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cjunior_138458
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Mar 02, 2015

Connection Limit Issue

Hi, I have an issue in the connection limit configuration of a pool. The pool members are getting new connections even with the connection limit reached. Analysing the LTM log, the pool is marked down when all members reached their limit, but still, you can see in the statistics that members received more connections than they should. I tried the known issues in version 11.4.1 HF4, but do not know if I missed some trick to make it work properly. Could anyone tell me if there is any specific configuration for the number of connections does not receive more connections than desired?

 

I appreciate any tips, tks.

 

10 Replies

  • Does the virtual service have a persistence method applied, and is the 'Override Connection Limit' option enabled for that persistence method? What type of virtual is configured?

     

    Just to clarify, you're seeing the number of current sessions or max sessions exceeds the connection limit? By how much do they exceed the limit?

     

  • Hi Summers,

     

    The VS do not have persistence. The problem happened at a time away from troubleshooting. We just realized the values in the pool statistics. The limit was 100 and reached 185 at one of the four members.

     

    We tried to reproduce the issue and we could not. The configuration is working well, wich is odd. I opened a ticket in support for this case but no conclusive solution. I will apply the hotfix and expect to happen again.

     

  • I didn't have chance to apply the hotfix and do not know if this will solve. Unfortunately the problem still occurs. One of the pool members shows 107 affected connections. I see this value in the maximum number of connections.

     

    I appreciate any suggestions.

     

  • The problem occurred again and I could see in time. When the problem first happened, I made some adjustments and now I'm using OnConnect mask 32. In the list of connections appeared many connections originating any6.any, and found SOL13850 to issue ID 284910. My VS is a standard so do not seem to make much sense what the SOL explains. I think I'll do the SOL workaround and see the result.

     

    Any idea?

     

  • is there any special configuration such as irule?

    can you post the configuration?

     tmsh list ltm virtual (name)
     tmsh list ltm pool (name)
     tmsh list ltm profile (type) (name)
     tmsh list ltm rule (name)
    
  • Hi nitass, there's nothing unusual in this VS. What I have realized is that always the last two members are beyond the limit.

        ltm virtual my_virtual_server {
        destination 1.1.1.26:http
        ip-protocol tcp
        mask 255.255.255.255
        pool my_pool
        profiles {
            http { }
            oneconnect_mask32 { }
            tcp { }
        }
        source 0.0.0.0/0
        source-address-translation {
            type automap
        }
        vlans {
            internal_vlan
        }
        vlans-enabled
        vs-index 36
    }
    
    ltm pool my_pool {
        load-balancing-mode least-connections-member
        members {
            1.1.1.254:ups-onlinet {
                address 1.1.1.254
                connection-limit 100
                session monitor-enabled
                state up
            }
            1.1.1.9:ups-onlinet {
                address 1.1.1.9
                connection-limit 100
                session monitor-enabled
                state up
            }
            1.1.1.217:ups-onlinet {
                address 1.1.1.217
                connection-limit 100
                session monitor-enabled
                state up
            }
            1.1.1.218:ups-onlinet {
                address 1.1.1.218
                connection-limit 100
                session monitor-enabled
                state up
            }
        }
        monitor http_monitor
        service-down-action reset
    }
    
    ltm profile one-connect oneconnect_mask32 {
        app-service none
        defaults-from oneconnect
        source-mask 255.255.255.255
    }
    
  • there's nothing unusual in this VS.

     

    yes, it looks straightforward configuration.

     

    have you ever tried another load balancing algorithm?

     

  • Hello nitass, You may be right, I just saw that the two items that seem to always present problem, are shared in another pool with another balancing method. I'll change to "least connections node" and wait and see. Thx

     

  • Hi, can you tell me when have more connections from the server side than client side?

     

    If my oneconnect profile is based on mask 32, I understand that the excess connections are IP that are no longer connected to the VS, is that right?

     

    I changed now the oneconnect max age to 30 minutes and I kept the idle tcp in 5 minutes.

     

    I appreciate any tips.