[Freeipa-users] replica DS failure deadlock
Andrew E. Bruno
aebruno2 at buffalo.edu
Wed Oct 19 16:54:44 UTC 2016
On Wed, Oct 19, 2016 at 06:33:05PM +0200, thierry bordaz wrote:
>
>
> On 10/19/2016 03:48 PM, Andrew E. Bruno wrote:
> > On Wed, Oct 19, 2016 at 10:13:26AM +0200, Ludwig Krispenz wrote:
> > > 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
> > >
> > Ludwig, thanks very much for the help. As you pointed out just needed to let it
> > finish. ns-slapd eventually came back up once it finished reading the
> > changelog. Still seeing some errors related to the NSMMReplicationPlugin failed
> > to apply update and from the managed-entries-plugin. Can these safely be
> > ignored or are they indicative of a more serious problem?
>
> This is difficult to say the reason of managed entries messages.
> It says that the origin entry "uid=janedoe,cn=deleted
> users,cn=accounts,cn=provisioning,dc=cbls,dc=ccr,dc=buffalo,dc=edu"
> is still having a managed entry ('|mepManagedEntry') that is possibly
> something like
> '|cn=janedoe,cn=groups,cn=accounts,dc=cbls,dc=ccr,dc=buffalo,dc=edu".
>
> This is looking like a bug because user 'janedoe' being a preserved user, it
> should not have any reference to existing groups.
>
> Could you dump uid=janedoe entry:
> ldapsearch -D "cn=directory manager" -w xxxx -b ""uid=janedoe,cn=deleted
> users,cn=accounts,cn=provisioning,dc=cbls,dc=ccr,dc=buffalo,dc=edu"
> nscpentrywsi
Here's the entry for janedoe:
ldapsearch -Y GSSAPI -b "uid=janedoe,cn=deleted users,cn=accounts,cn=provisioning,dc=cbls,dc=ccr,dc=buffalo,dc=edu" nscpentrywsi
# extended LDIF
#
# LDAPv3
# base <uid=janedoe,cn=deleted users,cn=accounts,cn=provisioning,dc=cbls,dc=ccr,dc=buffalo,dc=edu> with scope subtree
# filter: (objectclass=*)
# requesting: nscpentrywsi
#
# janedoe, deleted users, accounts, provisioning, cbls.ccr.buffalo.edu
dn: uid=janedoe,cn=deleted users,cn=accounts,cn=provisioning,dc=cbls,dc=ccr,d
c=buffalo,dc=edu
# search result
search: 4
result: 0 Success
# numResponses: 2
# numEntries: 1
>
> If the link still exists, it is looking like a bug but IMHO it should not
> create security issue.
>
> regards
> thierry
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