I'm experimenting with upgrading to MySQL 5.6 and am experiencing an unexplained increase in disk I/O utilization. After discussing this with several people I'm publishing in the hope that someone has an enlightenment on this.
We have a few dozens servers in a normal replication topology. On this particular replication topology we've already evaluated that STATEMENT based replication is faster than ROW based replication, and so we use SBR. We have two different workloads on our slaves, applied by two different HAProxy groups, on three different data centres. Hardware-wise, servers of two groups use either Virident SSD cards or normal SAS spindle disks.
Our servers are I/O bound. A common query used by both workloads looks up data that does not necessarily have a hotspot, and is[Read more...]