granicus.if.org Git - apache/blob - modules/proxy/proxy_balancer.c

   1 /* Copyright 1999-2004 The Apache Software Foundation
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 /* Load balancer module for Apache proxy */
  17
  18 #define CORE_PRIVATE
  19
  20 #include "mod_proxy.h"
  21 #include "ap_mpm.h"
  22 #include "scoreboard.h"
  23 #include "apr_version.h"
  24
  25 module AP_MODULE_DECLARE_DATA proxy_balancer_module;
  26
  27 #if APR_HAS_THREADS
  28 #define PROXY_BALANCER_LOCK(b)      apr_thread_mutex_lock((b)->mutex)
  29 #define PROXY_BALANCER_UNLOCK(b)    apr_thread_mutex_unlock((b)->mutex)
  30 #else
  31 #define PROXY_BALANCER_LOCK(b)      APR_SUCCESS
  32 #define PROXY_BALANCER_UNLOCK(b)    APR_SUCCESS
  33 #endif
  34
  35 static int init_runtime_score(apr_pool_t *pool, proxy_balancer *balancer)
  36 {
  37     int i;
  38     double median, ffactor = 0.0;
  39     proxy_runtime_worker *workers;
  40 #if PROXY_HAS_SCOREBOARD
  41     lb_score *score;
  42     int mpm_daemons;
  43 #else
  44     void *score;
  45 #endif
  46
  47     workers = (proxy_runtime_worker *)balancer->workers->elts;
  48
  49     for (i = 0; i < balancer->workers->nelts; i++) {
  50 #if PROXY_HAS_SCOREBOARD
  51         ap_mpm_query(AP_MPMQ_HARD_LIMIT_DAEMONS, &mpm_daemons);
  52         /* Check if we are prefork or single child */
  53         if (workers[i].w->hmax && mpm_daemons > 1) {
  54             score = ap_get_scoreboard_lb(getpid(), workers[i].id);
  55         }
  56         else
  57 #endif
  58         {
  59             /* Use the plain memory */
  60             score = apr_pcalloc(pool, sizeof(proxy_runtime_stat));
  61         }
  62         workers[i].s = (proxy_runtime_stat *)score;
  63     }
  64
  65     /* Recalculate lbfactors */
  66     for (i = 0; i < balancer->workers->nelts; i++) {
  67         /* Set to the original configuration */
  68         workers[i].s->lbfactor = workers[i].w->lbfactor;
  69         ffactor += workers[i].s->lbfactor;
  70     }
  71     if (ffactor < 100.0) {
  72         int z = 0;
  73         for (i = 0; i < balancer->workers->nelts; i++) {
  74             if (workers[i].s->lbfactor == 0.0)
  75                 ++z;
  76         }
  77         if (z) {
  78             median = (100.0 - ffactor) / z;
  79             for (i = 0; i < balancer->workers->nelts; i++) {
  80                 if (workers[i].s->lbfactor == 0.0)
  81                     workers[i].s->lbfactor = median;
  82             }
  83         }
  84         else {
  85             median = (100.0 - ffactor) / balancer->workers->nelts;
  86             for (i = 0; i < balancer->workers->nelts; i++)
  87                 workers[i].s->lbfactor += median;
  88         }
  89     }
  90     else if (ffactor > 100.0) {
  91         median = (ffactor - 100.0) / balancer->workers->nelts;
  92         for (i = 0; i < balancer->workers->nelts; i++) {
  93             if (workers[i].s->lbfactor > median)
  94                 workers[i].s->lbfactor -= median;
  95         }
  96     }
  97     for (i = 0; i < balancer->workers->nelts; i++) {
  98         /* Update the status entires */
  99         workers[i].s->lbstatus = workers[i].s->lbfactor;
 100     }
 101     balancer->status = 1;
 102     return 0;
 103 }
 104
 105 /* Retrieve the parameter with the given name                                */
 106 static char *get_path_param(apr_pool_t *pool, char *url,
 107                             const char *name)
 108 {
 109     char *path = NULL;
 110
 111     for (path = strstr(url, name); path; path = strstr(path + 1, name)) {
 112         path += (strlen(name) + 1);
 113         if (*path == '=') {
 114             /*
 115              * Session path was found, get it's value
 116              */
 117             ++path;
 118             if (strlen(path)) {
 119                 char *q;
 120                 path = apr_pstrdup(pool, path);
 121                 if ((q = strchr(path, '?')))
