> -----Mensaje original----- > De: Shiva Raman > Enviado el: Martes, 22 de Septiembre de 2009 10:55 > Para: pgsql-performance@xxxxxxxxxxxxxx > Asunto: High CPU load on Postgres Server during > Peak times!!!! > > Dear all > > I am having a problem of high cpu loads in my postgres > server during peak time. Some quick advice: > > clusternode2:~ # rpm -qa | grep postgres > postgresql-devel-8.1.9-1.2 > postgresql-8.1.9-1.2 > postgresql-docs-8.1.9-1.2 > postgresql-server-8.1.9-1.2 > postgresql-libs-64bit-8.1.9-1.2 > postgresql-libs-8.1.9-1.2 > postgresql-jdbc-8.1-12.2 > postgresql-contrib-8.1.9-1.2 > > 8.1 is quite old. Consider upgrading as newer versions are faster. Current Postgres version is 8.4. > > High Availability Cluster with two IBM P Series Server and > one DS4700 Storage > > IBM P series P52A with 2-core 2.1 Ghz POWER5+ Processor Card > , 36 MB L3 Cache ,16 GB of RAM, > 73.4 GB 10,000 RPM Ultra320 SCSI Drive for Operating System . > Sounds you are underpowered on cpu for 500 concurrent users. Of course this really depends on what they are doing. > > IBM SAN DS4700 Storage with Fibre Channel HDD (73.4 GB * 10) > Two Partitions - 73.4 GB * 3 RAID 5 - 134 GB storage > partitions (One holding Jakarata tomcat > application server and other holding Postgresql Database) . > Four Hard disk RAID 5 with ext3 file systems hold the pgdata on SAN . > Hard disk rotational speed is 73 GB 15K IBM 2 GB Fibre channel > A more suitable partitioning for an OLTP database would be: 2 x 73.4 GB RAID 1 for App Server + Postgresql and pg_xlog 8 x 73.4 GB RAID 10 for pgdata RAID 5 is strongly discouraged. > > Following is the output of TOP command during offpeak time. > > > top - 18:36:56 up 77 days, 20:33, 1 user, load average: > 12.99, 9.22, 10.37 > Tasks: 142 total, 12 running, 130 sleeping, 0 stopped, 0 zombie > Cpu(s): 46.1%us, 1.9%sy, 0.0%ni, 6.1%id, 3.0%wa, 0.0%hi, > 0.1%si, 42.9%st > Mem: 16133676k total, 13657396k used, 2476280k free, > 450908k buffers > Swap: 14466492k total, 124k used, 14466368k free, > 11590056k cached > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ > COMMAND > 22458 postgres 19 0 2473m 477m 445m R 40 3.0 0:15.49 > postmaster > 22451 postgres 15 0 2442m 447m 437m S 33 2.8 0:30.44 > postmaster > 22464 postgres 17 0 2443m 397m 383m R 28 2.5 0:13.78 > postmaster > 22484 postgres 16 0 2448m 431m 412m S 20 2.7 0:02.73 > postmaster > 22465 postgres 17 0 2440m 461m 449m R 15 2.9 0:03.52 > postmaster > 22452 postgres 16 0 2450m 727m 706m R 13 4.6 0:23.46 > postmaster > 22476 postgres 16 0 2437m 413m 405m S 13 2.6 0:06.11 > postmaster > 22485 postgres 16 0 2439m 230m 222m R 7 1.5 0:05.72 > postmaster > 22481 postgres 15 0 2436m 175m 169m S 7 1.1 0:04.44 > postmaster > 22435 postgres 17 0 2438m 371m 361m R 6 2.4 1:17.92 > postmaster > 22440 postgres 17 0 2445m 497m 483m R 5 3.2 1:44.50 > postmaster > 22486 postgres 17 0 2432m 84m 81m R 4 0.5 0:00.76 > postmaster > Are you running several Postgres clusters on this hardware? Please post Top output showing cmd line arguments (press 'c') > > User Access > Total Number of Users is 500 > Maximum number of Concurrent users will be 500 during peak time > Off Peak time the maximum number of concurrent user will be > around 150 to 200. > A connection pooler like pgpool or pgbouncer would considerably reduce the burden on your system. Regards, Fernando. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
