Set the total off-heap memory size to be used by HBase to the environment variable HBASE_OFFHEAPSIZE. One way to do this is to set it in hbase-env.sh
Note The “G” is for gigabytes. The value for x should be 1 to 2 GB and the value should be at the higher end for clusters handling high volume of transactions.
- The other option to configure the total off-heap memory size is tp set the -XX:MaxDirectMemorySize JVM property. Again this value can be set in hbase-env.sh
If you are wondering what x GB is for, it is for Java direct memory used by hdfs client used by hbase to interact with the underlying hdfs filesystem.
- Set the HBase property hbase.bucketcache.combinedcache.enabled to true so that on-heap cache will be used for index and bloomfilter blocks along with bucketcache for data blocks.