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kimhenriksen's avatar
kimhenriksen
Icon for Cirrostratus rankCirrostratus
Nov 16, 2022

Configuring a maintenance monitor for webservices

So.. We´ve setup a montior for a customer that check the content of a file to determine of the server should be Online / Offline. This file is edited manually so that they themselves can control the state of the pool member. 

I´ve tested both a standard https and a reverse, the reverse seems to fit the task.. except one thing, if the server that hosts the status files goes offline.. all servers in the pool go offline (and thats is a problem for both standard and reverse).. 

Anyone got any ides / tips / suggestions on how to accomplish something like this? 

We dont have a bigiq in place yet, we would like to avoid partitions as well... so something done without access to bigip/bigiq.

application delivery
  • Mohamed_Ahmed_Kansoh's avatar
    Mohamed_Ahmed_Kansoh
    Icon for MVP rankMVP
    Nov 16, 2022

    Hi kimhenriksen , 
     > If I understand you well , using Reverse option in your environment should not be fit , as reverse marks the pool member down if it matches with "the correct Receive string/content" , Reverse option is very useful for instance if you want to match with " ERROR 404 " so when the web page reurned " Error 404 " monitor marks pool member down. 

    > so explain , How do you configure Reverse monitor ? 
    Also clarify what is needed from F5 to match your needs ? 

  • kimhenriksen's avatar
    kimhenriksen
    Icon for Cirrostratus rankCirrostratus
    Nov 16, 2022

    Ok, so the way i´ve configured it in my lab is like this.

    I have a pool of 3 server, two monitors. One monitor checks the health of each member using a http header and that works very well. The second (the reverse monitor) checks that a status file (with an alias on the monitor to check it on another server, sort of a status mgmt server for the pool members) does not contain the string Maintenance, if it does it should be considered offline (not disabled) and a new member will be reselected. 

    But.. I wondered if it is possible to have it react only of the recieve string and sort of disable the timeout setting completly. This way i could hand over control of the pool to a party that doesnt have access to the ADC platform without the risk of losing the whole pool if the  status mgmt server went offline. 

    • Mohamed_Ahmed_Kansoh's avatar
      Mohamed_Ahmed_Kansoh
      Icon for MVP rankMVP
      Nov 16, 2022

      kimhenriksen , 
      For this inquiry : " But.. I wondered if it is possible to have it react only of the recieve string and sort of disable the timeout setting completly. This way i could hand over control of the pool to a party that doesnt have access to the ADC platform without the risk of losing the whole pool if the  status mgmt server went offline. " ) 
      Do you mean that you do not want to loose the avilabilty of pool if the " Reverse" monitor fails/down. 
      you mean that , it is of course doable. 

      - Another thing : 
      I understood from you that you want to prevent these users from modifying in " Content of file " that you are assigning your monitor. 

      - Or you can replace the two monitors by using this 

      Configure ( send string , Receive string and Recieve disable string as well ) 
      "Recieve disable string" means if this string returned from pool member , this monitor should be down. 

      I hope I could help.  

      • kimhenriksen's avatar
        kimhenriksen
        Icon for Cirrostratus rankCirrostratus
        Nov 16, 2022

        Ok, any tips on how the timeout disable is doable? I´ve yet to find a solution.

         

        Yes, if we comebine those two to one..  we´ll might get a problem with the Get URI.. they might have to be independent of each other. And the filecheck would be good if it could be done to another IP then the pool member. The customer want the member as standard as possible, but still have the possibility for online/offline. 

        But.. If the first part is solved, that solves all of it.