Hi guys,
Ulrich - thanks for the suggestions - btrfs in particular is certainly worth a shot.
Quanah - very cool to hear about the 12.04 kernel and ext2 suggestions. thanks!
I've just run some new tests on a similar machine with 12.04.4 LTS and a newly installed 3.11.0-15-generic x86_64 kernel.
Exact same testing method as before, 10K records, etc:
Running on an ext4 partition:
Base-line, no extra options: 5m14s With "writemap" enabled: 9m40s With "writemap+mapasync" enabled: 4m35s
Overall, about the same as 10.04 for me.
I created a new ext2 partition to give that a shot on the 12.04 box.
Base-line, no extra options: 1m31s With "writemap" enabled: 1m33s With "writemap+mapasync" enabled: 1m41s
Ahah! I'd say that's the killer answer.
Summary for future generations who may see this thread:
1) Using ext2 for your db directory (on Ubuntu at least) is waay faster than ext4 (~2-3x as fast according to my tests). This is the secret as far as I'm concerned since you can use this while still using the most conservative DB options that don't risk your data. 2) Using "dbnosync+checkpoint" with mdb is the absolute fastest method, but at the cost of risking data loss
Cheers, Andrew
On Thu, Feb 6, 2014 at 5:08 AM, Ulrich Windl < Ulrich.Windl@rz.uni-regensburg.de> wrote:
Andrew Eross eross@locatrix.com schrieb am 05.02.2014 um 16:30 in
Nachricht CAL_tfFf2qW5BcT=Xs4uFOSUO=wL0AN=9CyfS+D-XYPLitMZ_aw@mail.gmail.com:
Hi Quanah,
Ubuntu 10.04 LTS Linux 2.6.32-43-generic-pae #97-Ubuntu SMP Wed Sep 5 16:59:17 UTC 2012
i686
GNU/Linux The latest OpenLDAP 2.4.39 All of those tests done with the mdb backend, of course, and the actual file system is ext4
Did you try btrfs? I'd guess it could be faster for massive random writes.
It's a fairly stock 10.04 system, no special config/kernel changes.
Cheers, Andrew
On Wed, Feb 5, 2014 at 1:26 PM, Quanah Gibson-Mount <quanah@zimbra.com wrote:
--On Tuesday, February 04, 2014 6:52 PM -0200 Andrew Eross < eross@locatrix.com> wrote:
Thanks, Dieter, Quanah.
I've been doing some experimenting with those mdb options.
I ran a few tests with inserting 10,000 records, wiping the DB in between, and changing just the one option at a time:
Base-line, no extra options: 4m8sWith "writemap" enabled: 8m55s
With "writemap+mapasync" enabled: 5m12s With "dbnosync+checkpoint 0kb/1min": 0m14s
I know you answered some of this before, but please update with:
What kernel? What OpenLDAP version? What Ubuntu release? What filesystem for the LDAP DB?
Thanks,
Quanah
--
Quanah Gibson-Mount Architect - Server Zimbra, Inc.
Zimbra :: the leader in open source messaging and collaboration