Dear List , We are having scalability issues with a high end hardware The hardware is CPU = 4 * opteron 6272 with 16 cores ie Total = 64 cores. RAM = 128 GB DDR3 Disk = High performance RAID10 with lots of 15K spindles and a working BBU Cache. normally the 1 min load average of the system remains between 0.5 to 1.0 . The problem is that sometimes there are spikes of load avg which jumps to > 50 very rapidly ( ie from 0.5 to 50 within 10 secs) and it remains there for sometime and slowly reduces to normal value. During such times of high load average we observe that there is no IO wait in system and even CPU is 50% idle. In any case the IO Wait always remains < 1.0 % and is mostly 0. Hence the load is not due to high I/O wait which was generally the case with our previous hardware. We are puzzled why the CPU and DISK I/O system are not being utilized fully and would seek lists' wisdom on that. We have setup sar to poll the system parameters every minute and the data of which is graphed with cacti. If required any of the system parameters or postgresql parameter can easily be put under cacti monitoring and can be graphed. The query load is mostly read only. It is also possible to replicate the problem with pg_bench to some extent . I choose -s = 100 and -t=10000 , the load does shoot but not that spectacularly as achieved by the real world usage. any help shall be greatly appreciated. just a thought, will it be a good idea to partition the host hardware to 4 equal virtual environments , ie 1 for master (r/w) and 3 slaves r/o and distribute the r/o load on the 3 slaves ? regds mallah -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
