Forum Discussion

matharau's avatar
matharau
Icon for Nimbostratus rankNimbostratus
Jul 07, 2023

Erro monitors F5 Big IP APM

Hey guys.

I'm experiencing a problem with the Monitors in my environment.

I'm on Version 16.1.3 using APM.

The Monitors settings seem OK but when we have some fluctuation in the network, the monitors go down and do not go up automatically.
It requires me to manually make a change to its configuration (such as switching from HTTP to icmp)

This brings a very big impact because we have hundreds of POOL and NODES in the Environment.

If anyone has gone through something similar and can share the solution we will be grateful.

event
monitor
  • whisperer's avatar
    whisperer
    Icon for MVP rankMVP
    Jul 07, 2023

    Read this carefully:

    https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-monitors-reference-12-0-0/2.html

    Check time until up, manual resume, ramp up time, etc. Also, be sure to check the timeout and monitor check settings.

    Finally, you are making a very very BAD assumption. Ping is not a good monitor. If a web server reboots, and even the BIG-IP has a web server, the device will respond to Ping way before it responds to HTTP. Why? Device is rebooting and the HTTP service has not yet started!!! So even if you have manually marked the server as up immediately via Ping, it doesn't mean the backend server is ready to accept HTTP connection and indeed the client may be experiencing an outage at that point.

    Nothing in life is quick, have patience 🙂

     

    • matharau's avatar
      matharau
      Icon for Nimbostratus rankNimbostratus
      Jul 07, 2023

      Many thanks for the reply.

      I think I wasn't very clear on the issue.

      So I'll give as an example
      I have an application that is with the MONITOR (TCP) when there is an oscillation in the network, this monitor drops and does not come back when the application returns (I have to manually) make any change in the Monitor to force it to respond with status ok

      • whisperer's avatar
        whisperer
        Icon for MVP rankMVP
        Jul 07, 2023

        You need to provide some more information my friend!

        - Can you post a screenshot and/or configuration snippet of the monitor?

        - Can you search /var/log/ltm and grep out the log entries for this particular monitor?

  • matharau's avatar
    matharau
    Icon for Nimbostratus rankNimbostratus
    Jul 10, 2023

    Thanks for the feedback

    I doubt if you can understand the problem I'm going through.

    I am sending the Print of the configuration, we are using the Default and we created one, in both the problem happens.

     

     

     

     

    • boneyard's avatar
      boneyard
      Icon for MVP rankMVP
      Jul 11, 2023

      Ok, yeah then you are right. What you see shouldn't happen.

      As also requested before, what does the /var/log/ltm show about this monitor. Do you see it go up there or also not?

      If not then it might be an issue between the BIG-IP and the server. Perhaps after the issue on the server the traffic gets lost. You would have to do a packetcapture on the server to determine that.

      All in all it might be easier to create a support ticket, F5 support can help with this things on your actual system.