Problem with httpd and virtual memory

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marving
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Posts: 1
Joined: Mon Feb 25, 2013 9:13 pm
Location: Berlin

Problem with httpd and virtual memory

Unread post by marving »

Hello everybody,

first sorry for my bad english, i understand everything but its hard to write english on my own. :) I dont know where to post this problem, so i hope anybody in here can help me.

I got this strange behaviour of httpd crashing on too many connections without leaving any errors in any log-file. After installing ASL the memory usage of every httpd-process raised pretty much, so i checked out /proc/meminfo and i found out, that committed_AS is rediculously high and i am reaching the CommitLimit on high load. So i tuned the CommitLimit a little bit and now i got this:

# cat /proc/meminfo
MemTotal: 99025576 kB
MemFree: 83810664 kB
Buffers: 449224 kB
Cached: 4863384 kB
SwapCached: 0 kB
Active: 8814532 kB
Inactive: 3480920 kB
Active(anon): 6984508 kB
Inactive(anon): 1628 kB
Active(file): 1830024 kB
Inactive(file): 3479292 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 523260 kB
SwapFree: 523260 kB
Dirty: 12664 kB
Writeback: 0 kB
AnonPages: 6983024 kB
Mapped: 116056 kB
Shmem: 3108 kB
Slab: 1680788 kB
SReclaimable: 1552612 kB
SUnreclaim: 128176 kB
KernelStack: 6128 kB
PageTables: 149032 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 2971290540 kB
Committed_AS: 57030624 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 494864 kB
VmallocChunk: 34292636056 kB
DirectMap4k: 2048 kB
DirectMap2M: 2062336 kB
DirectMap1G: 98566144 kB

I would never hit the CommitLimit, but when the server is on high load the committed_AS value raises to 150G and then nobody can connect to my websites but httpd is not crashing and nothing is reported in the logs.

Without any messages in the logs i have no idea what to do to fix the problem. :?

Can anybody give me advise?
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mikeshinn
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Re: Problem with httpd and virtual memory

Unread post by mikeshinn »

How much memory is each apache process using?

Are you using form, or MPM?

How many child apache processes are you using?

What version of apache are you using?

Whats the output of these commands:

asl -v

uname -a

yum check-updates

Is this a vendor (Redhat, Centos, etc.) or a source built apache (Cpanel, custom build, etc.)?
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