ACE 4710 - 'reverse proxy' infront of serverfarm - fail-over/sorry server design issue

[rhgtyink]

Hi All,

I'm working on a specific config and have an issue in the backup farm/fail-over/sorry server area.

The customer wants the following:

They have an existing serverfarm with X web servers, they want a single server to act as a reverse-proxy in front of the farm.

So that all traffic goes trough that server, that server then forwards the request to the original serverfarm.

The problem in my design is in the fail-over, if i configure the reverse-proxy server in a new serverfarm and use the original (web servers) farm as backup it has fail-over, but if the reverse-proxy AND the original serverfarm fail, there is no nice way to get the users on a sorry server.

I could give the original serverfarms rservers a 'backup standby' server but that won't give the desired effect either.

For maintance they first take 50% of the servers offline and switch to the other 50% after that, so then users would see a sorry page even if there where operational servers in the farm left.

The 4710's are running routed mode, and the farms use Sticky Cookie, and also some http URL & Cookie matching is done.

Anyone have an idea how to build this?

[ajayku2]

Hi,

You can even use something like this :

serverfarm host 1313-GIN-GWAP-SDC-80

  rserver RSERVER1

    backup-rserver test2

    inservice

  rserver test1

    inservice standby

  rserver test2

    inservice standby

So for every rserver you can configure multiple rserver as backup.

See if that can be something handy and helpful.

The other idea would be to add 1 more proxy server and distribute the servers in between them.

regards,

Ajay Kumar

[rhgtyink]

Hi Ajay,

Thanks for the response!

Can I also decide the order in which the backup servers are used?

e.g. the first backup server would be a server containing web content and the second fail would be a sorry server?

[ajayku2]

Hi,

It need additional testing but as per my understanding if you put the back up in this order then the last backup server will be choosen first.

In your case it will be like " RSERVER1 >> backup sorry server >> backup web content

As per the below example:

I put test 2 as first backup server and test1 as second backup server but if you look at the first part it took rserver test1 as first backup.

serverfarm host 1313-GIN-GWAP-SDC-80

  rserver RSERVER1

    backup-rserver test1

    inservice

  rserver test1

    inservice standby

  rserver test2

    inservice standby

regards,

Ajay Kumar

[rhgtyink]

Nice, I'll put that in my lab config and will feedback if it works as expected.

Only problem is that lab will not be available until start of march so it can take a while.

Thanks in advance!