Commit 9d798870 authored by Jim Jagielski's avatar Jim Jagielski
Browse files

Add in a weighted byte count of all traffic (in and out) as 

an alternative balancing method. We do not "adjust" the
byte count wrt scheme or method, simply by factoring
in the lbfactor value.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@126304 13f79535-47bb-0310-9956-ffa450edef68
parent 02fe9bfd

CHANGES

+3 −0
Changes for CHANGES: 3 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -2,6 +2,9 @@ Changes with Apache 2.1.3 








  [Remove entries to the current 2.0 section below, when backported]

















  *) proxy_balancer: Add in load-balancing via weighted traffic









     byte count. [Jim Jagielski]

















  *) mod_disk_cache: Cache r->err_headers_out headers.  This allows CGI









     scripts to be properly cached.  [Justin Erenkrantz, Sander Striker]










































docs/manual/mod/mod_proxy.xml



+9
−2



























Changes for docs/manual/mod/mod_proxy.xml: 9 added lines, 2 removed lines.



Original line number
Diff line number
Diff line







@@ -443,8 +443,8 @@







    <tr><td>loadfactor</td>









        <td>1</td>









        <td>Worker load factor. Used with BalancerMember.









         It is a number between 1 and 100 and defines the load applied to









         the worker.









         It is a number between 1 and 100 and defines the normalized weighted









         load applied to the worker.









    </td></tr>









    <tr><td>route</td>









        <td>-</td>










@@ -472,6 +472,13 @@







    <tr><th>Parameter</th>









        <th>Default</th>









        <th>Description</th></tr>









    <tr><td>lbmethod</td>









        <td>-</td>









        <td>Balancer load-balance method. Select the load-balancing scheduler









        method to use. Either <code>requests</code>, to perform weighted









        request counting or <code>traffic</code>, to perform weighted









        traffic byte count balancing. Default is <code>requests</code>.









    </td></tr>









    <tr><td>stickysession</td>









        <td>-</td>









        <td>Balancer sticky session name. The value is usually set to something


































modules/proxy/mod_proxy.c



+15
−2



























Changes for modules/proxy/mod_proxy.c: 15 added lines, 2 removed lines.



Original line number
Diff line number
Diff line







@@ -253,6 +253,15 @@ static const char *set_balancer_param(apr_pool_t *p,







        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";









    }










@@ -1695,11 +1704,15 @@ static int proxy_status_hook(request_rec *r, int flags)







        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>"


































modules/proxy/mod_proxy.h



+4
−0



























Changes for modules/proxy/mod_proxy.h: 4 added lines, 0 removed lines.



Original line number
Diff line number
Diff line







@@ -292,6 +292,10 @@ struct proxy_balancer {







    apr_interval_time_t timeout; /* Timeout for waiting on free connection */









    int                 max_attempts; /* Number of attempts before failing */









    char                max_attempts_set;









    enum {









       lbmethod_requests = 1,









       lbmethod_traffic = 2









    } lbmethod;



















    /* XXX: Perhaps we will need the proc mutex too.









     * Altrough we are only using arithmetic operations


































modules/proxy/proxy_balancer.c



+106
−8



























Changes for modules/proxy/proxy_balancer.c: 106 added lines, 8 removed lines.



Original line number
Diff line number
Diff line







@@ -161,7 +161,7 @@ static proxy_worker *find_session_route(proxy_balancer *balancer,







}



















/*









 * 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".










@@ -205,7 +205,7 @@ static proxy_worker *find_session_route(proxy_balancer *balancer,







 *   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;










@@ -213,9 +213,6 @@ static proxy_worker *find_best_worker(proxy_balancer *balancer,







    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










@@ -241,11 +238,88 @@ static proxy_worker *find_best_worker(proxy_balancer *balancer,







    if (candidate) {









        candidate->s->lbstatus -= total_factor;









        candidate->s->elected++;









        PROXY_THREAD_UNLOCK(balancer);









    }



















    return candidate;









}









    else {



















/*









 * 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










@@ -522,6 +596,21 @@ static int balancer_handler(request_rec *r)







                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;










@@ -599,12 +688,15 @@ static int balancer_handler(request_rec *r)







                      "\">", 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>"










@@ -681,6 +773,12 @@ static int balancer_handler(request_rec *r)







            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,