Forum Discussion

JSpartan0901_95's avatar
JSpartan0901_95
Icon for Nimbostratus rankNimbostratus
Feb 10, 2012

Routing traffic to all the pool members except one by keeping the existing load balancing algorithm

Hi all,

 

 

I would like to achieve the following in iRules. Appreciate if someone can help me suggest the right way.

 

 

Today, we already have a pool configured with Least connections (member) algorithm. Now we are planning to add another member to this pool and route traffic to it based on a value of certain cookie.

 

 

One way of doing this would be to create another pool with just the new member and write iRule -

 

 

If{ [string match "*[1]" [HTTP::cookie value "testCookie"]]}

 

{ pool existing_pool }

 

else

 

{ pool pool_with_only_one_new_member }

 

 

Is there a way I can achieve this by adding the new member to the existing pool?

 

 

If{ [string match "*[1]" [HTTP::cookie value "testCookie"]]}

 

{ pool existing_pool new_member_ip new_member_port }

 

else

 

{ pool existing_pool old members 1,2,3 }

 

 

Can we do this? If yes, how to ensure it still uses the least connections(member) algorithm?

 

What will be the correct syntax for mentioning three pool members.

 

 

-JS

 

 

 

 

application delivery
dev
devops
iRules
  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Feb 10, 2012
    is it something like this? 

    [root@ve1023:Active] config  b virtual bar list
bvirtual bar {
   snat automap
   pool foo
   destination 172.28.19.79:80
   ip protocol 6
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@ve1023:Active] config  b pool foo list
pool foo {
   lb method member least conn
   members {
      200.200.200.101:80 {}
      200.200.200.102:80 {}
      200.200.200.111:80 {}
   }
}
[root@ve1023:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
   set vs "[IP::local_addr]:[TCP::local_port]"

   if {[HTTP::cookie value "testCookie"] contains "111"} {
      pool foo member 200.200.200.111 80
   }
}

when HTTP_RESPONSE {
   log local0. "[IP::client_addr]:[TCP::client_port] -> $vs -> [IP::remote_addr]:[TCP::remote_port]"
}
}

[root@ve1023:Active] config  curl -I http://172.28.19.79
HTTP/1.1 200 OK
Date: Sat, 11 Feb 2012 01:02:12 GMT
Server: Apache/2.2.3 (CentOS)
Last-Modified: Fri, 11 Nov 2011 14:48:14 GMT
ETag: "4183e4-3e-9c564780"
Accept-Ranges: bytes
Content-Length: 62
Content-Type: text/html; charset=UTF-8

[root@ve1023:Active] config  curl -I http://172.28.19.79 -H "Cookie: testCookie=abc111"
HTTP/1.1 200 OK
Date: Sat, 11 Feb 2012 00:58:25 GMT
Server: Apache/2.2.3 (CentOS)
Last-Modified: Wed, 30 Nov 2011 05:42:33 GMT
ETag: "418416-30-33ce6440"
Accept-Ranges: bytes
Content-Length: 48
Connection: close
Content-Type: text/html; charset=UTF-8

[root@ve1023:Active] config  cat /var/log/ltm
Feb 10 16:55:34 local/tmm info tmm[4822]: Rule myrule : 172.28.19.80:51524 -> 172.28.19.79:80 -> 200.200.200.101:80
Feb 10 16:55:37 local/tmm info tmm[4822]: Rule myrule : 172.28.19.80:51525 -> 172.28.19.79:80 -> 200.200.200.111:80