We have a XenServer pool consisting of two Dell R410's running XenServer 5.6. The servers are connected to a few iSCSI NAS devices.

Lately, as I've been looking at the /var/log/messages I've been seeing a lot of this:

Apr 6 12:01:27 xenserver-alpha xapi: [error|xenserver-alpha|345 xal_listen|Event thread updating guest metrics (domid: 87) D:7cfbb800692e|sql] Duplicate key in set or map: table VM; field platform; ref OpaqueRef:b6808180-fabd-07c7-d19c-df3e345e8854; key viridian

I'm not sure what this error message means. I've seen it on both XenServers (lets call them xenserver-alpha and xenserver-beta).

Googling as brought me a few posts on the XenServer forums, but none of them seem to answer my question, which is:

What does this error mean?

Should I be concerned about it?

How do I fix it?