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Re: ITS#5860 slapd in openldap-2.4.16 still doesn't respect memory bounds

--On Friday, April 17, 2009 10:25 PM +0300 sscdvp@gmail.com wrote:
Why do you have so many threads configured?  How many cpu's do you have??

I have tried openldap-2.4.16 (latest) BDB 4.7.25 with all patches from
Oracle on Dell AMD64 RAM 4Gb, 8 CPUs, OS Solaris 10.
I have an application which generates heavy load in slapd (many
ldap_search'es and very very many ldap_add, ldap_modify, ldap_delete).
BDB databases are situated on separate disk and BDB logs are on the other
disk. But slapd performance (I mean time to answer) still cuts
down during large disk IO periods 'cause these disks are used by other
applications at the same time. And so I have increased number of threads
from the defaults threads=32 up to 64, just to save some time for my
application which requires not more then 30 ms for one search to
Just to be sure I have tried the default settings for threads and it's
behaviour didn't changed - slapd heap memory just continuously grows (I
have seen through pmap)...
Also I have tried libtcmalloc which is usually recommended and solaris
built in' libmtmalloc, but it didn't helped.

Please copy replies to the bug tracker if you expect help.

I will note that every thread consumes a large chunk of memory. I will also note that the default is 16 threads, not 32. I will also note, that as far as read operations are concerned, usually *fewer* threads is faster, not more. You appear to have quite an excessive amount of threads configured.

Others will have to continue the conversation on what you're seeing growth wise. ;)



Quanah Gibson-Mount
Principal Software Engineer
Zimbra, Inc
Zimbra ::  the leader in open source messaging and collaboration