[Freeipa-users] 3/4 replica failure - unknown reasons why

[thierry bordaz]

On 11/11/2015 04:20 PM, Andrew Krause wrote:
> Yesterday I came in to 3 of my 4 freeipa replicas in an unusable state and replication was not connecting any of the hosts to each other.  My first/primary host was still servicing authentication requests, but the others were in varying states of usability.  I've investigated logs on all 4 nodes and the only thing I can see is messages like this from when the problem started until I restarted all 4 with ipactl stop/ipactl start:
>
> [09/Nov/2015:19:17:16 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:19:16 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:21:19 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:23:19 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:25:21 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:27:21 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:29:26 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:31:26 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:32:37 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc2papp08.somedomain.com" (abcloc2papp08:389): Warning: Attempting to release replica, but unable to receive endReplication extended operation response from the replica. Error -5 (Timed out)
> [09/Nov/2015:19:33:29 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:34:37 -0700] NSMMReplicationPlugin - agmt="cn=meToa.somedomain.com" (abcloc2papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:35:28 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc1papp08.somedomain.com" (abcloc1papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
> [09/Nov/2015:19:36:41 -0700] NSMMReplicationPlugin - agmt="cn=meToabcloc2papp08.somedomain.com" (abcloc2papp08:389): Unable to receive the response for a startReplication extended operation to consumer (Timed out). Will retry later.
>
>
> We've already looked into our network and there was no outage/interruption between sites during the timeframe in question.  The only corrective action that was taken was to restart each node.  Does anyone know any way I can investigate further what caused this issue?  I don't like giving "I don't know" answers for why replication stopped working and did not resume by itself.
>
Hi Andrew,

There are quite periodic (each min or couple of min) networking issues 
where the primary host fails to process the replication protocol with 
bcloc[12]papp08.
There may be problem with the 3rd replica but it is present in this 
portion of logs.
Most of the time it prevents primary master to establish a replication 
session so these replica are likely late.
The replicas are reachable but do not answer fast enough and the 
protocol times out.

Default replication timeout is 10m but can be tuned in each replica 
agreement nsds5ReplicaTimeout.
Is the value set ?

As it was working fine before, it would be interesting to check the 
replica logs (may be enable replication logging for them) when the 
timeout occurs.
Also, if the problem continue take periodic (under the 
nsds5ReplicaTimeout value) pstacks of the replica because there may be 
something that make them busy and unable to answer fast enough.

thanks
thierry
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