Red Hat Bugzilla – Bug 474248
Replica crashes in the consumer initialization if the backend to be replicated does not exist
Last modified: 2015-01-04 18:35:14 EST
Steps to reproduce the problem
1. Set up replication (I used single master - single replica)
Both have the suffix "dc=example,dc=com"
2. Create a sub suffix ou=sub,dc=example,dc=com only on master
3. Create an agreement to replicate ou=sub,dc=example,dc=com
4. Initialize the replica, which crashes the replica
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x438c1950 (LWP 27456)]
0x0000003c1c880f80 in strlen () from /lib64/libc.so.6
#0 0x0000003c1c880f80 in strlen () from /lib64/libc.so.6
#1 0x00000000006d3afe in slapi_mtn_set_state (sdn=0x1d62680, state=0x0)
#2 0x00007f2c42084965 in repl_set_mtn_state_and_referrals (
repl_root_sdn=0x1d62680, mtn_state=0x0, ruv=0x0, ruv_referrals=0x0,
other_referrals=0x0) at ldap/servers/plugins/replication/replutil.c:764
#3 0x00007f2c42062495 in multimaster_extop_StartNSDS50ReplicationRequest (
pb=0x1de1c20) at ldap/servers/plugins/replication/repl_extop.c:841
#4 0x00000000006e2211 in plugin_call_exop_plugins (pb=0x1de1c20,
oid=0x1c26eb0 "2.16.840.1.1137188.8.131.52") at ldap/servers/slapd/plugin.c:393
#5 0x000000000041a453 in do_extended (pb=0x1de1c20)
#6 0x00000000004127f3 in connection_dispatch_operation (conn=0x7f2c3f587728,
op=0x1de60d0, pb=0x1de1c20) at ldap/servers/slapd/connection.c:560
#7 0x0000000000413d18 in connection_threadmain ()
#8 0x0000003c2c429aa3 in ?? () from /usr/lib64/libnspr4.so
#9 0x0000003c1d40729a in start_thread (arg=<value optimized out>)
#10 0x0000003c1c8e439d in clone () from /lib64/libc.so.6
Cause of the crase:
In the following code, slapi_mtn_get_state returns NULL since the mapping tree entry 'cn="ou=sub,dc=example,dc=com",cn=mapping tree,cn=config' does not exist on the Replica. At the line 835, slapi_start_bulk_import fails due to the same reason. In the error handling code, it tries to set the original state back even though the state does not exist. We should skip resetting the mapping tree state.
534 * This plugin entry point is called whenever a
535 * StartNSDS50ReplicationRequest is received.
538 multimaster_extop_StartNSDS50ReplicationRequest(Slapi_PBlock *pb)
814 char *mtnstate = slapi_mtn_get_state(repl_root_sdn);
815 char **mtnreferral = slapi_mtn_get_referral(repl_root_sdn);
833 /* start the bulk import */
834 slapi_pblock_set (pb, SLAPI_TARGET_DN, repl_root);
835 rc = slapi_start_bulk_import (pb);
836 if (rc != LDAP_SUCCESS)
838 response = NSDS50_REPL_INTERNAL_ERROR;
839 /* reset the mapping tree state to what it was before
840 we tried to do the bulk import */
841 repl_set_mtn_state_and_referrals(repl_root_sdn, mtnstate,
842 NULL, NULL, mtnreferral);
Created attachment 325451 [details]
cvs diff slapd/mapping_tree.c plugins/replication/repl_extop.c plugins/replication/replutil.c
. mapping_tree.c: if NULL mapping tree state is passed, return an error.
. repl_extop.c: if mapping tree node state is NULL, don't reset the mapping
. replutil.c: if NULL mapping tree state is passed, log it and return.
Created attachment 325616 [details]
cvs commit message
Reviewed by Nathan (Thank you!!)
Checked in into CVS HEAD.
Using the attached ldif file to initialize the consumer with backend done succeeded.
Completed with the following entry in the error log:
[07/Apr/2009:14:42:59 -0700] NSMMReplicationPlugin - agmt="cn=sub" (praseodymium:3660): Simple bind failed, LDAP sdk error 91 (Can't connect to the LDAP server), Netscape Portable Runtime error -5961 (TCP connection reset by peer.)
Created attachment 338616 [details]
ldif file used to populate dc=sub,dc=example,dc=com on the consumer before replication.
Not that this file is really necessary, but it's probably nice to have.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.