Did you adjust the writebuffer to a larger size and/or turn off autoFlush for the Htable? I've found that both of those settings can have a profound impact on write performance. You might also look at adjusting the handler count for the regionservers which by default is pretty low. You should also confirm that your splits are effective in distributing the writes.
On 9/24/12 11:01 AM, "Naveen" <[email protected]> wrote: >Hi, > >I've come across the following issue for which I'm unable to deduce what >the >root-cause could be. > >Scenario: >I'm trying to dump data(8.3M+ records) from mysql into a hbase table using >multi-threading(25 threads dumping 10 puts/tuples at a time). > >Config: >hbase v 0.92.0 >hadoop v 1.0 >1 master + 4 slaves >table is pre-split > >Issue: >Getting a NPE because RPC call takes longer than timeout(default 60 sec). >I'm not worried about the NPE(it's been fixed in 0.92.1+ releases) but >about >what could be causing RPC call to timeout on arbitrary intervals. > >Custom printed log : pastebin.com/r85wv8Yt > >WARN [Thread-99255] (HConnectionManager.java:1587) - Failed all from >region=dump,a405cdd9-b5b7-4ec2-9f91-fea98d5cb656,1348331511473.77f13d455fd >63 >c601816759b6ed575e8., hostname=hdslave1.company.com, port=60020 >java.util.concurrent.ExecutionException: java.lang.RuntimeException: >java.lang.NullPointerException > at >java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:222) > at java.util.concurrent.FutureTask.get(FutureTask.java:83) > at >org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementatio >n. >processBatchCallback(HConnectionManager.java:1557) > at >org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementatio >n. >processBatch(HConnectionManager.java:1409) > at >org.apache.hadoop.hbase.client.HTable.flushCommits(HTable.java:900) > at org.apache.hadoop.hbase.client.HTable.doPut(HTable.java:777) > at org.apache.hadoop.hbase.client.HTable.put(HTable.java:760) > at >org.apache.hadoop.hbase.client.HTablePool$PooledHTable.put(HTablePool.java >:4 >02) > at coprocessor.dump.Dumper.run(Dumper.java:41) > at java.lang.Thread.run(Thread.java:662) > >Any help or insights are welcome. > >Warm Regards, >Naveen >
