make this easier <a
href="https://issues.apache.org/jira/browse/ACCUMULO-1336"; title="Add
lexicoders from Typo to Accumulo">ACCUMULO-1336</a> added Lexicoders to the
Accumulo API. Lexicoders provide an easy way to serialize data so that it
sorts properly lexicographically. Below is a simple example.</p>
<div class="codehilite"><pre> <span class="n">PairLexicoder</span> <span
class="n">plex</span> <span class="p">=</span> <span class="n">new</span> <span
class="n">PairLexicoder</span><span class="p">(</span><span
class="n">new</span> <span class="n">StringLexicoder</span><span
class="p">(),</span> <span class="n">new</span> <span
class="n">IntegerLexicoder</span><span class="p">());</span>
@@ -230,7 +229,7 @@ Latest 1.4 release: <strong>1.4.5</stron
<h3 id="locality-groups-in-memory">Locality groups in memory</h3>
<p>In cases where a very small amount of data is stored in a locality group
one would expect fast scans over that locality group. However this was not
always the case because recently written data stored in memory was not
partitioned by locality group. Therefore if a table had 100GB of data in
memory and 1MB of that was in locality group A, then scanning A would have
required reading all 100GB. <a
href="https://issues.apache.org/jira/browse/ACCUMULO-112"; title="Partition data
in memory by locality group">ACCUMULO-112</a> changes this and partitions data
by locality group as its written.</p>
<h3 id="service-ip-addresses">Service IP addresses</h3>
-<p>Previous versions of Accumulo always used IP addresses internally. This
could be problematic in virtual machine environments where IP addresses change.
In <a href="https://issues.apache.org/jira/browse/ACCUMULO-1585"; title="Use
FQDN/verbatim data from config files">ACCUMULO-1585</a> this was changed, now
the accumulo uses the exact hostnames from its config files for internal
addressing. </p>
+<p>Previous versions of Accumulo always used IP addresses internally. This
could be problematic in virtual machine environments where IP addresses change.
In <a href="https://issues.apache.org/jira/browse/ACCUMULO-1585"; title="Use
FQDN/verbatim data from config files">ACCUMULO-1585</a> this was changed, now
Accumulo uses the exact hostnames from its config files for internal
addressing. </p>
<p>All Accumulo processes running on a cluster are locatable via zookeeper.
Therefore using well known ports is not really required. <a
href="https://issues.apache.org/jira/browse/ACCUMULO-1664"; title="Make all
processes able to use random ports">ACCUMULO-1664</a> makes it possible to for
all Accumulo processes to use random ports. This makes it easier to run
multiple Accumulo instances on a single node. </p>
<p>While Hadoop <a href="http://wiki.apache.org/hadoop/HadoopIPv6";>does not
support IPv6 networks</a>, attempting to run on a system that does not have
IPv6 completely disabled can cause strange failures. <a
href="https://issues.apache.org/jira/browse/ACCUMULO-2262"; title="Include
java.net.preferIPv4Stack=true in process startup">ACCUMULO-2262</a> invokes the
JVM-provided configuration parameter at process startup to prefer IPv4 over
IPv6.</p>
<h3 id="viewfs">ViewFS</h3>
