slapd hangs - subtree insert failed: -30995

[Meike Stone <meike.stone@googlemail.com>]

Hello,

after inserting (ADD) one object, I get following messages in the
logfile and the sapld hangs:

Jun  1 09:02:24 ldap-01 slapd[8836]: conn=633789 op=1 ADD
dn="cn=3,cn=2,cn=node,cn=1,cn=BBB,cn=AAA,cn=companies,ou=root"
Jun  1 09:02:24 ldap-01 slapd[8836]: => bdb_idl_insert_key: c_get
failed: DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock (-30995)
Jun  1 09:02:24 ldap-01 slapd[8836]: => bdb_dn2id_add 0x205e7e:
subtree (cn=BBB,cn=AAA,cn=companies,ou=root) insert failed: -30995

After this, I don't see any messages in the log till the staff was
initiating a stop/start:

Jun  1 09:09:29 ldap-01 slapd[8836]: daemon: shutdown requested and initiated.
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633113 fd=9 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=405426 fd=12 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633787 fd=13 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=1011 fd=14 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=1013 fd=18 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=632703 fd=33 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=632710 fd=37 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=632883 fd=39 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=632762 fd=40 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633211 fd=41 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633735 fd=45 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=632829 fd=47 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633170 fd=48 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633200 fd=50 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: conn=633788 fd=55 closed (slapd shutdown)
Jun  1 09:09:29 ldap-01 slapd[8836]: slapd shutdown: waiting for 22
operations/tasks to finish
Jun  1 09:09:42 ldap-01 slapd[20945]: @(#) $OpenLDAP: slapd 2.4.30 $
   opensuse-buildservice@opensuse.org
Jun  1 09:09:43 ldap-01 slapd[20945]: slapd starting

After the error message at 09:02:24 the slapd did not answer any request.
I cannot recover that problem in a test environment.

The server is running in a MM environment (two masters), and the
server gets 200-1200 search request/s
Because of this high rate, we set "loglevel 0". Since we updated the
slapd to 2.4.30 (from 2.4.28) the server crashes/hangs about on times
a week.
Because of this we set loglevel 256 back again.


Would be very nice, if I can fix the problem, please help.

Thanks in advance

Meike


PS:
The slapd is a modified, self compiled version because of larger IDL
with following changes:

openldap-2.4.30/servers/slapd/back-bdb/idl.h:
-#define	BDB_IDL_LOGN	16	/* DB_SIZE is 2^16, UM_SIZE is 2^17 */
+#define	BDB_IDL_LOGN	17	/* DB_SIZE is 2^17, UM_SIZE is 2^18 */

openldap-2.4.30/include/ldap_pvt_thread.h:
-#	define LDAP_PVT_THREAD_STACK_SIZE ( 1 * 1024 * 1024 * sizeof(void *) )
+#	define LDAP_PVT_THREAD_STACK_SIZE ( 2 * 1024 * 1024 * sizeof(void *) )

All tests where running well!