DS6 export/import performance
Hi,
is it just me, or is LDIF export quite slow in DS6? For example:
725,000 Entries, DS6:
offline dsadm export: 44 minutes
online dsconf export: 44 minutes
online dsconf export -Q: 53 minutes
offline db2ldif -r: 47 minutes
As opposed to that:
725,000 Entries, DS5.2P4 (same machine, same cache sizes):
online db2ldif: 13 minutes
offline db2ldif -r: 10 minutes
Also import seems to be a bit slower for DS6.
I really liked the fast LDIF export, hope this gets fixed (if it's not a problem with my configuration).
Cheers,
Holger
[618 byte] By [
Ewirona] at [2007-11-26 20:46:33]
# 2
Hi Ludovic,
thanks for your fast response. Here are some more details:
SunOS <servername> 5.10 Generic_118822-19 sun4u sparc SUNW,Sun-Fire-V240, 8GB RAM
I have 2 identical whole root zones, one with DS5.2P4 and one with DS6 + DPS6. The LDIF export is around 1,5GB large.
I checked iostat, for DS6 export the disk is roughly as busy as for DS5.2P4, although the export for DS6 is much slower. So maybe the disk is the limiting factor. The question is why the disk load is almost the same, although DS6 throughput is around 4x less?
Is there more information you need? Or any more ideas for tests I can do locally to find out if there is a problem with the installation/configuration?
Cheers,
Holger
# 3
>>I checked iostat, for DS6 export the disk is roughly as busy as for DS5.2P4, although the export for DS6 is much slower. So maybe the disk is the limiting factor. The question is why the disk load is almost the same, although DS6 throughput is around 4x less?
Sorry, this information was wrong, I checked again. Disk usage was much higher with DS6. Busy percentages during export were roughly:
DS5.2P4: 40-50%
DS6: 80-90%
Then I realized some configuration difference, db cache files location was not in /tmp for DS6. After I changed that, performance for DS6 was much better:
DS6: 60-70% disk busy
15 minutes export time
Still not as fast as DS5.2P4, but acceptable for me.
# 4
Thanks for the update.
It had to be a configuration difference. A 3 times slower difference is definitely not something that we would accept in our product.
Still there is a small difference between 5.2 and 6.0 that I am not sure to explain. We have engineers looking at this right now and I will post what we observed precisely.
How many times did you try to export to check that these numbers are reproducible and thus not affected by other things going on in the machine ?
Are all the DB files for both servers on the same disk (except with the /tmp db-home-directory) ?
Regards.
Ludovic.
# 5
All other files used by the directory server are on the same disk (2 mirrored local disks).
I ran the export 3 times, the result is reproducible. The machine is almost idle otherwise:
Online export without replication information:
dsconf export -Q ...
DS6: 15 minutes for all 3 runs
db2ldif ...
DS5.2P4: 8-9 minutes for all 3 runs
Interesting is that during export iostat shows about 600 reads/s for DS6, and only about 100 reads/s for DS5.2P4.
Regards,
Holger
