Sorry for confusion. I meant that I am getting 6000 ops/sec throughput overall using 4 machine. That is 1500 ops/sec/regionserver on average.
I checked the ping response time between machines. It is approximately .09 ms. Assuming that WAL sync thread tries to sync with two other hdfs node sequentially, the row lock will be held for at least 0.18 ms, which will still give a very high throughput per regionserver even if only one thread is working and all other threads are blocked because of locking. It appears that bottleneck is then the hdfs disk flush. And, consequently, above mentioned schema are equivalent w.r.t. performance. However, I have a question regarding the default hdfs policy of not flushing every WAL sync. Are not people in industry afraid of data loss however small probability of this happening. Are anyone aware of any company who does not use the hdfs default policy and flush every WAL sync. Thanks Abhishek -- View this message in context: http://apache-hbase.679495.n3.nabble.com/hbase-row-locking-tp4064432p4064458.html Sent from the HBase User mailing list archive at Nabble.com.
