Question: Unity Connection 10.5.2 Cluster Failover sequence

[tschafferx]

Hi Cisco community,

I was wondering how the publisher regains it's role after a secondary server took over the publisher role ("Change Server status" option activated) due to a failure of the publisher.

How does the secondary (now primary, publisher server) know that if the old publisher comes back online, to make himself the secondary again.

I was wondering because the secondary (now primary) assumes the role of the publisher for the time while it's peer the old publisher is down. Is there a certain value in the database, that tells the secondary (now primary) that it's peer is back up online and therefore has to change its role? Or does the old primary/publisher assumes the role as primary automatically again.

Thank you in advance.

[Jaime Valencia]

Read here

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/8x/cluster_administration/guide/8xcuccagx/8xcuccag020.html

[tschafferx]

Thanks Jaime! I only read the one for version 10.X (https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/10x/install_upgrade/guide/10xcuciumgx/10xcuciumg040.html).

It looks like the document was truncated in the newer version.

Maybe you could ask your colleagues to add it again because obviously it still works like that.

Thanks. :)

[Jaime Valencia]

Yeah, I don't know why they have that tendency to remove info which was on older docs in the new docs, when it's still applicable and important, and you need to go back to 8.x or 9.x docs to find it.

[Ratheesh Kumar]

Hi there

When one of the servers stops functioning (for example, when it is shut down for maintenance), the remaining server assumes responsibility for handling all incoming calls for the cluster. The remaining server also assumes responsibility for the database and message store, which are both replicated to the other server when the connection and its functionality are restored.

How ? Using the SRM Service 

The Connection Server Role Manager service sends a keep-alive events between the publisher and subscriber servers to confirm that the servers are functioning and connected. If one of the servers stops functioning or the connection between the servers is lost, the Connection Server Role Manager service waits for the keep-alive events and may require 30 to 60 seconds to detect that the other server is not available. While the Connection Server Role Manager service is waiting for the keep-alive events, users signing in to the server with Secondary status will not be able to access their mailbox or send messages, because the Connection Server Role Manager service has not yet detected that the server with Primary status (which has the active message store) is unavailable. In this situation, callers who attempt to leave a message may hear dead air or may not hear the recording beep.

Hope this Helps

Cheers
Rath!

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