Adding GSS on top of existing CSM deployment

[branfarm1]

Hi there,

I have an existing CSM deployment that is performing L4 load-balancing for a number of serverfarms. Each farm is presented as it's own VIP, so no VIP has multiple farms on different ports.

I'm trying to add a GSS in front of this and I'd like to be able to have the GSS read load information from the CSM.  To accomplish this I've enabled CAPP on my CSM, and created a shared Keepalive that points to one of the internal addresses for the CSM (not a VIP address).  I've assigned this shared keepalive to two Answers, providing the VIP address of the service, and performing KAL-AP keepalives by Tag value.  In my vserver I've added the 'domain <TAG>' and entered in the matching Tag on the KAL-AP KeepAlive section of the Answer setup screen.

With these steps completed, when I look at the Answer status under Monitoring > Answers > Answer Status,  the GSS always sees it as 'Offline (Load:255)'.  I've verified that the CAPP communication is successful by watching the stats on both the GSS Answer Keepalive stats page, and by the output of 'show mod csm x capp'.  It seems like the communication is working just fine.  Any ideas why the GSS isn't marking my Answers available?

I'm using GSS 3.2.0.0.15 and CSM 4.3(5).

Thanks in advance!

Brandon

[branfarm1]

In regards to the KAL-AP keepalives, do I need to configure a specific probe on the CSM to support these, or should enabling capp udp on the csm suffice?

Thanks,

Brandon

[chrhiggi]

Brandon-

All you really need on the CSM is the domain under the verserver, and capp udp with the appropriate parameters (basically whatver you have configured on your gss, mirror it under capp)

I would take a tcpdump on the GSS to verify that the GSS is recieving load variables back from the CSM - if it is not, double check the routing.

Chris

[branfarm1]

Hi Chris,

Thanks for the reply.  I ended up opening a TAC case to troubleshoot, and found I was running into the following bug:

CSCsi70659 CSM sends vserver load of 255 for KAL-AP by tag

Symptom:

When CAPP UDP is enabled on the CSM, the CSM will return a load of 255 for vservers that are being probed by a KAL-AP keepalive.

Workaround:

Perform a 'no inservice' followed by an 'inservice' on the vserver.

I executed the workaround and now my GSS is correctly pulling load information from the CSM.

Thanks,

Brandon