Index: src/docbkx/book.xml =================================================================== --- src/docbkx/book.xml (revision 1147261) +++ src/docbkx/book.xml (working copy) @@ -1550,38 +1550,21 @@ Runtime - Loading, why do I see pauses when loading HBase? - - - - If compression is enabled, see this thread up on the user list, - Long client pauses with compression. - - - - - - Why does my RegionServer hang inexplicitly? + I'm having problems with my HBase cluster, how can I troubleshoot it? - Are you running an old JVM (< 1.6.0_u21?)? When you look at a thread dump, - does it look like threads are BLOCKED but no one holds the lock all are - blocked on? See HBASE 3622 Deadlock in HBaseServer (JVM bug?). - Adding -XX:+UseMembar to the HBase HBASE_OPTS in conf/hbase-env.sh - may fix it. + See . - Why do I see double the actual count of regionservers, once by domain name and then by IP? + How can I improve HBase cluster performance? - Fix your DNS. In versions of HBase before 0.92.x, reverse DNS needs to give same answer - as forward lookup. See HBASE 3431 - Regionserver is not using the name given it by the master; double entry in master listing of servers for gorey details. + See . Index: src/docbkx/troubleshooting.xml =================================================================== --- src/docbkx/troubleshooting.xml (revision 1146748) +++ src/docbkx/troubleshooting.xml (working copy) @@ -455,6 +455,9 @@ more data is packed into the same region, but performance is achieved by being able to write larger files - which is why HBase waits until the flushize before writing a new StoreFile. And smaller StoreFiles become targets for compaction. Without compression the files are much bigger and don't need as much compaction, however this is at the expense of I/O. + + For additional information, see this thread on Long client pauses with compression. + @@ -545,7 +548,17 @@
Runtime Errors - + +
+ RegionServer Hanging + + Are you running an old JVM (< 1.6.0_u21?)? When you look at a thread dump, + does it look like threads are BLOCKED but no one holds the lock all are + blocked on? See HBASE 3622 Deadlock in HBaseServer (JVM bug?). + Adding -XX:+UseMembar to the HBase HBASE_OPTS in conf/hbase-env.sh + may fix it. + +
java.io.IOException...(Too many open files) @@ -649,6 +662,14 @@ and then the client goes back to .META. to find the new location of the moved region. However, if the NotServingRegionException is logged ERROR, then the client ran out of retries and something probably wrong.
+
+ Regions listed by domain name, then IP + + Fix your DNS. In versions of HBase before 0.92.x, reverse DNS needs to give same answer + as forward lookup. See HBASE 3431 + RegionServer is not using the name given it by the master; double entry in master listing of servers for gorey details. + +