On 07/31/2006 09:53 PM, Jim Jagielski wrote:
> Ruediger Pluem wrote:
>
>>
>>Shouldn't that be "while (cur_lbset <= max_lbset && !mycandidate);"
>>(same question also for the other algorithm)?
>>I guess otherwise we would not check for the workers with the lbset max_lbset.
>>
>
>
> No, since we do the test at the end, after we've incremented.
> If the current set is 3 and the max is 3, we want to stop.
Maybe I am confused, but we have not run the loop with current set 3 as we have
just incremented
at at the end.
So I try an example (maybe I prove myself wrong and make a fool out of me, but
that would help also :-)
Let's assume the maximum lbset is 1
1. We start the outer while loop with cur_lbset and max_lbset 0
2. In the inner while loop
1. we iterate over all workers of the balancer, but consider only those
who are not standby and who have an lbset of 0
2. we iterate over all workers of the balancer, but consider only those
who are standby and who have an lbset of 0
3. Now we leave the inner while loop and lets assume that we found no candidate
4. Now we increase cur_lbset to 1
5. Now we have to leave the outer while loop, because cur_lbset < max_lbset is
not true because cur_lbset = max_lbset
So we did not check for the workers with lbset 1.
BTW: Don't we need to reset checked_standby and checking_standby to zero in
the outer while loop?
+ do {
+ while (!mycandidate && !checked_standby) {
+ worker = (proxy_worker *)balancer->workers->elts;
+ for (i = 0; i < balancer->workers->nelts; i++, worker++) {
+ if (!checking_standby) { /* first time through */
+ if (worker->s->lbset > max_lbset)
+ max_lbset = worker->s->lbset;
+ }
+ if (worker->s->lbset > cur_lbset)
+ continue;
+ if ( (checking_standby ? !PROXY_WORKER_IS_STANDBY(worker) :
PROXY_WORKER_IS_STANDBY(worker)) )
+ continue;
+ /* If the worker is in error state run
+ * retry on that worker. It will be marked as
+ * operational if the retry timeout is elapsed.
+ * The worker might still be unusable, but we try
+ * anyway.
+ */
+ if (!PROXY_WORKER_IS_USABLE(worker))
+ ap_proxy_retry_worker("BALANCER", worker, r->server);
+ /* Take into calculation only the workers that are
+ * not in error state or not disabled.
+ */
+ if (PROXY_WORKER_IS_USABLE(worker)) {
+ mytraffic = (worker->s->transferred/worker->s->lbfactor) +
+ (worker->s->read/worker->s->lbfactor);
+ if (!mycandidate || mytraffic < curmin) {
+ mycandidate = worker;
+ curmin = mytraffic;
+ }
}
}
+ checked_standby = checking_standby++;
}
- checked_standby = checking_standby++;
- }
+ cur_lbset++;
+ } while (cur_lbset < max_lbset && !mycandidate);
Regards
Rüdiger