 122                     *q = '\0';
 123                 return path;
 124             }
 125         }
 126     }
 127     return NULL;
 128 }
 129
 130 static char *get_cookie_param(request_rec *r, const char *name)
 131 {
 132     const char *cookies;
 133     const char *start_cookie;
 134
 135     if ((cookies = apr_table_get(r->headers_in, "Cookie"))) {
 136         for (start_cookie = ap_strstr_c(cookies, name); start_cookie;
 137              start_cookie = ap_strstr_c(start_cookie + 1, name)) {
 138             if (start_cookie == cookies ||
 139                 start_cookie[-1] == ';' ||
 140                 start_cookie[-1] == ',' ||
 141                 isspace(start_cookie[-1])) {
 142
 143                 start_cookie += strlen(name);
 144                 while(*start_cookie && isspace(*start_cookie))
 145                     ++start_cookie;
 146                 if (*start_cookie == '=' && start_cookie[1]) {
 147                     /*
 148                      * Session cookie was found, get it's value
 149                      */
 150                     char *end_cookie, *cookie;
 151                     ++start_cookie;
 152                     cookie = apr_pstrdup(r->pool, start_cookie);
 153                     if ((end_cookie = strchr(cookie, ';')) != NULL)
 154                         *end_cookie = '\0';
 155                     if((end_cookie = strchr(cookie, ',')) != NULL)
 156                         *end_cookie = '\0';
 157                     return cookie;
 158                 }
 159             }
 160         }
 161     }
 162     return NULL;
 163 }
 164
 165 static proxy_runtime_worker *find_route_worker(proxy_balancer *balancer,
 166                                                const char *route)
 167 {
 168     int i;
 169     proxy_runtime_worker *worker = (proxy_runtime_worker *)balancer->workers->elts;
 170     for (i = 0; i < balancer->workers->nelts; i++) {
 171         if (worker->w->route && strcmp(worker->w->route, route) == 0) {
 172             return worker;
 173         }
 174         worker++;
 175     }
 176     return NULL;
 177 }
 178
 179 static proxy_runtime_worker *find_session_route(proxy_balancer *balancer,
 180                                                 request_rec *r,
 181                                                 char **route,
 182                                                 char **url)
 183 {
 184     if (!balancer->sticky)
 185         return NULL;
 186     /* Try to find the sticky route inside url */
 187     *route = get_path_param(r->pool, *url, balancer->sticky);
 188     if (!*route)
 189         *route = get_cookie_param(r, balancer->sticky);
 190     if (*route) {
 191         proxy_runtime_worker *worker =  find_route_worker(balancer, *route);
 192         /* TODO: make worker status codes */
 193         /* See if we have a redirection route */
 194         if (worker && !PROXY_WORKER_IS_USABLE(worker->w)) {
 195             if (worker->w->redirect)
 196                 worker = find_route_worker(balancer, worker->w->redirect);
 197             /* Check if the redirect worker is usable */
 198             if (worker && !PROXY_WORKER_IS_USABLE(worker->w))
 199                 worker = NULL;
 200         }
 201         else
 202             worker = NULL;
 203         return worker;
 204     }
 205     else
 206         return NULL;
 207 }
 208
 209 static proxy_runtime_worker *find_best_worker(proxy_balancer *balancer,
 210                                               request_rec *r)
 211 {
 212     int i;
 213     double total_factor = 0.0;
 214     proxy_runtime_worker *worker = (proxy_runtime_worker *)balancer->workers->elts;
 215     proxy_runtime_worker *candidate = NULL;
 216
 217     /* First try to see if we have available candidate */
 218     for (i = 0; i < balancer->workers->nelts; i++) {
 219         /* See if the retry timeout is ellapsed
 220          * for the workers flagged as IN_ERROR
 221          */
 222         if (!PROXY_WORKER_IS_USABLE(worker->w))
 223             ap_proxy_retry_worker("BALANCER", worker->w, r->server);
 224         /* If the worker is not in error state
 225          * or not disabled.
 226          */
 227         if (PROXY_WORKER_IS_USABLE(worker->w)) {
 228             if (!candidate)
 229                 candidate = worker;
 230             else {
 231                 /* See if the worker has a larger number of free channels */
 232                 if (worker->w->cp->nfree > candidate->w->cp->nfree)
 233                     candidate = worker;
 234             }
 235             /* Total factor should allways be 100.
 236              * This is for cases when worker is in error state.
 237              * It will force the even request distribution
 238              */
 239             total_factor += worker->s->lbfactor;
 240         }
 241         worker++;
 242     }
 243     if (!candidate) {
 244         /* All the workers are in error state or disabled.
 245          * If the balancer has a timeout wait.
 246          */
 247 #if APR_HAS_THREADS
 248         if (balancer->timeout) {
 249             /* XXX: This can perhaps be build using some
 250              * smarter mechanism, like tread_cond.
 251              * But since the statuses can came from
 252              * different childs, use the provided algo.
 253              */
 254             apr_interval_time_t timeout = balancer->timeout;
 255             apr_interval_time_t step, tval = 0;
 256             balancer->timeout = 0;
 257             step = timeout / 100;
 258             while (tval < timeout) {
 259                 apr_sleep(step);
 260                 /* Try again */
 261                 if ((candidate = find_best_worker(balancer, r)))
 262                     break;
 263                 tval += step;
 264             }
 265             /* restore the timeout */
 266             balancer->timeout = timeout;
 267         }
 268 #endif
 269     }
 270     else {
 271         /* We have at least one candidate that is not in
 272          * error state or disabled.
 273          * Now calculate the appropriate one
 274          */
 275         worker = (proxy_runtime_worker *)balancer->workers->elts;
 276         for (i = 0; i < balancer->workers->nelts; i++) {
 277             /* If the worker is not error state
 278              * or not in disabled mode
 279              */
 280             if (PROXY_WORKER_IS_USABLE(worker->w)) {
 281                 /* 1. Find the worker with higher lbstatus.
