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HTTP health checks failing for real server "Bad HTTP Status" when proper response code should be returned





HTTP health checks failing for real server


Product: LoadMaster

Version: Any

Platform: Any

Question/Problem Description:

Failing health check, but proper response code is being returned.

Steps to Reproduce:  
Error Message: "Bad HTTP status 404 Not Found."
Defect Number:  
Enhancement Number:  
Cause: The LoadMaster was attempting to reach out for the HTTP/HTTPS health check using the IP of the server instead of the hostname binding that the server is configured to answer for.


  1. First, lower the health checks to TCP Connection Only to at least verify network connectivity between the loadmaster and server.
  2. Next, change the health check to "HTTP" or "HTTPS" depending on if SSL is being utilized.
  3. If the virtual service reverts to a "down" status, this means the real server health check is failing. Take a look at the system message log file under System Configuration > Logging Options > System Log Files. Search for the server IP address, and any "Bad HTTP status" error logs.
  4. This error log will either indicate that the server itself is responding back to the loadmaster with an invalid HTTP response, which would need to be investigated, OR the correct hostname needs to be used for the health check.
  5. To determine if the server is responding with an invalid HTTP response, attempt to connect to the server directly and observe what status code it gives back.
  6. If there server is responding with a valid HTTP response code, for example, a 200 OK, then enable the HTTP/1.1 host option for the real server checks, and added the relevant hostname of the server for the loadmaster to check against.HTTPHost.jpg
  7. After doing this, the server should now pass its health check as expected.

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