Re: slapd hangs up and uses 100% CPU (v2.1.12 release)

[Jehan PROCACCIA <Jehan.Procaccia@int-evry.fr>]

I have the same pb, but cannot reproduct it as I want ...
However I noticed that when I stoped playing with bdb tunning it worked 
better ... By playing with bdb, i mean using the cachesize and 
checkpoint directives in slapd.conf, if you put silly values, as I might 
have done, this will maybe trash slapd ... ? Since I put reseaonable 
values, now it seems to work fine .

my slapd.conf

#cachesize      6000
checkpoint      100000 360
#dbnosync

and DB_Config file for my database

$ cat /var/lib/ldap/int/DB_CONFIG
#set the logfile size to 100MB.
#set_lg_max 104857600
#set the in-memory log buffer size
set_lg_bsize 204800
#temporary while we're slapadding the database
set_flags DB_TXN_NOSYNC
#set the (per db?) cachesize to 0GB + X bytes, split into N pieces of memory
set_cachesize 0 5120000 2


Although I still don't know which ones are used, slapd.conf directives 
or DB_CONFIG ones ??

when slapd takes 100% , could you make a strace -p pid  (pid=pid of 
slapd at 100%) to check what is is actually doing. For me it was looping 
on something, can't remember what, but it's somewhere in the list .

Let us know if you find an explanation.

Thanks.

Kirill Ponazdyr wrote:
> Greetings,
>
> We have a problem with slapd hanging up and using 100% CPU time on our
> machine when we try to do operations on a tree, it happens in random
> places but we could find one where it happens every time, when we try to
> delete a certain object in the tree. We can repro the problem as many
> times as we wish. Unfortunately the slapd has to be killed by kill -9 and
> this corrupts our databases, so we have to reload a directory (PITA).
>
> Thus two questions: Why is this stuff happening ? and is there a way to
> run a consistency check on BDB databases, thus not requiering the full
> reload ?
>
> Here are release infos, configs and debug output:
>
> Releases:
> -----------------------------------------
> Openldap v2.1.12 release
> Bdb libraries 4.1.24
> Solaris 9 Sparc with latest patch cluster
>
> HW:
> -----------------------------------------
> Sun Netra T1125 with 1 Gig RAM.
>
>
> DB_CONFIG
> -------------------------------
> set_lg_bsize 2097152
> set_cachesize 0 209715200 2
>
>
> slapd.conf:
> --------------------------------------------------------------
> include                 /etc/openldap/schema/core.schema
> include                 /etc/openldap/schema/cosine.schema
> include                 /etc/openldap/schema/nis.schema
> include                 /etc/openldap/schema/qmail.schema
> include                 /etc/openldap/schema/inetorgperson.schema
> include                 /etc/openldap/schema/qmailControl.schema
> pidfile                 /var/run/slapd.pid
> argsfile                /var/run/slapd.args
> disallow                bind_anon
> allow                   bind_v2
>
> database                bdb
> suffix                  "o=Codeangels, c=CH"
> directory               /export/ldap-databases/codeangels
> rootdn                  ** censored **
> rootpw                  ** censored **
> index                   cn,sn,uid pres,eq,approx,sub
> index                   objectClass eq
> ... snip ....
>
> Debug:
> ---------------- snip -------------------
> => access_allowed: write access granted by write(=wrscx)
> ====> bdb_unlocked_cache_return_entry_r( 526 ): returned (0)
> bdb_dn2entry_rw("cn=managers,ou=codeangels.com,ou=mail,ou=itaccounts,o=codeangels,c=ch")
> => bdb_dn2id_matched(
> "cn=managers,ou=codeangels.com,ou=mail,ou=itaccounts,o=codeangels,c=ch" )
> ====>
> bdb_cache_find_entry_dn2id("cn=managers,ou=codeangels.com,ou=mail,ou=itaccounts,o=codeangels,c=ch"):
> 542 (1 tries)
> bdb_cache_entry_db_lock: entry
> cn=managers,ou=codeangels.com,ou=mail,ou=itaccounts,o=codeangels,c=ch, rw
> 1, rc -30995 ====> bdb_cache_find_entry_id( 542 ): 542 (busy) 2
> locker = -2147483031
> bdb_cache_entry_db_lock: entry
> cn=managers,ou=codeangels.com,ou=mail,ou=itaccounts,o=codeangels,c=ch, rw
> 1, rc -30995 ====> bdb_cache_find_entry_id( 542 ): 542 (busy) 2
> locker = -2147483031
> bdb_cache_entry_db_lock: entry
> cn=managers,ou=codeangels.com,ou=mail,ou=itaccounts,o=codeangels,c=ch, rw
> 1, rc -30995 ====> bdb_cache_find_entry_id( 542 ): 542 (busy) 2
> locker = -2147483031
> .... repeat above 2 lines until killed ....
> ---------------- snip -------------------
>
> ---
> Kirill Ponazdyr
> Technical Director
> Codeangels Solutions
> Tel: +41 (0)43 844 90 10
> Fax: +41 (0)43 844 90 12