4 ms·
You can configure a LB to inspect layer 7 - in HAProxy this is done with an observe directive. Error 500s would then take the member out of a pool. You are righ
by jeremyjh 14y ago
You can configure a LB to inspect layer 7 - in HAProxy this is done with an observe directive. Error 500s would then take the member out of a pool. You are right that the health check of a static file may put it right back into the pool, but you can give it a slow rise value so that it waits a few minutes to do that. I'm not saying this is easy to get right but it is definitely possible to at least reduce the frequency of selection of a server raising 500 errors.
- donavanm 14y agoYes, all things are possible. You'll also have to keep state and track rates. Otherwise a very low error rate could down all of your backend hosts. But you're now running a stateful l7 application proxy. That's waaaaaay more expensive than a tcp proxy with asynchronous checks.