This just happened....

Tester: My cluster is not working properly!!!
Me: What's wrong?
Tester: I don't know. I've checked all the logs available on the entire cluster. All i know is that node 1 and 7 is broken.
*ssh into the cluster*
node1
# less /var/log/<affected application log>.log
*no errors here everything is working properly*
node7
# less /var/log/<affected application log>.log
*goes down to the bottom and scrolls up a few lines*
<insert massive error here>

Checked all the logs eh?