On 03.04.2012 17:41, Howard Chu wrote:

...

So, am i doing something wrong or openldap is...?

Looks like your glibc malloc is deadlocked. A Centos bug, not an OpenLDAP bug.

In the trace, you could confirm this in gdb with: thread 13 frame 3 print *mutex

most likely the "owner" field of this mutex will be 1502, which corresponds to thread 17, which is waiting for a lock inside libc malloc/free.

You may be able to avoid this bug by using an alternate malloc library, such as Google tcmalloc.

Hi.

Thanx for inside info ... :-)

And sorry that i was unable to provide more info - core dump alone is 16gb! Also, small sidenote - when this "hang" happens, it only affects existing connections - i'm attacking it with two procesess, each 4 connection. New searches using ldapsearch work fine ...

And correction for typo - by "high load" i wrote (1-2 req/sec) - actually it should write 1-2k reg/sec ...

What is interesting regarding this, that this "problem" goes back to db-4.7 and openldap-2.4.23 (provided with centos) ...

I'll try alternate malloc and report back ...

H.