svn commit: r1588315 - /accumulo/site/trunk/content/release_notes/1.6.0.mdtext

[kt...@apache.org]

Author: kturner
Date: Thu Apr 17 17:41:34 2014
New Revision: 1588315

URL: http://svn.apache.org/r1588315
Log:
ACCUMULO-2396 added ACCUMULO-2388 to release notes

Modified:
    accumulo/site/trunk/content/release_notes/1.6.0.mdtext

Modified: accumulo/site/trunk/content/release_notes/1.6.0.mdtext
URL: http://svn.apache.org/viewvc/accumulo/site/trunk/content/release_notes/1.6.0.mdtext?rev=1588315&r1=1588314&r2=1588315&view=diff
==============================================================================
--- accumulo/site/trunk/content/release_notes/1.6.0.mdtext (original)
+++ accumulo/site/trunk/content/release_notes/1.6.0.mdtext Thu Apr 17 17:41:34 2014
@@ -132,6 +132,8 @@ Be aware that you will need a C++ compil
 
 ## Known Issues
 
+### Slower writes than previous Accumulo versions
+
 When using Accumulo 1.6 and Hadoop 2, Accumulo will call hsync() on HDFS.
 Calling hsync improves durability by ensuring data is on disk (where other older 
 Hadoop versions might lose data in the face of power failure); however, calling
@@ -145,6 +147,17 @@ mutation queues.
 
 For more information, see [ACCUMULO-1950][ACCUMULO-1950] and [this comment][ACCUMULO-1905-comment].
 
+Another possible cause of slower writes is the change in write ahead log replication 
+between 1.4 and 1.5.  Accumulo 1.4. defaulted to two loggers servers.  Accumulo 1.5 and 1.6 store 
+write ahead logs in HDFS and default to using three datanodes.  
+
+### BatchWriter hold time error
+
+If a `BatchWriter` fails with `MutationsRejectedException` and the  message contains
+`"# server errors 1"` then it may be [ACCUMULO-2388][ACCUMULO-2388].  To confirm this look in the tablet server logs 
+for `org.apache.accumulo.tserver.HoldTimeoutException` around the time the `BatchWriter` failed.
+If this is happening often a possible work around is to set `general.rpc.timeout` to `240s`.    
+
 ### Other known issues
 
  * [ACCUMULO-1507][ACCUMULO-1507] Dynamic Classloader still can't keep proper track of jars
@@ -270,6 +283,7 @@ and, in HDFS High-Availability instances
 [ACCUMULO-2262]: https://issues.apache.org/jira/browse/ACCUMULO-2262 "Include java.net.preferIPv4Stack=true in process startup"
 [ACCUMULO-2334]: https://issues.apache.org/jira/browse/ACCUMULO-2334 "Lacking fallback when ACCUMULO_LOG_HOST isn't set"
 [ACCUMULO-2360]: https://issues.apache.org/jira/browse/ACCUMULO-2360 "Need a way to configure TNonblockingServer.maxReadBufferBytes to prevent OOMs"
+[ACCUMULO-2388]: https://issues.apache.org/jira/browse/ACCUMULO-2388
 [ACCUMULO-2408]: https://issues.apache.org/jira/browse/ACCUMULO-2408 "metadata table not assigned after root table is loaded"
 [ACCUMULO-2441]: https://issues.apache.org/jira/browse/ACCUMULO-2441 "Document internal state stored in RFile names"
 [ACCUMULO-2495]: https://issues.apache.org/jira/browse/ACCUMULO-2495 "OOM exception didn't bring down tserver"