balancer->max_attempts = ival;
balancer->max_attempts_set = 1;
}
+ else if (!strcasecmp(key, "lbmethod")) {
+ /* Which LB scheduler method */
+ if (!strcasecmp(val, "traffic"))
+ balancer->lbmethod = lbmethod_traffic;
+ else if (!strcasecmp(val, "requests"))
+ balancer->lbmethod = lbmethod_requests;
+ else
+ return "lbmethod must be Traffic|Requests";
+ }
else {
return "unknown Balancer parameter";
}
ap_rputs("<hr />\n<h1>Proxy LoadBalancer Status for ", r);
ap_rvputs(r, balancer->name, "</h1>\n\n", NULL);
ap_rputs("\n\n<table border=\"0\"><tr>"
- "<th>SSes</th><th>Timeout</th>"
+ "<th>SSes</th><th>Timeout</th><th>Method</th>"
"</tr>\n<tr>", r);
ap_rvputs(r, "<td>", balancer->sticky, NULL);
- ap_rprintf(r, "</td><td>%" APR_TIME_T_FMT "</td>\n",
+ ap_rprintf(r, "</td><td>%" APR_TIME_T_FMT "</td>",
apr_time_sec(balancer->timeout));
+ ap_rprintf(r, "<td>%s</td>\n",
+ balancer->lbmethod == lbmethod_requests ? "Requests" :
+ balancer->lbmethod == lbmethod_traffic ? "Traffic" :
+ "Unknown");
ap_rputs("</table>\n", r);
ap_rputs("\n\n<table border=\"0\"><tr>"
"<th>Sch</th><th>Host</th><th>Stat</th>"
}
/*
- * The idea behind this scheduler is the following:
+ * The idea behind the find_best_byrequests scheduler is the following:
*
* lbfactor is "how much we expect this worker to work", or "the worker's
* normalized work quota".
* b a d c d a c d b d ...
*
*/
-static proxy_worker *find_best_worker(proxy_balancer *balancer,
+static proxy_worker *find_best_byrequests(proxy_balancer *balancer,
request_rec *r)
{
int i;
proxy_worker *worker = (proxy_worker *)balancer->workers->elts;
proxy_worker *candidate = NULL;
- if (PROXY_THREAD_LOCK(balancer) != APR_SUCCESS)
- return NULL;
-
/* First try to see if we have available candidate */
for (i = 0; i < balancer->workers->nelts; i++) {
/* If the worker is in error state run
if (candidate) {
candidate->s->lbstatus -= total_factor;
candidate->s->elected++;
- PROXY_THREAD_UNLOCK(balancer);
- return candidate;
}
- else {
+
+ return candidate;
+}
+
+/*
+ * The idea behind the find_best_bytraffic scheduler is the following:
+ *
+ * We know the amount of traffic (bytes in and out) handled by each
+ * worker. We normalize that traffic by each workers' weight. So assuming
+ * a setup as below:
+ *
+ * worker a b c
+ * lbfactor 1 1 3
+ *
+ * the scheduler will allow worker c to handle 3 times the
+ * traffic of a and b. If each request/response results in the
+ * same amount of traffic, then c would be accessed 3 times as
+ * often as a or b. If, for example, a handled a request that
+ * resulted in a large i/o bytecount, then b and c would be
+ * chosen more often, to even things out.
+ */
+static proxy_worker *find_best_bytraffic(proxy_balancer *balancer,
+ request_rec *r)
+{
+ int i;
+ apr_off_t mytraffic = 0;
+ apr_off_t curmin = 0;
+ proxy_worker *worker = (proxy_worker *)balancer->workers->elts;
+ proxy_worker *candidate = NULL;
+
+ /* First try to see if we have available candidate */
+ for (i = 0; i < balancer->workers->nelts; i++) {
+ /* 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 (!candidate || mytraffic < curmin) {
+ candidate = worker;
+ curmin = mytraffic;
+ }
+ }
+ worker++;
+ }
+
+ if (candidate) {
+ candidate->s->elected++;
+ }
+
+ return candidate;
+}
+
+static proxy_worker *find_best_worker(proxy_balancer *balancer,
+ request_rec *r)
+{
+ proxy_worker *candidate = NULL;
+
+ if (PROXY_THREAD_LOCK(balancer) != APR_SUCCESS)
+ return NULL;
+
+ if (balancer->lbmethod == lbmethod_requests) {
+ candidate = find_best_byrequests(balancer, r);
+ } else if (balancer->lbmethod == lbmethod_traffic) {
+ candidate = find_best_bytraffic(balancer, r);
+ } else {
PROXY_THREAD_UNLOCK(balancer);
+ return NULL;
+ }
+
+ PROXY_THREAD_UNLOCK(balancer);
+
+ if (candidate == NULL) {
/* All the workers are in error state or disabled.
* If the balancer has a timeout sleep for a while
* and try again to find the worker. The chances are
bsel->max_attempts = ival;
bsel->max_attempts_set = 1;
}
+ if ((val = apr_table_get(params, "lm"))) {
+ int ival = atoi(val);
+ switch(ival) {
+ case 0:
+ break;
+ case lbmethod_traffic:
+ bsel->lbmethod = lbmethod_traffic;
+ break;
+ case lbmethod_requests:
+ bsel->lbmethod = lbmethod_requests;
+ break;
+ default:
+ break;
+ }
+ }
}
if (wsel) {
const char *val;
"\">", NULL);
ap_rvputs(r, balancer->name, "</a></h3>\n\n", NULL);
ap_rputs("\n\n<table border=\"0\"><tr>"
- "<th>StickySesion</th><th>Timeout</th><th>FailoverAttempts</th>"
+ "<th>StickySession</th><th>Timeout</th><th>FailoverAttempts</th><th>Method</th>"
"</tr>\n<tr>", r);
ap_rvputs(r, "<td>", balancer->sticky, NULL);
ap_rprintf(r, "</td><td>%" APR_TIME_T_FMT "</td>",
apr_time_sec(balancer->timeout));
ap_rprintf(r, "<td>%d</td>\n", balancer->max_attempts);
+ ap_rprintf(r, "<td>%s</td>\n",
+ balancer->lbmethod == lbmethod_requests ? "Requests" :
+ balancer->lbmethod == lbmethod_traffic ? "Traffic" : "Unknown");
ap_rputs("</table>\n", r);
ap_rputs("\n\n<table border=\"0\"><tr>"
"<th>Scheme</th><th>Host</th>"
ap_rputs("<tr><td>Failover Attempts:</td><td><input name=\"fa\" type=text ", r);
ap_rprintf(r, "value=\"%d\"></td></tr>\n",
bsel->max_attempts);
+ ap_rputs("<tr><td>LB Method:</td><td><select name=\"lm\">", r);
+ ap_rprintf(r, "<option value=\"%d\" %s>Requests</option>", lbmethod_requests,
+ bsel->lbmethod == lbmethod_requests ? "selected" : "");
+ ap_rprintf(r, "<option value=\"%d\" %s>Traffic</option>", lbmethod_traffic,
+ bsel->lbmethod == lbmethod_traffic ? "selected" : "");
+ ap_rputs("</select></td></tr>\n", r);
ap_rputs("<tr><td colspan=2><input type=submit value=\"Submit\"></td></tr>\n", r);
ap_rvputs(r, "</table>\n<input type=hidden name=\"b\" ", NULL);
ap_rvputs(r, "value=\"", bsel->name + sizeof("balancer://") - 1,
projects / apache / commitdiff