Recently Mark Callaghan blogged about using O_DIRECT for the InnoDB transaction log. He
noted that there was not a significant performance gain if the
number of concurrent connections increases. I've done my share of
testing and retesting over the past months to determine how
useful this is. Based on a small TPCC workload (100 warehouses,
64 connections, 1 hour test, 5 minute rampup), I've seen huge
performance gains by setting ALL_O_DIRECT for the variable
innodb_flush_method using Percona XtraDB.
Without using Direct I/O, the benchmark generated a TpmC score of
approximately 24,500 (HP DL160 G6, 2 x Xeon E5620 2.40GHz, 16GB
mem, 4x300 GB SAS, RAID-10). After setting the variable to
ALL_O_DIRECT, TpmC score went up to 48,000. Huge increase. This
deserves some more investigation and some more testing. I want to
also try this out on some older …
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Jun
28
2011
Showing entries 1 to 1