17

Let's say I'm using Amazon's EC2 load balancer. I have it hooked up to two instances (excuse me if my terminology isn't correct). What happens if the load balancer fails? Do both instances fail to work now?

Improve this question
2
  • 2
    Stuff explodes.
    – Josh K
    May 6, 2010 at 4:32
  • Quis custodiet ipsos custodes?
    – user61015
    Dec 2, 2010 at 4:50

2 Answers 2

Reset to default
29

Typically load balancers are clustered together into a high-availability pair.

If one load balancer fails, the secondary picks up the failure and becomes active. They have a heartbeat link between them that monitors status.

If all load balancers fail (or are accidentally misconfigured), servers down-stream are knocked offline until the problem is resolved, or you manually route around them.

Improve this answer
1
  • 2
    +1 I bet in general: Misconfiguration > Hardware + Software Failure
    – Kyle Brandt
    May 6, 2010 at 12:19
2

Yes if the load balancer instances both fail the service is essentially dead. Note that amazons uptime includes up to 4 hours of downtime a year (99.95%)

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .