[Date Prev][Date Next] [Chronological] [Thread] [Top]

RE: Memory and CPU usage

--On Sunday, February 16, 2003 4:20 PM -0500 Adam Williams <awilliam@whitemice.org> wrote:

I see a lot of memory problems with back-bdb when a particular
configuration is set to allow too many threads.
I've never specified a threads statement in slapd.conf. The default is
32  threads. Is that too high on some machines?

Yes, my master runs at 9. Stress testing shows a peak at 8 - 10, so I picked 9. (This is a 2xPro200 with 384Mb and UW SCSI, LDAP database striped across two drives. Albeit it isn't a current machine, but testing newer machines shows that threads seems to top out about ~12 on x86 boxes).

When you
spawn so many threads that all of the free RAM in your address space is
consumed, slapd aborts because it cannot allocate any more dynamic
memory for its normal operation.
This is not the case with my machine. There must be something else wrong.

I've never had slapd crap out, but it does get stuttery if you push up the thread count and utilization too high. But I allocate a great deal of swap, RAMx4.

We use a limit of 20 threads on our Solaris UltraSparc machines, and that seems to work well.


Quanah Gibson-Mount
Senior Systems Administrator
ITSS/TSS/Computing Systems
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html