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RE: Speeding up BDB question




> -----Original Message-----
> From: Quanah Gibson-Mount [mailto:quanah@zimbra.com]
> Sent: Tuesday, April 05, 2011 12:50 PM
> To: Cannady, Mike; Christian Kratzer
> Cc: openldap-technical@openldap.org
> Subject: RE: Speeding up BDB question
> 
> 
> 
> --On April 5, 2011 7:58:19 AM -0400 "Cannady, Mike"
> <mike.cannady@htcinc.net> wrote:
> 
> 
> > I agree.  I saw no hint of using sysv shared memory anywhere in the
> > openldap FAQ.  I assume that "DB_SYSTEM_MEM" would have to be in the
> > DB_CONFIG file and "dbconfig set_flags DB_SYSTEM_MEM" in slapd.conf
to
> > cover a new database.  Is this correct?
> 
> I'm talking about shared memory keys, which is documented in the
> slapd-bdb(5) and slapd-hdb(5) manual pages.

I was looking at the BDB documentation and missed it in slapd-bdb.  I
reconfigured both masters to use shm_key, removed dncachesize and ran
ldapadd.  It took only 50 minutes to load 51,265 DNs.  That is a better
than the 6-8 hours before.  There still seemed to be a lot of small cpu
usage and a lot of I/O waiting.  

> 
> > I used the ram filesystem to see if there was a lot of filesystem
> > flushing via some kind of sync.  The I/Os I saw just didn't seem
right
> > for the amount of changes happening every minute.
> >
> > As to the database size and such:  The ldapadd was adding 51,265 DNs
> > back into the ldap store.  The preceding delete was close to that
number
> > also.  The database before any of the operations had 71,886 DNs
> 
> Then it is clear your cachesize and idlcachesize settings are all too
> small.  I would also note you should never, *EVER*, set the
dncachesize
> unless you are on a terribly memory restricted machine.  You should
always
> leave it at the default of infinite.
> 
> You still fail to note the size of the BDB database (du -c -h *.bdb)
so
> again it is impossible to say if your DB_CONFIG settings are correct.
>

Sorry about missing the size of the database... Here it is ( 71,914 DNs
):

[root@LDAPdev1 openldap-data]# du -c -h *.bdb
35M     cn.bdb
16M     dn2id.bdb
3.5M    entryCSN.bdb
2.2M    entryUUID.bdb
18M     givenName.bdb
96M     id2entry.bdb
3.2M    objectClass.bdb
9.0K    ou.bdb
21M     sn.bdb
20M     uid.bdb
2.0M    uniqueIdentifier.bdb
214M    total


 
> --Quanah
> 
> 
> --
> Quanah Gibson-Mount
> Principal Software Engineer
> Zimbra, Inc
> --------------------
> Zimbra ::  the leader in open source messaging and collaboration

I'll bump up the cachesize to 100,000 and idlcachesize to 300,000 and
rerun my tests.  


---Thanks for the help!
---Mike Cannady


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