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alexandre_girau's avatar
alexandre_girau
Icon for Altocumulus rankAltocumulus
Dec 22, 2017

Persistence issue with TCP

Hi all,   We have a very simple configuration where we have multiple node in a pool for a specific TCP protocol (port 6000). In front of F5 farm we have an additionnal network device who NAT sourc...
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  • alexandre_girau's avatar
    alexandre_girau
    Dec 29, 2017

    Ok, I finally fix it ^^

    The issue was because I created a pool with 4 members, 2 same IP but different service port, cause we have 2 versions who using different socket

    And I have 2 Virtual Services different (based on version) with an iRule different for each in order to select specific node with the target port. The irule was like this :

    when CLIENT_ACCEPTED {

set xxx_node1 "13.x.x.183"
set xxx_node2 "40.x.x.221"
set xxx_ppol "pool_vm_xxx_prod"
set xxx_port yyyy

if { ([LB::status pool $xxx_ppol member $xxx_node1 $xxx_port] eq "up") and ([LB::status pool $xxx_ppol member $xxx_node2 $xxx_port] eq "up") }
{
    node $xxx_node1 $xxx_port
    node $xxx_node2 $xxx_port
}
elseif { ([LB::status pool $xxx_ppol member $xxx_node1 $xxx_port] eq "up") and ([LB::status pool $xxx_ppol member $xxx_node2 $xxx_port] eq "down") }
{
    node $xxx_node1 $xxx_port
}
elseif { ([LB::status pool $xxx_ppol member $xxx_node1 $xxx_port] eq "down") and ([LB::status pool $xxx_ppol member $xxx_node2 $xxx_port] eq "up") }
{
    node $xxx_node2 $xxx_port
}
else
{
    log "Error : Pool $xxx_ppol is down"
}

    }

    Finally, I just recreate 2 new pool specific to each version and on my 2 VS I associate this new pool based on target version and deleted the associated iRule.

    And now, my traffic is correctly load balanced 😉

    Thanks to all who help me in this situation

    Have a nice day, Regards Alex

alexandre_girau's avatar
alexandre_girau
Icon for Altocumulus rankAltocumulus

Hi

 

Thank you for your response. The protocol used is a no-known, developed by a company (based on tcp socket). So I’m not sur how to reply you about l7 on this traffic.

 

But if I understand what you mean, I don’t have to use a VS with a standard type, correct ?

 

Leonardo_Souza's avatar
Leonardo_Souza
Icon for Cirrocumulus rankCirrocumulus
Dec 27, 2017

In that case, yes, you don't need persistence.

 

The TCP connection will continue open until something happens. That can be, the connection is closed, timeout, the server goes down, etc...

 

You can change the timeout in the TCP profile, the default is 300 seconds. Create a new profile based on the default TCP, and change idle timeout value.

 

There is also the action on service down that you can configure in the pool settings. Basically, what happens to a connection that is already open and the server is marked as down by the monitor.