ACE Backup-server failover

[gtochld11]

I'm having trouble with the functionality of backup servers in a serverfarm.

Lets say I have three rservers in a serverfarm. Each rserver has a backup-server assigned to it. When a probe detects that one of the three nodes failed, the ACE puts the backupserver in rotation for the whole serverfarm. This causes one out of three connections to show a "under construction" page. However two of the three nodes are still functioning, but users randomly see a construction page, which confuses them.

Is there a way to configure the ACE to follow this procedure?

• One server fails a probe, take server out of rotation
  
• Second server fails a probe, take server out of rotation
  
• Third server fails a probe, take server out of rotation
  
• Place backupserver in rotation for the whole farm
  
• When one server comes back online, put it inservice and take backupserver out of rotation.
  

The intent is for the rservers to be self-sufficient making server administrators not have to have any knowledge of ACE and need to login and manually place a serever out of service. I want a probe to detect IIS failing and allow server administrators to work on one node at a time without an outage, and still retain a construction page if all nodes fail.

[mgalazka]

It sounds like "sorry server" configuration is more of what you are looking for?  Please read the following link and see if it is more of what you are looking for:

http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/ace/vA5_1_0/configuration/slb/guide/classlb.html#wp1306327

When the primary server farm is unavailable, you can instruct the ACE to send client requests to a sorry server farm. A sorry server is a redirect server in a backup server farm with content stating that the web page, resource, or service that a client requested is temporarily unavailable. When at least one server in the primary server farm returns to service, the ACE directs clients back to the primary server farm.

Hope this helps!

Matt

[Jorge Bejarano]

Hi,

Probably, you may need a "sorry server" configuration but also there´s another way which you may take into account which backup serverfarm, please take a look:

http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/ace/vA5_1_0/configuration/slb/guide/classlb.html

"...

backup

name2

—(Optional)  Designates an existing host (with valid content) or a redirect (sorry)  server farm as a backup server farm in case all the real servers in the  primary server farm become unavailable. You can configure one backup  server farm for each existing primary server farm. When at least one  server in the primary server farm becomes available again, the ACE sends  all new connections back to the primary server farm. The ACE allows  existing connections to the backup server farm to complete."

Regards,

Jorge