Re: (ITS#5664) Deadlocks when writing in parallell (two processes)

[hyc@symas.com]

stelios.xx.grigoriadis@ericsson.com wrote:
> tom.bjorkholm@aastra.com wrote:
>> Full_Name: Stelios Grigoriadis&  Tom Björkholm
>> Version: 2.3.39
>> OS: Novell SLES 10
>> URL: ftp://ftp.openldap.org/incoming/
>> Submission from: (NULL) (194.237.142.7)
>>
>>
>> We get a lot of DB_LOCK_DEADLOCK when using client programs that for a period of
>> time continuously writes to OpenLDAP.
>> Version is 2.3.39.
>>
>> The information added is of the form:
>> ebcmdCustomer=0+ebcmdDir=220xx,ou=AuthCodes,ebcmdVersion=0,ebcmdProduct=ebcmd,dc=example,dc=com
>> where xx varies.
>>
>> Snippet of the output:
>> Mar 27 13:03:21 ldapt1 slapd[7589]: =>  bdb_dn2id_add: subtree
>> (ebcmdCustomer=0+ebcmdDir=22037,ou=authcodes,ebcmdVersion=0,ebcmdProduct=ebcmd,dc=example,dc=com)
>> put failed: -30995
>> Mar 27 13:03:26 ldapt1 slapd[7589]: =>  bdb_idl_insert_key: c_put id failed:
>> DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock (-30995)
>> Mar 27 13:03:26 ldapt1 slapd[7589]: =>  bdb_dn2id_add: parent
>> (ou=authcodes,ebcmdVersion=0,ebcmdProduct=ebcmd,dc=example,dc=com) insert
>> failed: -30995
>> Mar 27 13:03:28 ldapt1 slapd[7589]: =>  bdb_idl_insert_key: c_put id failed:
>> DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock (-30995)
>> Mar 27 13:03:28 ldapt1 slapd[7589]: =>  bdb_dn2id_add: parent
>> (ou=authcodes,ebcmdVersion=0,ebcmdProduct=ebcmd,dc=example,dc=com) insert
>> failed: -30995
>> Mar 27 13:03:36 ldapt1 slapd[7589]: =>  bdb_idl_insert_key: c_put id failed:
>> DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock (-30995)
>> Mar 27 13:03:36 ldapt1 slapd[7589]: =>  bdb_dn2id_add: parent
>> (ou=authcodes,ebcmdVersion=0,ebcmdProduct=ebcmd,dc=example,dc=com) insert
>> failed: -30995
>> Mar 27 13:03:38 ldapt1 slapd[7589]: =>  bdb_idl_insert_key: c_put id failed:
>> DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock (-30995)
>>
>>
>>
>
> We've temporarily fixed the problem by introducing a static mutex before
> any add/update operation.

There's no problem to fix. Deadlocks are normal in these scenarios, and the 
code automatically retries. This ITS will be closed.

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/