· Feb 13, 2023

IRIS mirror - arbiter status


I have a IRIS mirror set

. all running on SUSE Linux

. each on a separate server

consisting of




My arbiter is the ISCagent.



Is there a Linux command showing me the status of the ISCagent as arbiter?

The systemctl service command below shows if the service is running but not if it is acting correctly as an arbiter.

I'm looking for a command like iris list which you can run on the Primary or Backup



systemctl list-units --type=service|grep -i isc
ISCAgent.service                                                                          loaded active running InterSystems Agent


Product version: IRIS 2022.2
Discussion (11)3
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I'm not sure I totally follow your architecture and why looking at the arbiter vs a failover member would be better. It would probably be good to discuss the details with your sales engineer (I'm guessing you're already speaking to them about this). Is the VIP not being handled automatically by the mirror? I saw you commented on some ZMIRROR related posts; I think that would be a good way for your mirror to kick off those non-IRIS failover items automatically on failover, rather than needing to poll.

I'm not aware of a sample in our modern documentation but I've put in a request for that. Since pretty much any arbitrary code can be run in ZMIRROR, I don't think there's much guideline for coding ZMIRROR besides the documented tags.

I do think that something like the stubs we document for ZSTART/ZSTOP might be helpful, if that's what you had in mind.

I would encourage you to review the loss of connectivity scenarios covered in our documentation. The arbiter disconnecting from both sides is not enough to trigger a hang.

A hang suggests a total loss of network connection between failover members and the arbiter simultaneously. In general, the arbiter is a supplement to the communication between the two failover members, and not necessarily the first place to look for an issue.

ex. If the arbiter connections to the failover members were first lost, the primary and failover member would remain in contact via their own ISCAgents. Then, if the two members lost contact with each other, the primary would have continued to operate.

I based my view on the logs I got from Node 1, Node 2 & arbiter and the timestamps.

These are some samples:


2023-01-17T15:54:56.773722+11:00 LIVEARB ISCAgent[16131]: Arbiter client error: Message read failed.

Node 1:

01/17/23-15:56:22:875 (18886) 2 [Utility.Event] Arbiter connection lost

01/17/23-15:56:23:663 (24774) 0 [Generic.Event] MirrorServer: Received new failover mode (Agent Controlled) from backup...(repeated 1 times)

Node 2:

01/17/23-15:56:23:407 (9272) 0 [Generic.Event] MirrorClient: Switched from Arbiter Controlled to Agent Controlled failover on request from primary