How do I detect if a pool is down in an iRule?

Thanks for the suggestion.

Actually I do have that in my production iRule. I just was looking for a way to handle the period where a server crashes or is otherwise unresponsive between the time a request is dispatched to it and before the health check marks a server as down.

There are still other active pool members in this scenario so if it would be possible to have the request redirected to another server, that would be even better. I already tried something like..

when HTTP_REQUEST {
   set request [HTTP::request]
}
when LB_FAILED {
   HTTP::retry $request
}

But I haven't gotten it to work yet.

-Al