--On Thursday, September 01, 2016 7:52 AM +0000 quanah(a)openldap.org wrote:
Full_Name: Quanah Gibson-Mount
Version: OpenLDAP 2.4.44
OS: Linux 2.6
URL:
ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (75.111.52.177)
In a 2-node MMR setup. Node 1 is getting a lot of write traffic. Both
node 1 and node 2 have 3 replicas each. At some point, a change is
received by node 1, which writes the change to its accesslog DB and its
primary DB. It's 3 replicas are all correctly updated. MMR node 2
receives the change, updates its primary DB, but *fails* to write the
change to the accesslog DB. However, it *does* write the CSN update to
the accesslog DB successfully. This causes all of its replicas to also
update their CSN. Then a change comes in triggering a constraint
violation on the replicas, but fully accepted by their master.
So the above summary is incorrect. While 3 replicas did go out of sync...
2 belonged to the primary master (node1), and 1 belonged to the secondary
master (node 2). So really, 4 systems didn't log the change (MMR node 2,
ldap05, ldap07, ldap09).
So I have no explanation at the moment why ldap06, ldap08, and ldap10 were
not affected.
--Quanah
--
Quanah Gibson-Mount