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[LDM #DBK-582040]: 6.10.1 how to diagnose pqact memory leak?
- Subject: [LDM #DBK-582040]: 6.10.1 how to diagnose pqact memory leak?
- Date: Tue, 13 Nov 2012 10:17:56 -0700
Daryl,
> I stumbled back onto this today while diagnosing a filesystem issue. For
> example:
>
> # lsof /mesonet | grep 8681 | wc -l
> 288
>
> where 8681 is a pqact process. An example output is:
>
> pqact 8681 ldm 295w REG 9,127 849138 14697353
> /mesonet/data/text/sao/12111100.sao
> pqact 8681 ldm 296w REG 9,127 843784 14702371
> /mesonet/data/text/sao/12111315.sao
> pqact 8681 ldm 297w REG 9,127 108 14705360
> /mesonet/data/text/sao/12111317.sao
>
> This seems problematic.
Seems OK to me.
> I thought pqact was limited to 32 file descriptors
The maximum number of open file descriptors is guaranteed by the POSIX standard
to be at least 32.
The actual number can be found via the command "ulimit -a" or "getconf
OPEN_MAX". On my system, the value is 1024.
> and would start recycling them once it reached this limit.
That's correct.
> Is there a need
> for these old descriptors to lay around or are they reused when possible ?
The "need" is that the LDM user didn't specify a "-close" option -- so they
think a similar data-product that needs to be written to the same file or piped
to the same decoder is likely to arrive very soon.
Nevertheless, if the pqact(1) process needs another file-descriptor and they're
all in-use, then it will recycle the least-recently-used file-descriptor by
closing it and reopening it to the new file or decoder.
> thanks for the education,
You're most welcome.
> daryl
Regards,
Steve Emmerson
Ticket Details
===================
Ticket ID: DBK-582040
Department: Support LDM
Priority: Normal
Status: Closed