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Subject svn commit: r940389 - in /websites/staging/accumulo/trunk/content: ./ release_notes/1.6.2.html
Date Mon, 16 Feb 2015 20:05:56 GMT
Author: buildbot
Date: Mon Feb 16 20:05:56 2015
New Revision: 940389

Staging update by buildbot for accumulo

    websites/staging/accumulo/trunk/content/   (props changed)

Propchange: websites/staging/accumulo/trunk/content/
--- cms:source-revision (original)
+++ cms:source-revision Mon Feb 16 20:05:56 2015
@@ -1 +1 @@

Modified: websites/staging/accumulo/trunk/content/release_notes/1.6.2.html
--- websites/staging/accumulo/trunk/content/release_notes/1.6.2.html (original)
+++ websites/staging/accumulo/trunk/content/release_notes/1.6.2.html Mon Feb 16 20:05:56 2015
@@ -194,113 +194,27 @@ Latest 1.5 release: <strong>1.5.2</stron
     <h1 class="title">Apache Accumulo 1.6.1 Release Notes</h1>
-    <p>Apache Accumulo 1.6.1 is a maintenance release on the 1.6 version branch.
-This release contains changes from over 175 issues, comprised of bug-fixes, performance
-improvements and better test cases. As this is a maintenance release, Apache Accumulo
-1.6.1 has no client API  incompatibilities over Apache Accumulo 1.6.0. Users of 1.6.0
-are strongly encouraged to update as soon as possible to benefit from the improvements.</p>
-<p>New users are encouraged to use this release over 1.6.0 or any other older releases.
-information about improvements since Accumulo 1.5, see the <a href="/release_notes/1.6.0.html">1.6.0
release notes</a>.</p>
+    <p>Apache Accumulo 1.6.2 is a maintenance release on the 1.6 version branch.
+This release contains changes from over 150 issues, comprised of bug-fixes, performance
+improvements and better test cases. Apache Accumulo 1.6.2 is the first release since the
+community has adopted <a href="">Semantic Versioning</a> which
means that all changes to the <a href="">public
+are guaranteed to be made without adding to or removing from the public API. This ensures
+that client code that runs against 1.6.1 is guaranteed to run against 1.6.2 and vice versa.</p>
+<p>Users of 1.6.0 or 1.6.1 are strongly encouraged to update as soon as possible to
benefit from
+the improvements with very little concern in change of underlying functionality. For
+information about improvements since Accumulo 1.5, see the <a href="">1.6.0</a>
and <a href="">1.6.1</a> release
 <h2 id="performance-improvements">Performance Improvements</h2>
 <p>Apache Accumulo 1.6.1 includes a number of performance-related fixes over previous
 Many of these improvements were also included in the recently released Apache Accumulo 1.5.2.</p>
-<h3 id="write-ahead-log-sync-performance">Write-Ahead Log sync performance</h3>
-<p>The Write-Ahead Log (WAL) files are used to ensure durability of updates made to
-A sync is called on the file in HDFS to make sure that the changes to the WAL are persisted
-to disk, which allows Accumulo to recover in the case of failure. <a href="">ACCUMULO-2766</a>
-an issue where an operation against a WAL would unnecessarily wait for multiple syncs, slowing
-down the ingest on the system.</p>
-<h3 id="minor-compactions-not-aggressive-enough">Minor-Compactions not aggressive enough</h3>
-<p>On a system with ample memory provided to Accumulo, long hold-times were observed
-blocks the ingest of new updates. Trying to free more server-side memory by running minor
-compactions more frequently increased the overall throughput on the node. These changes
-were made in <a href="">ACCUMULO-2905</a>.</p>
-<h3 id="heapiterator-optimization">HeapIterator optimization</h3>
-<p>Iterators, a notable feature of Accumulo, are provided to users as a server-side
-construct, but are also used internally for numerous server operations. One of these system
-is the HeapIterator which implements a PriorityQueue of other Iterators. One way this iterator
