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Re: ldapsearch hangs

wow, Quanah,

thats the best answer i ever got...

I'm gong to move to 2.4.18 and try to tune up the machine... regarding more RAM ... i can get it but not tha fast.

what can i expect with a total of 10 GB ?...

I plan to set set_cachesize 7 0 1

what is the relation between cachesize (in slapd.conf) and set_cachesize (in DB_CONFIG)?

set_cachesize =>how much memory i wiill cache
cachesize => number of entries i will keep within the cache

how much one entry take ?

Lets say if i use 7 GB of cache, what cachesize should i put?


On Thu, Sep 10, 2009 at 9:37 PM, Quanah Gibson-Mount <quanah@zimbra.com> wrote:
--On Thursday, September 10, 2009 8:56 PM +0200 Tihomir Culjaga <tculjaga@gmail.com> wrote:

So, the situation is that i have 2 ldif files i'm recreating the database

/usr/local/libexec/slapadd -l /home/tculjaga/file2.ldif -f
/usr/local/libexec/slapadd -l /home/tculjaga/file2.ldif -f

I would suggest you just make these a single file, so all the work can be done at one time.

I tried to re-index with /usr/local/libexec/slapindex -f
/usr/local/etc/openldap/slapd.conf -v
restart slapd process, restart the machine ... it is always the same

Nothing here indicates a problem with your indices.  Running slapindex repeatedly is a waste of your time.

[root@l01lnp2 traces]# /usr/local/libexec/slapd -V
@(#) $OpenLDAP: slapd 2.4.16 (Sep  9 2009 14:39:44) $

I would strongly urge you to upgrade to 2.4.18 (for reasons I will note further down)

[root@l01lnp2 traces]# /usr/local/BerkeleyDB.4.7/bin/db_stat -V
Berkeley DB 4.7.25: (May 15, 2008) - unpached!

You need to rebuild BDB 4.7.25 with the 4 patches from Oracle.  There are known issues when running BDB 4.7 without them.

[root@l01lnp2 traces]# du -c -h /var/lib/ldap/*.bdb
200K    /var/lib/ldap/bestMatchPrefix.bdb
3.8G    /var/lib/ldap/dn2id.bdb
6.2G    /var/lib/ldap/id2entry.bdb
1.8M    /var/lib/ldap/objectClass.bdb
1.2M    /var/lib/ldap/originatorPrefixID.bdb
48M    /var/lib/ldap/uniqueID.bdb
10G    total

Since your database is a total of 10 GB in size, for slapadd to work at optimum efficiency, you need at least 10GB of cache for your DB_CONFIG file.  Unfortunately, you only have 10GB of RAM.  Essentially, your system is under powered for your database size.

[tculjaga@l01lnp2 ~]$ cat ot.ldif | grep -c "dn: "
[tculjaga@l01lnp2 ~]$ cat l01sipdir1.ldif | grep -c "dn: "
[tculjaga@l01lnp2 ~]$

So you have 10,096,452 entries total.

[root@l01lnp2 traces]# cat /var/lib/ldap/DB_CONFIG | grep -v "#"

set_cachesize 0 3221225472 1
set_lg_regionmax 262144
set_lg_bsize 2097152

You only have a 3GB DB cachesize configured here.  Expect things to perform sub optimally.  It would have been easier to set this by going

set_cachesize 3 0 1

Which would have the same effect, since the first number is the number of gigabytes to allocate.

Please find attached slapd.conf

Ok, so the relevant bits from here are:

cachesize 2500000
idlcachesize 7500000
cachefree 1000

Which means you have a cachesize of 2.5 million, an idlcachesize of 7.5 million, and (with OL 2.4.16) a dncachesize of 5 million.

I would highly advise you upgrade to OpenLDAP 2.4.18, and change the slapd.conf settings to:

dncachesize 0 (which means unlimited).

And setting no cache or idlcachesize, and fixing your DB_CONFIG.  But you also need to buy a substantial amount of RAM for a DB of this size. :P  I would advise you upgrade to at least 32GB total.  Then you can more optimally tune the system.



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