Forum Discussion

Aantat's avatar
Aantat
Icon for Cirrus rankCirrus
Jan 26, 2023

Losing Requests because of health monitoring

Hi team. I'm facing issue with losing requests because of health monitoring with a simple http application. When we have a unavailable pool member and after few seconds or minutes it becomes available we are losing 4-5 requests. Is there any tips to resolve my issue? My goal is don't lose any requests of clients. Also I thought about duplicate client requests to other node if the first one is not accepting client request. Is there any way to realize that? Any suggestions? Thanks in advance. 

application delivery
  • Paulius's avatar
    Paulius
    Jan 31, 2023

    Aantat I believe the issue you are experiencing is when your pool member is transitioning from green (healthy) to red (failed). These connections will always drop because the F5 still thinks the device is alive because the health monitor hasn't failed yet but is in the process of failing and I do not believe you can get around this at all other than the connections dropping because the F5 doesn't transition a client from one pool member to another until the health monitor fails completely.

  • Paulius's avatar
    Paulius
    Icon for MVP rankMVP
    Jan 26, 2023

    Aantat Can you go into a bit more depth on when the connections are being lost and share the configuration of the associated virtual servers and pools? Certain types of configuration will not automatically balance your connection to the next pool member without forming that initial connection to the new pool member first which sometimes does appear to be a lost request but most of the time unless a server requires persistence this goes unnoticed to the end user.

    • Aantat's avatar
      Aantat
      Icon for Cirrus rankCirrus
      Jan 31, 2023

      Hi Paulius 

      I'm losing that requests when node is going down. I confgirud "Action on service down" to Reselect, but I'm still losing 2-3 requests which is critical. My goal is IF one of the nodes is going down - requests goes to another node without losing that request. I hope I made it clear. Also there is no persistence

    • ashrafdawood's avatar
      ashrafdawood
      Icon for Nimbostratus rankNimbostratus
      Jan 27, 2023

      Hello Aantat 

       

       

      please make sure that your service is automatically going up when your server become up , this is setting on service tab on server , also there is seting to make service up when sytem become up 

    • Aantat's avatar
      Aantat
      Icon for Cirrus rankCirrus
      Jan 31, 2023

      Hi Hooni_L.

      I'm facing problem not when node becames available. I'm facing it when node is going down. I confgirud "Action on service down" to Reselect, but I'm still losing 2-3 requests which is critical. My goal is IF one of the nodes is going down - requests goes to another node without losing that request. I hope I made it clear

       

      • Paulius's avatar
        Paulius
        Icon for MVP rankMVP
        Jan 31, 2023

        Aantat I believe the issue you are experiencing is when your pool member is transitioning from green (healthy) to red (failed). These connections will always drop because the F5 still thinks the device is alive because the health monitor hasn't failed yet but is in the process of failing and I do not believe you can get around this at all other than the connections dropping because the F5 doesn't transition a client from one pool member to another until the health monitor fails completely.