Re: shared memory weirdness
Ian Spare wrote:
>We're running a very old version of HPUX and Informix, the system will
>shortly be retired so we're limping along for a short time.
>
>We're running out of shared memory though and it's killing the database,
>to an extent it's something we're going to have live with but something
>puzzles me.
>
> From onstat -g seg :
>
>INFORMIX-OnLine Version 7.23.UC6 -- On-Line -- Up 00:56:47 -- 1077264
>Kbytes
>
>Segment Summary:
>(resident segments are not locked)
>id key addr size ovhd class blkused blkfree
>1030 1383417858 a0000000 440410112 7328 V 10578 43183
>1031 1383417859 c0836000 606208 616 M 67 7
>7172 1383417857 c0bba000 662708224 10992 R 80891 6
>Total: - - 1103724544 - - 91536 43196
>
>Which looks perfectly normal. But, from ipcs -ma :
>
>
>m 7172 0x52754801 --rw-rw---- root informix root informix
> 33 662708224 17645 18885 11:30:00 11:30:00 10:35:29
>
>m 1797 0x00000000 D-rw-rw---- root informix root informix
> 33 536870912 17645 17645 10:35:29 no-entry 10:35:29
>
>m 1030 0x52754802 --rw-rw---- root informix root informix
> 33 440410112 17645 18885 11:30:00 11:30:00 10:35:38
>
>m 1031 0x52754803 --rw-rw-rw- root informix root informix
> 34 606208 17671 18983 11:30:47 11:30:00 10:35:49
>
>So we have a segment, number 1797, that's pretty big, created and last
>accessed by the same process as the other segments, it's been removed
>but won't get returned to the free list until the oninit exits.
>
>So, my question is this, what's happening here? And, can I stop it doing
> it?
>
>Ian
>
>
>
What's happening? A resource allocation "bug". Can you stop it? Yes.
Several ways.
Turning Informix off will work. A better solution: Ugrade to a newer
version. Probably
not a solution compatible with retiring your current system, though.
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