Should I be using Full http monitoring or Simple http monitoring for health checks?
Posted on 2008-10-03
We recently upgraded from a Foundry load balancer which used simple health script checks to keep nodes in the pool to a Zeus Load Balancer which uses ping, the Zeus "Full HTTP" and a health script which is a .NET page which renders a simple "server up" message. Passive monitoring is turned OFF.
We have multiple issues but it basically comes down to this:
1. The Zeus will drop a node for whatever reason. In this mornings case - it was a timeout to the node it dropped
2. Our CDN all of a sudden can't get to orign
3. Our site's go down until we purge our CDN
This morning Zeus dropped one node but displayed the regrettable - "no suitable nodes available to service your request" But only one node was dropped.
There were no errors or problems on the box - no application or system events, no processor pegs, no memory pegs, but the box was unresponsive for whatever reason and the entire pool failed. 2 minutes later, the pool was back online and functioning properly with 2 nodes. We of course had to flush our CDN to get rid of the nodes message.
The question is this - Is "full http" too much monitoring for simple content and registration Web site?
Would Zeus' "simple http" be a better alternative, which would create fewer false positives with the nodes?
Any help would be appreciated!