-used is to merge multiple files in HDFS to present a single, sorted stream of Key-Value pairs.
<a href="">ACCUMULO-2827</a>
-introduces a performance optimization to the HeapIterator which can improve the speed of
-HeapIterator in common cases.</p>
-<h3 id="write-ahead-log-sync-implementation">Write-Ahead log sync implementation</h3>
-<p>In Hadoop-2, two implementations of sync are provided: hflush and hsync. Both of
-methods provide a way to request that the datanodes write the data to the underlying
-medium and not just hold it in memory (the <em>fsync</em> syscall). While both
of these methods
-inform the Datanodes to sync the relevant block(s), <em>hflush</em> does not
wait for acknowledgement
-from the Datanodes that the sync finished, where <em>hsync</em> does. To provide
the most reliable system
-"out of the box", Accumulo defaults to <em>hsync</em> so that your data is as
secure as possible in 
-a variety of situations (notably, unexpected power outages).</p>
-<p>The downside is that performance tends to suffer because waiting for a sync to disk
is a very
-expensive operation. <a href="">ACCUMULO-2842</a>
introduces a new system property, tserver.wal.sync.method,
-that lets users to change the HDFS sync implementation from <em>hsync</em> to
<em>hflush</em>. Using <em>hflush</em> instead
-of <em>hsync</em> may result in about a 30% increase in ingest performance.</p>
-<p>For users upgrading from Hadoop-1 or Hadoop-0.20 releases, <em>hflush</em>
is the equivalent of how
-sync was implemented in these older versions of Hadoop and should give comparable performance.</p>
+<h3 id="improvement-1">Improvement 1</h3>
+<h3 id="improvement-2">Improvement 2</h3>
 <h2 id="other-improvements">Other improvements</h2>
-<h3 id="use-of-hadoop-credentialproviders">Use of Hadoop CredentialProviders</h3>
-<p>Apache Hadoop 2.6.0 introduced a new API aimed at providing ways to separate sensitive
-from being stored in plaintext as a part of <a href="">HADOOP-10607</a>.
Accumulo has had two sensitive
-configuration properties stored in <em>accumulo-site.xml</em> for every standard
installation: instance.secret
-and If either of these properties are compromised, it could
lead to
-unwanted access of Accumulo. <a href="">ACCUMULO-2464</a>
modifies Accumulo so that it can stored any sensitive
-configuration properties in a Hadoop CredentialProvider. With sensitive values removed from
-it can be shared without concern and security can be focused solely on the CredentialProvider.</p>
+<h3 id="improvement-1_1">Improvement 1</h3>
 <h2 id="notable-bug-fixes">Notable Bug Fixes</h2>
-<h3 id="add-configurable-maximum-frame-size-to-thrift-proxy">Add configurable maximum
frame size to Thrift proxy</h3>
-<p>The Thrift proxy server was subject to memory exhaustion, typically
-due to bad input, where the server would attempt to allocate a very large
-buffer and die in the process. <a href="">ACCUMULO-2658</a>
introduces a configuration
-parameter, like <a href="">ACCUMULO-2360</a>,
to prevent this error.</p>
-<h3 id="offline-tables-can-prevent-tablet-balancing">Offline tables can prevent tablet
-<p>Before 1.6.1, when a table with many tablets was created, ingested into, and
-taken offline, tablet balancing may have stoppped. This would happen if there
-were tablet migrations for the table, because the migrations couldn't occur.
-The balancer will not run when there are outstanding migrations; therefore, a
-system could become unbalanced. <a href="">ACCUMULO-2694</a>
introduces a fix to ensure
-that offline tables do not block balancing and improves the server-side
-<h3 id="miniaccumulocluster-process-management">MiniAccumuloCluster process management</h3>
-<p>MiniAccumuloCluster had a few issues which could cause deadlock or a method that
-never returns. Most of these are related to management of the Accumulo processes
-(<a href="">ACCUMULO-2764</a>,
