[Freeipa-users] replica DS failure deadlock

Ludwig Krispenz lkrispen at redhat.com
Wed Oct 19 08:13:26 UTC 2016


On 10/18/2016 08:52 PM, Andrew E. Bruno wrote:
> We had one of our replicas fail today with the following errors:
>
>
> [18/Oct/2016:13:40:47 -0400] agmt="cn=meTosrv-m14-32.cbls.ccr.buffalo.edu" (srv-m14-32:389) - Can't locate CSN 58065ef3000100030000 in the changelog (DB rc=-30988). If replication stops, the consumer may need to be reinitialized.
> [18/Oct/2016:13:43:07 -0400] NSMMReplicationPlugin - changelog program - _cl5WriteOperationTxn: retry (49) the transaction (csn=58065f74000500040000) failed (rc=-30993 (BDB0068 DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock))
> [18/Oct/2016:13:43:07 -0400] NSMMReplicationPlugin - changelog program - _cl5WriteOperationTxn: failed to write entry with csn (58065f74000500040000); db error - -30993 BDB0068 DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock
> [18/Oct/2016:13:43:07 -0400] NSMMReplicationPlugin - write_changelog_and_ruv: can't add a change for uid=janedoe,cn=users,cn=accounts,dc=cbls,dc=ccr,dc=buffalo,dc=edu (uniqid: 939bca48-2ced11e5-ac0b8f7e-e0b1a377, optype: 64) to changelog csn 58065f74000500040000
> [18/Oct/2016:13:43:07 -0400] - SLAPI_PLUGIN_BE_TXN_POST_MODRDN_FN plugin returned error but did not set SLAPI_RESULT_CODE
> [18/Oct/2016:13:43:07 -0400] NSMMReplicationPlugin - process_postop: Failed to apply update (58065f74000500040000) error (1).  Aborting replication session(conn=1314106 op=1688559)
> [18/Oct/2016:13:43:12 -0400] - cos_cache_change_notify: modified entry is NULL--updating cache just in case
> [18/Oct/2016:13:43:12 -0400] - Skipping CoS Definition cn=Password Policy,cn=accounts,dc=cbls,dc=ccr,dc=buffalo,dc=edu--no CoS Templates found, which should be added before the CoS Definition.
> [18/Oct/2016:13:43:20 -0400] - Operation error fetching Null DN (4a729f9a-955a11e6-aaffa516-e778e883), error -30993.
> [18/Oct/2016:13:43:20 -0400] - dn2entry_ext: Failed to get id for changenumber=30856302,cn=changelog from entryrdn index (-30993)
> [18/Oct/2016:13:43:20 -0400] - Operation error fetching changenumber=30856302,cn=changelog (null), error -30993.
> [18/Oct/2016:13:43:20 -0400] DSRetroclPlugin - replog: an error occured while adding change number 30856302, dn = changenumber=30856302,cn=changelog: Operations error.
> [18/Oct/2016:13:43:20 -0400] retrocl-plugin - retrocl_postob: operation failure [1]
> [18/Oct/2016:13:43:20 -0400] NSMMReplicationPlugin - process_postop: Failed to apply update (58065f9f000000600000) error (1).  Aborting replication session(conn=1901274 op=5)
> [18/Oct/2016:13:43:24 -0400] - ldbm_back_seq deadlock retry BAD 1601, err=0 BDB0062 Successful return: 0
> [18/Oct/2016:13:43:25 -0400] NSMMReplicationPlugin - changelog program - _cl5WriteOperationTxn: retry (49) the transaction (csn=58065f7c000a00040000) failed (rc=-30993 (BDB0068 DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock))
> [18/Oct/2016:13:43:25 -0400] NSMMReplicationPlugin - changelog program - _cl5WriteOperationTxn: failed to write entry with csn (58065f7c000a00040000); db error - -30993 BDB0068 DB_LOCK_DEADLOCK: Locker killed to resolve a deadlock
> [18/Oct/2016:13:43:25 -0400] NSMMReplicationPlugin - write_changelog_and_ruv: can't add a change for uid=janedoe,cn=users,cn=accounts,dc=cbls,dc=ccr,dc=buffalo,dc=edu (uniqid: 4080421a-2d0211e5-ac0b8f7e-e0b1a377, optype: 64) to changelog csn 58065f7c000a00040000
>
>
> ns-slapd was hung so we restarted and now it's stuck and won't come back up. It
> hangs up here:
>
> [18/Oct/2016:14:12:31 -0400] - Skipping CoS Definition cn=Password Policy,cn=accounts,dc=cbls,dc=ccr,dc=buffalo,dc=edu--no CoS Templates found, which should be added before the CoS Definition.
> [18/Oct/2016:14:12:31 -0400] NSMMReplicationPlugin - changelog program - _cl5NewDBFile: PR_DeleteSemaphore: /var/lib/dirsrv/slapd-CBLS-CCR-BUFFALO-EDU/cldb/a32992ce-71b811e5-9d33a516-e778e883.sema; NSPR error - -5943
> [18/Oct/2016:14:12:32 -0400] NSMMReplicationPlugin - changelog program - _cl5NewDBFile: PR_DeleteSemaphore: /var/lib/dirsrv/slapd-CBLS-CCR-BUFFALO-EDU/cldb/986efe12-71b811e5-9d33a516-e778e883.sema; NSPR error - -5943
>
>
> Tried deleting the semaphore files and restarting but no luck. Attached
> is a stacktrace of the stuck ns-slapd process.
>
> Here's the versions were running:
>
> ipa-server-4.2.0-15.0.1.el7.centos.19.x86_64
> 389-ds-base-1.3.4.0-33.el7_2.x86_64
>
> FWIW, we were experimenting with the new life-cycle management features,
> specifically "preserved" users and deleted the user "janedoe" when this
> happened.  From the errors above looks like this host failed to
> replicate the change?  Not sure if this is related or not.
>
> Is it possible to recover the database? Thanks in advance for any pointers.
from the stack trace the process is not hanging, it is trying to 
recover. After a crash/kill  the changelog does not contai a RUV and it 
is reconstructed by reading all records in the changelog, if this is 
large it can take some time.
If you look at that part of the stack repeatedly,

