Re: 32 bit to 64 bit migration performance problems

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

--On Thursday, June 21, 2007 8:55 AM -0700 erin crego <ecav22@yahoo.com> 
wrote:

> I am moving our ldap instances to new servers; the old servers are 32
> bit, the new ones are 64 bit.  I have compiled the same versions of bdb
> (4.2.52) and openldap (2.2.26) with the same flags on the new servers.
> After running DirectoryMark tests, I have found the operations per second
> has gone down 33% - from 299 on the old servers to 192 on the new ones.
> I have tried adding what I think are the 64 bit flags to the compilation
> of bdb and openldap.  LDFLAGS='-m64' and CFLAGS='-m64'
> This has resulted in the operations/second going down further to 52.
>
> Are there different compilation flags I should use for 64 bit systems?
> Or, is the performance change of -33% to be expected when moving from 32
> bit to 64 bit?


You need to upgrade to a decent modern version of OpenLDAP to begin with 
(2.3.36 is the current release).  Second, you may have to make adjustments 
to the tuning.  However, I've not seen performance issues in my 64-bit 
Linux servers.  I'll also note that DirectoryMark is not a particularly 
valid method of determining performance.  Use something distributed like 
slamd.

You may wish to read over:

<http://www.symas.com/benchmark-auth.shtml>

which were all done on 64-bit servers.

--Quanah

--
Quanah Gibson-Mount
Principal Software Engineer
Zimbra, Inc
--------------------
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