From https://builds.apache.org/view/G-L/view/HBase/job/HBase-0.92/lastCompletedBuild/testReport/org.apache.hadoop.hbase.client/TestAdmin/testCheckHBaseAvailableClosesConnection/ :
Caused by: java.io.IOException: Too many open files at sun.nio.ch.IOUtil.initPipe(Native Method) at sun.nio.ch.EPollSelectorImpl.<init>(EPollSelectorImpl.java:49) at sun.nio.ch.EPollSelectorProvider.openSelector(EPollSelectorProvider.java:18) This should be the cause - please increase open file count limit: [HBase-0.92] $ /bin/bash -xe /tmp/hudson4869495989888249427.sh + uname -a Linux hemera 2.6.32-32-server #62-Ubuntu SMP Wed Apr 20 22:07:43 UTC 2011 x86_64 GNU/Linux [HBase-0.92] $ /bin/bash -xe /tmp/hudson3283427105323421769.sh + ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 193125 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 Thanks