Re: BDB-openldap performance

[Quanah Gibson-Mount <quanah@stanford.edu>]

--On Tuesday, May 31, 2005 1:25 PM +0000 Manel Euro <euro_32@hotmail.com> 
wrote:

> Hello,
>
> I am having performance problems on my openldap-2.2.26 and Berkeley
> 4.3.28.NC.
> I have installed this combo on a PIII 1.0Ghz with 512 Mb and an IDE drive.
> Every client has nscd configured and running.
> Whenever a client does:
> cd ~username (and then tab) I get the following error:
>
> Ex: my username is tsoli;when I do cd ~tso(and TAB) it circles the globe
> two times :) and gives me tsoli.
>
> Here is the error:
> /usr/local/openldap-2.2.26/libexec/slapd -d 4
>
> SRCH "ou=People,dc=ex,dc=com" 2 3    0 30 0
>     filter: (&(objectClass=posixAccount)(uid=public))
>     attrs: cn uid uidnumber gidnumber gecos description homeDirectory
> loginshell
> bdb_idl_fetch_key: [01872a84]
> bdb_idl_fetch_key: @ou=people,dc=ex,dc=com
> bdb_idl_fetch_key: [b49d1940]
> bdb_idl_fetch_key: [5941c014]
> bdb_idl_fetch_key: [6a7fc8b1]
> send_ldap_result: err=0 matched="" text=""
>
>
>
> Here is the bdb section in slapd.conf
>
> # Indices to maintain
> index   objectClass     eq
> index   cn,sn           eq,pres,sub
> # Indexes para optimizar o acesso  para as funcoes getpwuid(), getpwnam()
> # e getgrgid()
> index   uid             eq,sub
> index   uidNumber,loginShell    eq
> index   gidNumber       eq
> index   uniqueMember    pres
> index   memberUid       eq,pres,sub

cachesize applies to the number of entries in your database.  Do you really 
have 1,500,000 entries in your DB?

> cachesize       1500000

The dbcachesize parameter does not apply to back-bdb if that is the 
database you are using.  It only applies to back-ldbm.

> dbcachesize     80000000
>
> DB_CONFIG:
> # logfile 100MB, a BDB .
> set_lg_max 104857600
> # set the in-memory log buffer size
> set_lg_bsize 262144
> # temporary while we're slapadding the database
> set_flags DB_TXN_NOSYNC
> # set the cachesize to 0GB + X bytes, split into N pieces of memory.
> set_cachesize 0 150000 1
>
> I got 150Kb when performing the calculations recommended in the OpenLdap
> FAQ.

I would guess that 150KB is way too small.  Try at least a few megabytes.

I will note that it is suggested to use OpenLDAP with BDB 4.2.52+patches, 
and not with BDB 4.3.x.  The problem you are seeing itself seems to be a 
problem with nscd (why is it searching for uid=public?).

--Quanah


--
Quanah Gibson-Mount
Principal Software Developer
ITSS/Shared Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html