Wrong Load reporting via KAL-AP form CSM to GSS

[yves.haemmerli]

When multiple virtual servers are configured on the same VIP (each using another TCP port), the CSM averages all the CAPP load values when reporting the final CAPP load to the GSS.

Unfortunately, when a redirect vserver is configured on the same VIP (i.e to redirect the user to another TCP port), the CAPP load value sent to the GSS is wrong. This is due to the fact that the redirection vserver has always a load value of 2! Therefore, even if all real servers of the server farm are down, the reported load value to the GSS is (255 + 2) / 2 = 128 instead of 255 (offline).

Why does the CSM take a redirection server farm into account when reporting the load value to the GSS ? What would be a work-around ?

Here is an extract of my configuration:

serverfarm REDIRECTION

nat server

no nat client

redirect-vserver REDIR-1

webhost relocation 10.10.10.111:26000/irj

inservice

!

serverfarm PORTAL

nat server

nat client NAT-MSSRTE

real 10.10.10.10

maxconns 200

minconns 100

inservice

real 10.10.10.11

maxconns 200

minconns 100

inservice

!

policy PORTAL-POLICY

sticky-group 1

serverfarm M-GLOBEPROD

!

policy REDIR-POLICY

url-map URL-1

serverfarm REDIRECTION

!

vserver PORTAL-VSERVER

virtual 141.122.88.87 tcp 26000

persistent rebalance

slb-policy PORTAL-POLICY

no inservice

!

vserver REDIRECT

virtual 141.122.88.87 tcp www

persistent rebalance

slb-policy REDIR-POLICY

inservice

!

[Gilles Dufour]

you should use kal-ap by tag instead of kal-ap by vip.

This will allow you to really select which vserver you want the load from.

Regards,

Gilles.

[yves.haemmerli]

Hi Gilles,

Thank you for your suggestion. I configured KAL-AP by Tag now, but the two VIP answers configured on the GSS remain in offline state. I didn't found any description on how to configure the counterpart tag string in the CSM vserver configuration (I suppose that the same tag must be configured on the GSS and on the CSM ?)

Can you help me ?

[Gilles Dufour · Accepted solution]

Yves,

the command is under the vserver and I believe it is 'domain '.

Gilles.

[yves.haemmerli]

Gilles,

Thank you very much for your support, it works now with the command Router(config-slb-vserver)# domain . May I suggest a GSS/CSM documentation improvement, in which more details could be given on the communication between the GSS and the CSM. In particular the usage of KAL-AP by VIP versus KAL-AP by Tag.

Thanks again

Yves