Re: postgres invoked oom-killer

Lacey Powers ha scritto:
> Silvio Brandani wrote:
>> We have a postgres 8.3.8 on linux
>>
>> We get following messages int /var/log/messages:
>>
>> May 6 22:31:01 pgblade02 kernel: postgres invoked oom-killer:
>> gfp_mask=0x201d2, order=0, oomkilladj=0
>> May 6 22:31:01 pgblade02 kernel:
>> May 6 22:31:01 pgblade02 kernel: Call Trace:
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff800bed05>]
>> out_of_memory+0x8e/0x2f5
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff8000f071>]
>> __alloc_pages+0x22b/0x2b4
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff80012720>]
>> __do_page_cache_readahead+0x95/0x1d9
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff800618e1>]
>> __wait_on_bit_lock+0x5b/0x66
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff881fdc61>]
>> :dm_mod:dm_any_congested+0x38/0x3f
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff800130ab>]
>> filemap_nopage+0x148/0x322
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff800087ed>]
>> __handle_mm_fault+0x1f8/0xdf4
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff80064a6a>]
>> do_page_fault+0x4b8/0x81d
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff80060f29>]
>> thread_return+0x0/0xeb
>> May 6 22:31:19 pgblade02 kernel: [<ffffffff8005bde9>]
>> error_exit+0x0/0x84
>> May 6 22:31:27 pgblade02 kernel:
>> May 6 22:31:28 pgblade02 kernel: Mem-info:
>> May 6 22:31:28 pgblade02 kernel: Node 0 DMA per-cpu:
>> May 6 22:31:28 pgblade02 kernel: cpu 0 hot: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 0 cold: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 1 hot: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 1 cold: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 2 hot: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 2 cold: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 3 hot: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: cpu 3 cold: high 0, batch 1 used:0
>> May 6 22:31:28 pgblade02 kernel: Node 0 DMA32 per-cpu:
>> May 6 22:31:28 pgblade02 kernel: cpu 0 hot: high 186, batch 31 used:27
>> May 6 22:31:29 pgblade02 kernel: cpu 0 cold: high 62, batch 15 used:54
>> May 6 22:31:29 pgblade02 kernel: cpu 1 hot: high 186, batch 31 used:23
>> May 6 22:31:29 pgblade02 kernel: cpu 1 cold: high 62, batch 15 used:49
>> May 6 22:31:29 pgblade02 kernel: cpu 2 hot: high 186, batch 31 used:12
>> May 6 22:31:29 pgblade02 kernel: cpu 2 cold: high 62, batch 15 used:14
>> May 6 22:31:29 pgblade02 kernel: cpu 3 hot: high 186, batch 31 used:50
>> May 6 22:31:29 pgblade02 kernel: cpu 3 cold: high 62, batch 15 used:60
>> May 6 22:31:29 pgblade02 kernel: Node 0 Normal per-cpu:
>> May 6 22:31:29 pgblade02 kernel: cpu 0 hot: high 186, batch 31 used:5
>> May 6 22:31:29 pgblade02 kernel: cpu 0 cold: high 62, batch 15 used:48
>> May 6 22:31:29 pgblade02 kernel: cpu 1 hot: high 186, batch 31 used:11
>> May 6 22:31:29 pgblade02 kernel: cpu 1 cold: high 62, batch 15 used:39
>> May 6 22:31:29 pgblade02 kernel: cpu 2 hot: high 186, batch 31 used:14
>> May 6 22:31:29 pgblade02 kernel: cpu 2 cold: high 62, batch 15 used:57
>> May 6 22:31:29 pgblade02 kernel: cpu 3 hot: high 186, batch 31 used:94
>> May 6 22:31:29 pgblade02 kernel: cpu 3 cold: high 62, batch 15 used:36
>> May 6 22:31:29 pgblade02 kernel: Node 0 HighMem per-cpu: empty
>> May 6 22:31:29 pgblade02 kernel: Free pages: 41788kB (0kB
>> HighMem)
>> May 6 22:31:29 pgblade02 kernel: Active:974250 inactive:920579
>> dirty:0 writeback:0 unstable:0 free:10447 slab:11470 mapped-file:985
