Thread: BUG #1806: Postmaster takes uses 99% of CPU
The following bug has been logged online: Bug reference: 1806 Logged by: Email address: m.krueger@chs.de PostgreSQL version: 7.4.8-0.6 Operating system: Suse Linux Enterprise Server 9 Description: Postmaster takes uses 99% of CPU Details: The Prozess Postmaster takes 99% of Cpu. PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 20726 postgres 17 0 19996 5356 4216 R 98.3 0.3 26:36.56 postmaster 19956 postgres 19 0 19996 6148 4936 R 64.4 0.3 28:38.38 postmaster 20005 postgres 24 0 19996 6244 5068 R 23.6 0.3 36:25.35 postmaster 19955 postgres 22 0 20060 6364 5156 R 10.3 0.3 34:25.64 postmaster 20014 postgres 17 0 19992 5264 4136 R 5.6 0.3 15:17.95 postmaster 10454 tomcat 25 0 608m 426m 12m S 0.3 21.1 12:47.47 java I have read all the Faq. But there is no reason to it. Could you help?
m.krueger@chs.de wrote: > The Prozess Postmaster takes 99% of Cpu. > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 20726 postgres 17 0 19996 5356 4216 R 98.3 0.3 26:36.56 postmaster > 19956 postgres 19 0 19996 6148 4936 R 64.4 0.3 28:38.38 postmaster ... > I have read all the Faq. But there is no reason to it. > Could you help? Is it doing anything? Do your logs show any activity? If you do "strace -p <pid>" as root, you'll see what system calls the backend is making. -- Richard Huxton Archonet Ltd
Mike Kr=FCger wrote: > Sorry, I lost the Email Adress of the List. No problem, just remember to hit "reply all" rather than "reply". > There are no problems with other Processes. > The System is only slow, when the postmaster Prozess gets the 100 % CPU t= ime. > Can I configure it, that this Prozess dont get more than 60 % ? Not really (on Linux anyway). However, if other processes have useful=20 work to do and need CPU time, they will get their fair share. So - if PG=20 is running at 99% CPU (for long periods) that implies all other=20 processes are either waiting for PG to respond anyway, or are waiting=20 for disk/network etc. The system shouldn't feel "slow" or "unresponsive" just because one=20 process is busy. If it does, that might imply swap is being used, or=20 network or disk activity is at a maximum. General system admin is too large a subject to deal with here, but the=20 tools to check documentation for are: top/free/vmstat/iostat/netstat Oh - and make sure your configuration settings are reasonable. Read=20 these two performance-tuning guides: http://www.varlena.com/varlena/GeneralBits/Tidbits/index.php http://www.powerpostgresql.com/PerfList HTH -- Richard Huxton Archonet Ltd