You need https://issues.apache.org/jira/browse/HBASE-11678
Just make sure the setting for MaxDirectMemorySize is > your offheap bucketcache size and then some -- see blockcache section in refguide for more detail (it looks like you have it set properly in the above). Regards MaxDirectMemorySize relationship to bucketcache size, it is a little messy. hbase.bucketcache. percentage.in.combinedcache has actually been removed in later versions because it tended to confuse. See HBASE-11520 for why and how it works/worked. Come back with more questions if still not clear. St.Ack On Fri, Aug 29, 2014 at 2:04 PM, gabriela montiel < [email protected]> wrote: > Hello, > > We are working on performance tunning on HBase 0.98 CDH 5.1 using bucket > cache. We were able to set up the bucket cache configuration on all storage > nodes but we wanted to know further details on how the MaxDirectMemorySize > is related to the bucket cache size and the Java heap size. How does the > MaxDirectMemorySize affects performance in HBase? > > Our current configuration is the following: > > <property> > <name>hbase.bucketcache.ioengine</name> > <value>offheap</value> > <source>hbase-site.xml</source> > </property> > <property> > <name>hbase.bucketcache.percentage.in.combinedcache</name> > <value>0.8</value> > <source>hbase-site.xml</source> > </property> > <property> > <name>hbase.bucketcache.size</name> > <value>10000</value> > <source>hbase-site.xml</source> > </property> > > -XX:MaxDirectMemorySize=12g -XX:+UseParNewGC -XX:+UseConcMarkSweepGC > -XX:-CMSConcurrentMTEnabled -XX:CMSInitiatingOccupancyFraction=70 > -XX:+CMSParallelRemarkEnabled > Java Heap Size: 12G > > > Thanks, > > Gaby >
