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OM's avatar
Icon for Nimbostratus rankNimbostratus
Jun 22, 2011

HTTP MONITORING with IIS restriction


Our IIS servers are configured such as no http requests based on ip address are accepted from the clients, hence, the LTM monitor always gets a 503 service unavailable when sending GET health check.




any idea or workaround for this?










6 Replies

  • nathe's avatar
    Icon for Cirrocumulus rankCirrocumulus



    That's an interesting one. In a custom http monitor you could set the receive string as "503 service unavailable" and then this would mark the monitor as UP. Bit of an odd monitor as an error code is going to mark the pool member as Active and can accept connections.



    Is that what you're after or have I mis-understood?



  • OM's avatar
    Icon for Nimbostratus rankNimbostratus
    well, the keepalive URI in the server is a script that checks other services and returns an HTTP 200 OK if it succeeds, therefore, I have no other choice than expecting the 200 OK string as a receive response.



    Currently, I am using the following, but it doesn't work:


    GET /keepalive.aspx\r\ \r\nConnection: Close\r\n



    any hint ?
  • Do you mean if the client ip is not unresolvable, IIS will return 503? If it is the case, you can try to add LTM IP's into IIS system's host file.
  • Good thought Moo. Another possibility is that the server sends a 503 if there is an IP in the host header value. But that should be solved by hardcoding a valid hostname in the monitor's send string.



  • OM's avatar
    Icon for Nimbostratus rankNimbostratus
    thanks Moo and Aaron,



    i finally hardcoded hostnames each monitor instance, and it works just fine.



    One more question, for the same website, I have 2 pools (http and https). Is it possible to use an http monitor for an https pool ?