Re: Large shared_buffers freezing computers - Mailing list pgsql-bugs

From Michael G. Martin
Subject Re: Large shared_buffers freezing computers
Date
Msg-id 3C80ED0C.2000105@vpmonline.com
Whole thread Raw
In response to Indexes not always used after inserts/updates/vacuum analyze  ("Michael G. Martin" <michael@vpmonline.com>)
List pgsql-bugs
I read an earlier post by Tom where he recommends 1/4 of physical ram.
 I will go to 1/5 to be safe and I assume it will be ok.  I'm guessing
my 50% was probably overkill.

--Michael

Michael G. Martin wrote:

> I've had this happen on 2 seperate servers now.
>
> After reading the docs, I bumped up shared_buffers.  On one machine
> with 2G pyhsical ram, I set the param to use 1G of memory ( 131072
> value), on another machine with 800M of RAM, I set the value to about
> 500M ( 64000 ).  ipcs shows the correct amounts allocated.
>
> Both servers run fine for a bit, then at some point, the entire box
> freezes.  Pings work, but nothing else does, so a hard reboot is
> necessary.
>
> Any ideas.  Any limits on what you can set these to.  I thought these
> values would leave plenty for the other stuff to run on the server.
>
> Here is a top output before freezing:
>
> 9:14pm  up 38 days, 12:47,  2 users,  load average: 4.78, 5.12, 4.91
> 101 processes: 99 sleeping, 2 running, 0 zombie, 0 stopped
> CPU0 states: 24.1% user,  7.2% system,  0.0% nice, 68.1% idle
> CPU1 states: 28.0% user,  6.4% system,  0.0% nice, 64.4% idle
> Mem:   898892K av,  897300K used,    1592K free,       0K shrd,
> 0K buff
> Swap:  819272K av,   65792K used,  753480K free
> 805924K cached
>
>  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
> 3370 postgres   9   0  382M 382M  381M S     0.1 43.5  10:53 postmaster
> 32762 postgres  10   0  104M 104M  103M S    15.2 11.9  65:25 postmaster
> 1226 postgres   9   0 54372  53M 52852 S     0.0  6.0   0:08 postmaster
> 1334 postgres   9   0 47756  46M 46240 S     0.0  5.3   0:03 postmaster
> 1181 postgres   9   0 46184  45M 44592 S     0.0  5.1   0:12 postmaster
> 1227 postgres   9   0 39796  38M 38328 S     0.0  4.4   0:06 postmaster
> 1228 postgres   9   0 25072  24M 23580 S     0.0  2.7   0:05 postmaster
> 9082 postgres  10   0 16608  16M 15180 D     5.0  1.8   0:00 postmaster
> 9084 postgres  10   0 14700  14M 13316 S     4.6  1.6   0:00 postmaster
> 3244 postgres   9   0 13376  13M 12052 S     0.0  1.4   0:00 postmaster
> 32668 postgres   9   0 11488  11M 10224 S     0.0  1.2   0:02 postmaster
> 32669 postgres   9   0 11136  10M  9888 S     0.0  1.2   0:55 postmaster
> 9085 postgres  15   0 10820  10M  9520 S     2.5  1.1   0:00 postmaster
> 9087 postgres  18   0 10796  10M  9496 R     2.9  1.1   0:00 postmaster
> 9086 postgres  16   0 10696  10M  9400 S     2.3  1.1   0:00 postmaster
>
> Thanks,
> Michael
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster

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