Does LB_Failed have the same criteria as using an HTTP Fallback Host?

Hi Chris,

 

 

Trying to track down this needle in a haystack we're trying to completely understand when the fallback 302 would be sent, and it appears that it's exactly 100% of the same reasons the LB_FAILED event would fail.

 

 

I think that's correct.

 

 

an HTTP request IS made to a pool member and then has it's connection reset etc, would NOT cause the fallback host to kick in? Once a TCP connection is established to the member, both the even and the fallback redirect can never occur?

 

 

That's also correct. You can handle this failure scenario using the after command. You'd need to set a timeout in milliseconds to wait for a server response. If it doesn't come then you could send an HTTP response back to the client and/or log something. The second example on the after wiki page should be a good start:

 

 

http://devcentral.f5.com/wiki/iRules.after.ashx

 

 

I put in an RFE to support this type of response timeout in an HTTP profile. The ID is BZ373937. You could open a case with F5 Support to raise the visibility of the request.

 

 

Aaron