Re: Proper values for threads and tool-threads

[Quanah Gibson-Mount <quanah@zimbra.com>]

--On Sunday, June 05, 2011 5:41 PM -0500 Mark <mah042@gmail.com> wrote:

> I'm setting up a new installation of OpenLDAP 2.4.25 on RHEL machines
> each with 128GB RAM and 4 Intel Xeon E7530 CPUs (6 cores each, each core
> supporting two threads). /proc/cpuinfo shows there are 48 processors. The
> backend hdb database will eventually have millions of records with
> thousands of concurrent readers and writers. Is there a good equation to
> use for determining a value for threads and tool-threads? I'd like to
> take advantage of the hardware available. I get a warning if I set
> threads higher than 32:
>
> olcThreads: value #0: warning, threads=48 larger than twice the default
> (2*16=32); YMMV.
>
> I shouldn't be slapcat'ing and slapadd'ing it very often, but like to set
> tool-threads to an appropriate value for the hardware.

How many real cores do you have?

Generally tool-threads should be set to that number.

Generally threads should be set to no more than 4 threads per real core 
IIRC (8 is generally good for 1 or 2 cores, 16 for 4 cores, etc).

--Quanah


--

Quanah Gibson-Mount
Sr. Member of Technical Staff
Zimbra, Inc
A Division of VMware, Inc.
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