Hi, I am running HBase 0.94.6 (cdh-4.4.0) with 25 region servers. I am testing a scenario to read and write only from/to RAM.
I have the following settings Table precreated with 25 regions. HFile size - 48 GB MemStore size - 72 GB Heap size - 96 GB These settings are to avoid any flushes to the disk. Data need not be persisted. I am able to achieve a load throughput of 75K ops per region server. While reading 23 region servers are serving requests with throughput of 55K ops, but randomly 2 of the region servers always end up serving few 100 ops. In these 2 region servers the CPU usage is very high and close to 100% continuously bringing down the overall throughput. I did not observe any long GC pauses in this time. I also tried applying the patch for HBASE-9428 issue, but still faced the same problem. Thread dump for the affected region server is at http://pastebin.com/JGx9gXnm Any hints on how to solve this.? Thanks and regards Vinay S Kashyap
