Hi All,   Thanks for your help. Heap memory was not sized as per recommendation given in below link and we had increased the memory and restarted the Hive metastore server which also did not help.   http://www.cloudera.com/documentation/enterprise/latest/topics/cdh_ig_hiveserver2_configure.html   Looks like there were some process which was holding/blocking memory and we had to restart the Complete cluster to resolve this problem.   Thank you once again for input.   Regards, Ajay chaudhary     ... View more

I'm afraid there's no easy way to recover out of this if you've not taken HDFS snapshots prior to this either. If you've stopped the entire cluster immediately to prevent further disk usage, you can perhaps try to run ext-level disk recovery tools to recover the deleted blocks, and then rollback your NN to start from the pre-deletes checkpoint, and that may give back some fraction of your data. ... View more

As Harsh suggested, for a new (empty) table without any 'split' defined, the number of reducers will always be 1. If you pre-split the table before import, you'd get that many number of reducers (Of course pre-splitting needs a good idea of how your row keys are designed and is broad topic in itself. See HBase The Definitive Guide > Chapter 11 > Optimizing Splits and Compactions >Presplitting Regions )   Example: When the table is pre-splitted with 6 regions: hbase(main):002:0>create 'hly_temp2', {NAME => 't', VERSIONS => 1}, {SPLITS => ['USW000138290206', 'USW000149290623', 'USW000231870807', 'USW000242331116', 'USW000937411119']} # hadoop jar /usr/lib/hbase/hbase-server.jar importtsv -Dimporttsv.bulk.output=/user/hac/output/2-4 -Dimporttsv.columns=HBASE_ROW_KEY,t:v01 hly_temp2 /user/hac/input/2-1 ... .... Job Counters Launched map tasks=1 Launched reduce tasks=6 <<< ... View more

If you've previously set manual overrides to MaxPermSize options in your configurations, you can remove them away safely having switched to using JDK8. If you still have parts that use JDK7, leave them be and ignore the warning. The warnings themselves do not pose a problem, as JDK8 will simply note that it won't be using them anymore and continue to start up normally. However, a future Java version (JDK9 or 10) may choose to interpret it as an invalid command and fail. Read more on this JDK level change at https://dzone.com/articles/java-8-permgen-metaspace ... View more