#4  0x00007f4e88daeba5 in cl5DBData2Entry (data=<optimized out>, len=<optimized out>, entry=entry at entry=0x7ffff6598910) at ldap/servers/plugins/replication/cl5_api.c:2342
         rc = <optimized out>
         version = <optimized out>
         pos = 0x7f4e9839d091 ""
         strCSN = 0x0
         op = 0x7ffff6598980
         add_mods = 0x7f4e983a5e80
         rawDN = 0x7f4e98396e20 "fqdn=cpn-k08-29-02.cbls.ccr.buffalo.edu,cn=computers,cn=accounts,dc=cbls,dc=ccr,dc=buffalo,dc=edu"
         s = "\300\037>\230N\177\000\000@\210Y\366\377\177\000\000@\210Y\366\377"
#5  0x00007f4e88daf5d6 in _cl5GetNextEntry (entry=entry at entry=0x7ffff6598910, iterator=0x7f4e983a5e80) at ldap/servers/plugins/replication/cl5_api.c:5291
         rc = 0
         it = 0x7f4e983a5e80
         key = {data = 0x0, size = 21, ulen = 0, dlen = 0, doff = 0, app_data = 0x0, flags = 16}
         data = {data = 0x7f4e9839cff0, size = 335, ulen = 0, dlen = 0, doff = 0, app_data = 0x0, flags = 16}
#6  0x00007f4e88dafb34 in _cl5ConstructRUV (purge=1, obj=0x7f4e983e1fc0, replGen=0x7ffff6598910 "\200\211Y\366\377\177") at ldap/servers/plugins/replication/cl5_api.c:4306


you should see some progress in which entry is handled


>
>
> --Andrew
>
>
>

-- 
Red Hat GmbH, http://www.de.redhat.com/, Registered seat: Grasbrunn,
Commercial register: Amtsgericht Muenchen, HRB 153243,
Managing Directors: Charles Cachera, Michael Cunningham, Michael O'Neill, Eric Shander

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/freeipa-users/attachments/20161019/809b6909/attachment.htm>


More information about the Freeipa-users mailing list