ACE Load lancing for various traffic pattern

sachin.patole · ‎01-24-2011

I have situation as where ACE is doing load balancing on 2 real servers for application traffic.

The requirement is that I want to use the same VIP & real server ( with same IP addresses ) for SFTP traffic.
But in this case I want to send traffic only 1 real server . In failure scenario when server 1 goes down traffic will be send to 2nd real server.( i.e. active /standby scenario).

Any suggestion how it can be done with affecting production application traffic ?

Regards
Sach

pablo.nxh · ‎01-24-2011

Hi Sachin,

If your current configuration is not using port translation under the serverfarm (rservers with specific port defined) then

you can use the same serverfarm for SFTP load balancing.

SFTP is just FTP over SSH so it's a straight configuration to load balance traffic on port 22.

You can try this config:

probe tcp SFTP
port 22
interval 5
faildetect 2
passdetect interval 5
passdetect count 2

serverfarm host SFARM2
probe SFTP
rserver FTP-1
   backup-rserver FTP-2
    inservice
rserver FTP-2
    inservice standby

class-map match-any VIP
2 match virtual-address 10.10.10.100 tcp eq 22

policy-map type loadbalance first-match SFTP
class class-default
serverfarm SFARM1

policy-map multi-match Current
class Current
    loadbalance vip inservice
    loadbalance policy SLB
    loadbalance vip icmp-reply active
class VIP
    loadbalance vip inservice
    loadbalance policy SFTP
    loadbalance vip icmp-reply active

HTH

__ __

Pablo

sachin.patole · ‎01-27-2011

Pablo,

Thanks for your reply.

As per your suggestion if 2nd server is inactive , so how it will carry traffic when 1st server goes down ?

~~Sachin

pablo.nxh · ‎01-27-2011

Hi Sachin,

If your primary rserver goes down due to probe failure all the connections associated with that server will be automatically flushed from the connection table so that all new incoming connections will be diverted to your backup rserver.

Once the primary rserver comes back online then:

- Existing connections on backup keep accessing backup till they're completed.

- If a new client request (connection) doesn't match any connection entry for backup rserver ACE forwards this request to primary.

Once all the current conns on backup rserver are closed it returns to standby state.

Hope this clears things up!

__ __

Pablo

sachin.patole · ‎02-07-2011

Hi Pablo,

I have following config for REAL server farm

serverfarm host OSBFARM
rserver osbpla01-app 8017
    probe HTTP_8017
    inservice
rserver osbpla01-app 8019
    probe HTTP_8019
    inservice
rserver osbpla02-app 8017
    probe HTTP_8017
    inservice
rserver osbpla02-app 8019
    probe HTTP_8019
    inservice

If I add following config under this server farm will it affect traffic for above config,

serverfarm host SFARM2
probe SFTP
rserver FTP-1
   backup-rserver FTP-2
    inservice
rserver FTP-2
    inservice standby

Regards

Sachin

pablo.nxh · ‎02-08-2011

Hi Sachin,

This should not affect your current SF configuration as this new serverfarm will be used under a different first-match service-policy regardless they use the same VIP address.

HTH

__ __

Pablo

Jorge Bejarano · ‎02-08-2011

Hi, Sachin

Additionally you can go ahead and check this link:

http://www.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA3_1_0/configuration/slb/guide/rsfarms.html#wp1000264

In case you want to configure a backup server to be activate when the primary server fails down.

Regards,

Jorge

http://www.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA3_1_0/configuration/slb/guide/rsfarms.html#wp1000264