Forum Discussion

Melissa_Good_10's avatar
Melissa_Good_10
Icon for Nimbostratus rankNimbostratus
Oct 31, 2013

Fall back host - how to find out what condition is causing it to invoke

I have a pair of 3900s running 11.2 code. I have a web application that takes requests from the internet using Akamai caching - after a recent code change we have seen a high rate of invokes of the ...
application delivery
availability
deployment
devops
iRules
What_Lies_Bene1's avatar
What_Lies_Bene1
Icon for Cirrostratus rankCirrostratus
Nov 01, 2013

You've a few options, assuming the fallback is specified in a HTTP profile;

 

1) Run a packet capture (as a background process) and write it to a file; inspect it closely with Wireshark or a packet analysis tool if you've one available.

 

2) Create an iRule which logs data under the LB_FAILED event. See here for info on some of the data you can collect and log: https://devcentral.f5.com/wiki/iRules.LB.ashx

 

BTW, what do you have configured for the Pool's Action on Service Down setting?