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Magnum_IP's avatar
Magnum_IP
Icon for Nimbostratus rankNimbostratus
Feb 08, 2013

Splitting TCP payload and load balancing

I am receiving data over a single TCP connection which at present gets sent to one the the pool members in the pool attached to the VIP. The data received is actually a stream of identifiable chunks...
config
design
nitass's avatar
nitass
Icon for Employee rankEmployee
Feb 11, 2013
i did a bit test using \n as message boundary. client is netcat and server is echo streamserver. firstly i used 10.2.4 hf4 but having an issue about multiple messages per packet (e.g. 1\n2\n3\n). anyway, one message per packet (e.g. 1\n) seems okay.

i suspected it might be bug 383853. there is engineering hotfix available on 11.1.0 hf4, so i applied it and it seems a bit better. tcp::notify eom is command from the engineering hotfix. it is used to release parsed message. tcp::notify request/response is used in the past.

Bug 383853 - Need a synchronous event to signal end of message from TCP rule event

not sure if this is what you are looking for. anyway, this is my testing. hope it helps. 

root@ve11enghf(Active)(/Common)(tmos) show sys version| grep -i -A 3 product
  Product  BIG-IP
  Version  11.1.0
  Build    2185.38
  Edition  Engineering Hotfix HF4

root@ve11enghf(Active)(/Common)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.19.252:7
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        mblb { }
        tcp { }
    }
    rules {
        myrule
    }
    snat automap
    vlans-disabled
}
root@ve11enghf(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:7 {
            address 200.200.200.101
        }
        200.200.200.111:7 {
            address 200.200.200.111
        }
    }
}
root@ve11enghf(Active)(/Common)(tmos) list ltm rule myrule
ltm rule myrule {
    when CLIENT_ACCEPTED {
  log local0. "--"
  log local0. "[IP::client_addr]:[TCP::client_port] > [IP::local_addr]:[TCP::local_port]"
  TCP::collect
}
when CLIENT_DATA {
  set idx 1
  log local0. "--"
  log local0. "received [TCP::payload]"
  while {$idx <= [TCP::payload length]} {
    if {[TCP::payload $idx] ends_with "\n"} {
      log local0. "sent [TCP::payload $idx]"
      TCP::release $idx
      TCP::notify request
      TCP::notify eom
      set idx 1
    } else {
      incr idx
    }
  }
  TCP::collect
}
when SERVER_CONNECTED {
  log local0. "--"
  TCP::collect
}
when SERVER_DATA {
  set recvidx 1
  log local0. "--"
  log local0. "[IP::remote_addr]:[TCP::remote_port] > [IP::local_addr]:[TCP::local_port]"
  log local0. "received [TCP::payload]"
  while {$recvidx <= [TCP::payload length]} {
    if {[TCP::payload $recvidx] ends_with "\n"} {
      log local0. "sent [TCP::payload $recvidx]"
      TCP::release $recvidx
      TCP::notify response
      TCP::notify eom
      set recvidx 1
    } else {
      incr recvidx
    }
  }
  TCP::collect
}
}

 A. single message per packet

 clieint

[root@centos251 ~] nc 172.28.19.252 7
1 <--- (type in)
1 <--- (echo response)
2
2
3
3

 log

[root@ve11enghf:Active] config  tail -f /var/log/ltm
Feb 11 09:41:17 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:17 tmm info tmm[8822]: Rule /Common/myrule : 172.28.19.251:49509 > 172.28.19.252:7
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : received 1
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : sent 1
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : 200.200.200.111:7 > 200.200.200.10:49509
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : received 1
Feb 11 09:41:19 tmm info tmm[8822]: Rule /Common/myrule : sent 1
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : received 2
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : sent 2
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : 200.200.200.101:7 > 200.200.200.10:49509
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : received 2
Feb 11 09:41:20 tmm info tmm[8822]: Rule /Common/myrule : sent 2
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : received 3
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : sent 3
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : 200.200.200.111:7 > 200.200.200.10:49509
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : received 3
Feb 11 09:41:21 tmm info tmm[8822]: Rule /Common/myrule : sent 3


 B. multiple messages per packet

 client

[root@centos251 ~] cat data.txt
1
2
3
4
5
6
7
8
9
10

[root@centos251 ~] nc 172.28.19.252 7 < data.txt
2
4
6
8
10
1
3
5
7
9

 log

[root@ve11enghf:Active] config  tail -f /var/log/ltm
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : 172.28.19.251:49513 > 172.28.19.252:7
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : received 1 2 3 4 5 6 7 8 9 10
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 1
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 2
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 3
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 4
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 5
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 6
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 7
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 8
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 9
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 10
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : 200.200.200.111:7 > 200.200.200.10:49513
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : received 2 4 6 8 10
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 2
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 4
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 6
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 8
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 10
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : --
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : 200.200.200.101:7 > 200.200.200.10:49513
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : received 1 3 5 7 9
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 1
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 3
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 5
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 7
Feb 11 09:44:01 tmm info tmm[8822]: Rule /Common/myrule : sent 9