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Thread: problem with memory

problem with memory

From
Pavel Stehule
Date:
Hello

one czech PostgreSQL user reports problem with memory - probable memleak?

Is possible to diagnose some from log?

Postgres  ver. 8.3.7 .
Server 8G RAM,  32b Debian Etch.

Configuration:
shared_buffers = 324000        # min 16 or max_connections*2, 8KB each
temp_buffers = 16000            # min 100, 8KB each
work_mem = 8126            # min 64, size in KB
maintenance_work_mem = 16384        # min 1024, size in KB
max_stack_depth = 7680            # min 100, size in KB
max_fsm_pages = 200000            # min max_fsm_relations*16, 6 bytes
max_fsm_relations = 12000        # min 100, ~70 bytes each
effective_cache_size = 300000        # typically 8KB each

http://jyxo.cz/misc/sql.error.txt

Thank you
Pavel Stehule

Re: problem with memory

From
Tom Lane
Date:
Pavel Stehule <pavel.stehule@gmail.com> writes:
> one czech PostgreSQL user reports problem with memory - probable memleak?
> Is possible to diagnose some from log?

If he's getting an actual "out of memory" error, let's see the memory
context map that gets dumped to the server log (or more specifically,
to stderr).

> Server 8G RAM,  32b Debian Etch.
> shared_buffers = 324000        # min 16 or max_connections*2, 8KB each

Although you may have told us enough right here.  2.5GB of shared
buffers in a 4GB address space (with probably only 3GB available to the
application) isn't a very sane choice.  Back that off or run 64-bit.
        regards, tom lane

Re: problem with memory

From
Greg Stark
Date:
The link was to the memory context dump. The only suspicious context I  
spotted was 300mb in MessageContext. What is lc_messages and lc_ctype  
set to on this machine? Were the latest round of infinite recursion in  
the character conversion routines in 8.3.7?

-- 
Greg


On 26 May 2009, at 17:00, Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Pavel Stehule <pavel.stehule@gmail.com> writes:
>> one czech PostgreSQL user reports problem with memory - probable  
>> memleak?
>> Is possible to diagnose some from log?
>
> If he's getting an actual "out of memory" error, let's see the memory
> context map that gets dumped to the server log (or more specifically,
> to stderr).
>
>> Server 8G RAM,  32b Debian Etch.
>> shared_buffers = 324000        # min 16 or max_connections*2, 8KB  
>> each
>
> Although you may have told us enough right here.  2.5GB of shared
> buffers in a 4GB address space (with probably only 3GB available to  
> the
> application) isn't a very sane choice.  Back that off or run 64-bit.
>
>            regards, tom lane
>
> -- 
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> To make changes to your subscription:
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Re: problem with memory

From
Tom Lane
Date:
Greg Stark <greg.stark@enterprisedb.com> writes:
> Were the latest round of infinite recursion in  
> the character conversion routines in 8.3.7?

Yes, and in any case the typical symptom of that problem was a SIGSEGV
(due to stack overrun) not an out-of-memory complaint.
        regards, tom lane