>> mapped-anon:1848625 pagetables:111027
>> May 6 22:31:29 pgblade02 kernel: Node 0 DMA free:11172kB min:12kB
>> low:12kB high:16kB active:0kB inactive:0kB present:10816kB
>> pages_scanned:0 all_unreclaimable? yes
>> May 6 22:31:29 pgblade02 kernel: lowmem_reserve[]: 0 3254 8052 8052
>> May 6 22:31:29 pgblade02 kernel: Node 0 DMA32 free:23804kB
>> min:4636kB low:5792kB high:6952kB active:1555260kB inactive:1566144kB
>> present:3332668kB pages_scanned:35703257 all_unreclaimable? yes
>> May 6 22:31:29 pgblade02 kernel: lowmem_reserve[]: 0 0 4797 4797
>> May 6 22:31:29 pgblade02 kernel: Node 0 Normal free:6812kB
>> min:6836kB low:8544kB high:10252kB active:2342332kB
>> inactive:2115836kB present:4912640kB pages_scanned:10165709
>> all_unreclaimable? yes
>> May 6 22:31:29 pgblade02 kernel: lowmem_reserve[]: 0 0 0 0
>> May 6 22:31:29 pgblade02 kernel: Node 0 HighMem free:0kB min:128kB
>> low:128kB high:128kB active:0kB inactive:0kB present:0kB
>> pages_scanned:0 all_unreclaimable? no
>> May 6 22:31:29 pgblade02 kernel: lowmem_reserve[]: 0 0 0 0
>> May 6 22:31:29 pgblade02 kernel: Node 0 DMA: 3*4kB 5*8kB 3*16kB
>> 6*32kB 4*64kB 3*128kB 0*256kB 0*512kB 2*1024kB 0*2048kB 2*4096kB =
>> 11172kB
>> May 6 22:31:29 pgblade02 kernel: Node 0 DMA32: 27*4kB 0*8kB 1*16kB
>> 0*32kB 2*64kB 4*128kB 0*256kB 1*512kB 0*1024kB 1*2048kB 5*4096kB =
>> 23804kB
>> May 6 22:31:29 pgblade02 ker
>> if it asks for more memory than is actually available.
>> nel: Node 0 Normal: 21*4kB 9*8kB 26*16kB 3*32kB 6*64kB 5*128kB
>> 0*256kB 0*512kB 1*1024kB 0*2048kB 1*4096kB = 6812kB
>> May 6 22:31:29 pgblade02 kernel: Node 0 HighMem: empty
>> May 6 22:31:29 pgblade02 kernel: Swap cache: add 71286821, delete
>> 71287152, find 207780333/216904318, race 1387+10506
>> May 6 22:31:29 pgblade02 kernel: Free swap = 0kB
>> May 6 22:31:30 pgblade02 kernel: Total swap = 8388600kB
>> May 6 22:31:30 pgblade02 kernel: Free swap: 0kB
>> May 6 22:31:30 pgblade02 kernel: 2293759 pages of RAM
>> May 6 22:31:30 pgblade02 kernel: 249523 reserved pages
>> May 6 22:31:30 pgblade02 kernel: 56111 pages shared
>> May 6 22:31:30 pgblade02 kernel: 260 pages swap cached
>> May 6 22:31:30 pgblade02 kernel: Out of memory: Killed process 29076
>> (postgres).
>>
>>
>> We get folloowing errors in the postgres log:
>>
>> A couple of time:
>> 2010-05-06 22:26:28 CEST [23001]: [2-1] WARNING: worker took too
>> long to start; cancelled
>> Then:
>> 2010-05-06 22:31:21 CEST [29059]: [27-1] LOG: system logger process
>> (PID 29076) was terminated by signal 9: Killed
>> Finally:
>> 2010-05-06 22:50:20 CEST [29059]: [28-1] LOG: background writer
>> process (PID 22999) was terminated by signal 9: Killed
>> 2010-05-06 22:50:20 CEST [29059]: [29-1] LOG: terminating any other
>> active server processes
>>
>> Any help higly apprecaited,
>>
>> ---
>>
>
> Hello Silvio,
>
> Is this machine dedicated to PostgreSQL?
>
> If so, I'd recommend adding these two parameters to your sysctl.conf
>
> vm.overcommit_memory = 2
> vm.overcommit_ratio = 0
>
> So that OOMKiller is turned off.
>
> PostgreSQL should gracefully degrade if a malloc() fails because it
> asks for too much memory.
>
> Hope that helps. =)
>
> Regards,
> Lacey
>
>

Thanks a lot,
yes the server is dedicated to PostgreSQL.

Could be a bug of PostgreSQL the fact that the system went Out of
Memory?? Wath can be the cause of it?

Regards,
Silvio

--
Silvio Brandani
Infrastructure Administrator
SDB Information Technology
Phone: +39.055.3811222
Fax: +39.055.5201119

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