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"
