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HG
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Jan 05, 2016

Help with LTM Custom Health Monitor

Hi all,

 

Having a scenario where 2 virtual servers exist. The first virtual server listens to www.example.com and the second one to www.test.com. Both virtual servers have assigned the same pool with the same pool members A and B using round robbin load balancing. In other words both sites sit on both servers A and B. Currently the default http health monitor is in use but I would like to make the monitoring a little bit more specific by including a received string on the response. Could you please let me know if by adding on the received string example.com|test.com and leaving the default send string as GET /\r\n will have the expected results ?? I would like to add one monitor on this specific pool so as to monitor both application sites having as a parent profile the default HTTP. Is this the correct way to implement that ??

 

Thanks.

 

3 Replies

  • The Receive String needs to be set to something the application will produce in the response to the Send String request. The question is whether or not string "example.com" or "test.com" is something that the pool produces consistently in the content served by either site's default page (as specified by the GET/\r\n Send String). If the default page does not return either of these character strings anywhere in the HTTP response (headers or body), then the monitor will fail. The Receive String does not apply to what the client sends (as presented to the virtual server), it applies to what the server responds with, as requested by the monitor's Send String.

     

  • As you state that both pool members ('A' and 'B') are servicing both www.example.com and i assume you have virtual hosts etc configured. Can i suggest you try the following as a start

    Send:

    GET / HTTP/1.1\r\nHost: www.example.com\r\nConnection: Close\r\n\r\n
    

    Receive:

    200 OK
    

    (assuming your application responds with a '200 OK')

  • Thanks both for your answers. I will try and come back to you with the results. One more thing that I would like to ask you is if it is possible to make a health monitor sending out snmp info regarding the state of pool members ? In this case for example if the get message comes back with a non 200 response raise an alert.

     

    Thanks again