Hi All, I have setup HBase replication between two clusters containing 25 nodes each. The inter-data center network link has a capacity of 500 MBPS.
I have been running some tests to understand the speed of replication. I am observing that the replication speed does not go more than 5 MBPS. On reading up regarding the same, I understand that the speed of data transfer depends on OS level TCP socket read and write buffer sizes. Below are the OS level parameters that I see for the socket size # cat /proc/sys/net/ipv4/tcp_wmem 4096 (min) 16384 (default) 4194304 (max) # cat /proc/sys/net/ipv4/tcp_rmem 4096 (min) 87380 (default) 6291456 (max) The default write buffer size for sockets is 16KB and the read buffer size is around 85KB. There are suggestions [1] to set higher values for the default read and write buffers to fully utilize the link capacity. But I am not sure how to influence HBase to use higher values for the socket read/write buffers when it does replication. Any thoughts from the community on the same? Thanks Sreeram [1] http://www.onlamp.com/pub/a/onlamp/2005/11/17/tcp_tuning.html
