Does Applying an iRule cause an outage of the VIP?

Hi Jason,

 

 

I believe that when you add an iRule to a VIP, all existing connections are preserved. However, the events of the iRule are applied to all existing connections.

 

 

The main issue I've seen is run time errors occurring with existing connections if the iRule expects variables to exist that wouldn't have been created in iRule events which weren't triggered for the connection. If you're simply selecting a pool based on a header, I wouldn't expect any issues.

 

 

However, it's always good if you can schedule a change window when making changes. You could also test the iRule on a test VIP by running looping curl or apache bench (man ab) against the VIP while adding the iRule.

 

 

Aaron