<a href="">ACCUMULO-2985</a>,
and <a href="">ACCUMULO-3055</a>).</p>
-<h3 id="iteratorsettings-not-correctly-serialized-in-rangeinputsplit">IteratorSettings
not correctly serialized in RangeInputSplit</h3>
-<p>The Writable interface methods on the RangeInputSplit class accidentally omitted
-calls to serialize the IteratorSettings configured for the Job. <a href="">ACCUMULO-2962</a>
-fixes the serialization and adds some additional tests.</p>
-<h3 id="constraint-violation-causes-hung-scans">Constraint violation causes hung scans</h3>
-<p>A failed bulk import transaction had the ability to create an infinitely retrying
-loop due to a constraint violation. This directly prevents scans from completing,
-but will also hang compactions. <a href="">ACCUMULO-3096</a>
fixes the issue so that the
-constraint no longer hangs the entire system.</p>
-<h3 id="unable-to-upgrade-cleanly-from-15">Unable to upgrade cleanly from 1.5</h3>
-<p>When upgrading a table from 1.5.1 to 1.6.0, a user experienced an error where the
-never came online. <a href="">ACCUMULO-2974</a>
fixes an issue from the change of file references
-stored as absolute paths instead of relative paths in the Accumulo metadata table.</p>
-<h3 id="guava-dependency-changed">Guava dependency changed</h3>
-<p><a href="">ACCUMULO-3100</a>
lowered the dependency on Guava from 15.0 to 14.0.1. This dependency
-now matches what Hadoop is depending on for the 2.x.y version line. Depending on a newer
-version of Guava introduces many issues stemming from deprecated classes in use by Hadoop
-which have been removed. While installations of Accumulo will likely work as expected with
-newer versions of Guava on the classpath (because the Hadoop processes will have their own
-classpath), use of MiniDfsClusters with the new Guava version will result in errors.</p>
-<p>Users can attempt to use a newer version of Guava on the Accumulo server classpath;
-the success is dependent on Hadoop client libraries not using (missing) Guava methods internally.</p>
-<h3 id="scanners-eat-interruptedexception">Scanners eat InterruptedException</h3>
-<p>Scanners previously consumed InterruptedExceptions and did not exit after. In multi-threaded
-environments, this is very problematic as there is no means to stop the Scanner from reading
-<a href="">ACCUMULO-3030</a>
fixes the Scanner so that interrupts are observed and the Scanner exits as expected.</p>
+<h3 id="bug-fix-1">Bug fix 1</h3>
+<h3 id="bug-fix-2">Bug fix 2</h3>
 <h2 id="documentation">Documentation</h2>
 <p>The following documentation updates were made: </p>
-<li><a href="">ACCUMULO-2767</a></li>
-<li><a href="">ACCUMULO-2796</a></li>
-<li><a href="">ACCUMULO-2919</a></li>
-<li><a href="">ACCUMULO-3008</a></li>
-<li><a href="">ACCUMULO-2874</a></li>
-<li><a href="">ACCUMULO-2821</a></li>
-<li><a href="">ACCUMULO-3097</a></li>
-<li><a href="">ACCUMULO-3097</a></li>
 <h2 id="testing">Testing</h2>
 <p>Each unit and functional test only runs on a single node, while the RandomWalk and
Continuous Ingest tests run 
 on any number of nodes. <em>Agitation</em> refers to randomly restarting Accumulo
processes and Hadoop Datanode processes,
@@ -316,19 +230,19 @@ and, in HDFS High-Availability instances
-    <td>Apache 2.6.0-SNAPSHOT</td>
-    <td>2</td>
-    <td>Apache 3.4.5</td>
+    <td>N/A</td>
+    <td>1</td>
+    <td>N/A</td>
-    <td>Unit and Functional Tests, ContinuousIngest w/ verification (2B entries)</td>
+    <td>Unit and Integration Tests</td>
     <td>CentOS 6</td>
-    <td>Apache 2.3.0</td>
+    <td>Keith TBD</td>
-    <td>Apache 3.4.5</td>
+    <td>Keith TBD</td>
-    <td>24/hr RandomWalk, ContinuousIngest w/ verification w/ and w/o agitation (17B
entries), 24hr Randomwalk test</td>
+    <td>(Keith Verify this) ContinuousIngest w/ verification w/ and w/o agitation (31B
and 21B entries, respectively)</td>

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