Dynamic switching of requesting between pools

Hello Sandesh,

 

 

A web browser will not send any arbitrary HTTP header it receives in a response in subsequent requests to the server, so 3 won't work exactly as you've described.

 

 

You could use any type of persistence on the VIP and then when you are ready to upgrade one server in the pool, mark the node down (set it to: 'Only active connections allowed'). While the node is marked down, it will receive no new TCP connections. Once you've upgraded the software on that node and you are ready to upgrade the second server, enable the first node and change the second node's status to 'Only persistent or active connections allowed'. This ensures that clients who make a request with a persistence record pointing to the first node will continue to be persisted there. Once all connections to the second node are closed, change the status to 'Only active connections allowed'. Once the second node has been upgraded, enable it once more.

 

 

You could build this same logic in an iRule, but the default configuration options are much easier to implement.

 

 

Aaron