I have a 2 node(node A and B) cluster with exact same specs. When I failover to node B application performance is really bad while everything work fine on node A. I tried and installed windows updates. Nothing... By the way it takes 4X longer to patch Node B. Any ideas? Thank you!
Assuming the hardware specs are identical, you need to look to the software. Differences in installed software, settings on the server, things along these lines. Also look to the wait statistics on each server through sys.dm_os_wait_stats to understand what is slowing things down. You'll need to capture i/o, cpu and memory metrics too. You need to understand what is performing badly in order to understand what to fix.