ktm@xxxxxxxx wrote:
On Tue, Nov 01, 2011 at 11:57:57AM -0400, Mark London wrote:
Hi - On RHEL 6, with the latest updates, I have SASLAUTHD configured
to use PAM authentication. I'm also running SSSD. U sing this
configuration, the SASLAUTHD processes would gradually increase
memory usage. After running for several days, each process was
using up about 680M. Are there any known memory leaks when using
PAM? I've found posts on the web from people complaining about PAM
memory leaks, but am not sure they still exists. In any event, I'm
also experiencing that about once a week, SASLAUTHD starts recording
time out errors when trying to contact SSSD, i.e.
"pam_sss(imap:auth): Request to sssd failed. Timer expired." I
decided to enable SASLAUTHD caching with the -c flag, and was
surprised to discover that the SASLAUTHD processes no longer use up
significant memory (i.e. they are now using < 10M)! Can anyone
explain this behavior? Thanks. - Mark
Each trip through the PAM stack loses some memory. When you turn on
caching, you make a single trip for each authentication via SASL
and then it uses the cached copy from then on. This bounds your
memory use to N x num-users. Without caching, the growth as you
found is unbounded.
Thanks for the info! But without caching, does the Mailman related
memory use, eventually get freed up?
Also, are there any bad side effects from turning on caching? If not,
why isn't it the default?
- Mark
