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edgranados_1975's avatar
edgranados_1975
Icon for Nimbostratus rankNimbostratus
Jan 23, 2018

Predictive member issue

Customer has a pool using 2 members and using Predictive member as LB mode. We are detecting that only one of the pool members is taking all the connections and making their server to increase their memory and cpu utilization during a long period of time. Right now application is working properly and I see that the VIP has a persistence source address profile of 60 minutes. If they take down the pool member the other one starts taking connections as normal. Is the pool working properly?

 

application delivery
LTM

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  • edgranados_1975's avatar
    edgranados_1975
    Icon for Nimbostratus rankNimbostratus
    Jan 23, 2018

    ltm virtual namezabbix.none.com_80 {

    destination 10.208.X.X:http
ip-protocol tcp
mask 255.255.255.255
persist {
    source_addr_60min {
        default yes
    }
}
pool namezabbix.pool_8080
profiles {
    tcp-lan-optimized { }
}

    ltm persistence source-addr source_addr_60min {

    defaults-from source_addr
map-proxies enabled
mask none
match-across-pools disabled
match-across-services disabled
match-across-virtuals disabled
mirror disabled
override-connection-limit disabled
timeout 3600

    ltm pool namezabbix.pool_8080 {

    load-balancing-mode predictive-member
members {
    10.216.X.X:webcache {
        priority-group 1
        session monitor-enabled
    }
    10.216.X.X:webcache {
        priority-group 2
        session monitor-enabled
    }
}
min-active-members 1
monitor http_200_response

    ltm monitor http http_200_response {

    defaults-from http interval 5 recv "HTTP/1.1 200 OK" send "GET / HTTP/1.1\nHost: \nConnection: Close\r\n\r\n" time-until-up 0 timeout 16

  • Ilian_Ivanov's avatar
    Ilian_Ivanov
    Icon for Nimbostratus rankNimbostratus
    Jan 23, 2018

    Hello,

     

    Looks like you have a proxy between your clients and F5. Maybe all connections comes from the same IP address and thats why you hit only one of the pool members.

     

    You can run a tcpdump to see if all clients comes from the same IP.

     

    If so, you can set a cookie persistence + http profile to solve the issue.

     

    Regards