 282                  * Lbstatus is of higher importance then
 283                  * the number of empty slots.
 284                  */
 285                 if (worker->s->lbstatus > candidate->s->lbstatus) {
 286                     candidate = worker;
 287                 }
 288             }
 289             worker++;
 290         }
 291         worker = (proxy_runtime_worker *)balancer->workers->elts;
 292         for (i = 0; i < balancer->workers->nelts; i++) {
 293             /* If the worker is not error state
 294              * or not in disabled mode
 295              */
 296             if (PROXY_WORKER_IS_USABLE(worker->w)) {
 297                 /* XXX: The lbfactor can be update using bytes transfered
 298                  * Right now, use the round-robin scheme
 299                  */
 300                 worker->s->lbstatus += worker->s->lbfactor;
 301                 if (worker->s->lbstatus >= total_factor)
 302                     worker->s->lbstatus = worker->s->lbfactor;
 303             }
 304             worker++;
 305         }
 306     }
 307     return candidate;
 308 }
 309
 310 static int rewrite_url(request_rec *r, proxy_worker *worker,
 311                         char **url)
 312 {
 313     const char *scheme = strstr(*url, "://");
 314     const char *path = NULL;
 315
 316     if (scheme)
 317         path = ap_strchr_c(scheme + 3, '/');
 318
 319     /* we break the URL into host, port, uri */
 320     if (!worker) {
 321         return ap_proxyerror(r, HTTP_BAD_REQUEST, apr_pstrcat(r->pool,
 322                              "missing worker. URI cannot be parsed: ", *url,
 323                              NULL));
 324     }
 325
 326     *url = apr_pstrcat(r->pool, worker->name, path, NULL);
 327
 328     return OK;
 329 }
 330
 331 static int proxy_balancer_pre_request(proxy_worker **worker,
 332                                       proxy_balancer **balancer,
 333                                       request_rec *r,
 334                                       proxy_server_conf *conf, char **url)
 335 {
 336     int access_status;
 337     proxy_runtime_worker *runtime;
 338     char *route;
 339     apr_status_t rv;
 340
 341     *worker = NULL;
 342     /* Step 1: check if the url is for us */
 343     if (!(*balancer = ap_proxy_get_balancer(r->pool, conf, *url)))
 344         return DECLINED;
 345
 346     /* Initialize shared scoreboard data */
 347     if (!((*balancer)->status))
 348         init_runtime_score(conf->pool, *balancer);
 349
 350     /* Step 2: find the session route */
 351
 352     runtime = find_session_route(*balancer, r, &route, url);
 353     if (!runtime) {
 354         if (route && (*balancer)->sticky_force) {
 355             ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
 356                          "proxy: BALANCER: (%s). All workers are in error state for route (%s)",
 357                          (*balancer)->name, route);
 358             return HTTP_SERVICE_UNAVAILABLE;
 359         }
 360     }
 361     else {
 362         int i;
 363         proxy_runtime_worker *workers;
 364         /* We have a sticky load balancer */
 365         runtime->s->elected++;
 366         *worker = runtime->w;
 367         /* Update the workers status
 368          * so that even session routes get
 369          * into account.
 370          */
 371         workers = (proxy_runtime_worker *)(*balancer)->workers->elts;
 372         for (i = 0; i < (*balancer)->workers->nelts; i++) {
 373             /* For now assume that all workers are OK */
 374             workers->s->lbstatus += workers->s->lbfactor;
 375             if (workers->s->lbstatus >= 100.0)
 376                 workers->s->lbstatus = workers->s->lbfactor;
 377             workers++;
 378         }
 379     }
 380     /* Lock the LoadBalancer
 381      * XXX: perhaps we need the process lock here
 382      */
 383     if ((rv = PROXY_BALANCER_LOCK(*balancer)) != APR_SUCCESS) {
 384         ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
 385                      "proxy: BALANCER: lock");
 386         return DECLINED;
 387     }
 388     if (!*worker) {
 389         runtime = find_best_worker(*balancer, r);
 390         if (!runtime) {
 391             ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
 392                          "proxy: BALANCER: (%s). All workers are in error state",
 393                          (*balancer)->name);
 394
 395             PROXY_BALANCER_UNLOCK(*balancer);
 396             return HTTP_SERVICE_UNAVAILABLE;
 397         }
 398         runtime->s->elected++;
 399         *worker = runtime->w;
 400     }
 401     /* Decrease the free channels number */
 402     /* XXX: This should be the function of apr_reslist */
 403     --(*worker)->cp->nfree;
 404
 405     PROXY_BALANCER_UNLOCK(*balancer);
 406
 407     access_status = rewrite_url(r, *worker, url);
 408     /* Add the session route to request notes if present */
 409     if (route) {
 410         apr_table_setn(r->notes, "session-sticky", (*balancer)->sticky);
 411         apr_table_setn(r->notes, "session-route", route);
 412     }
 413     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
 414                  "proxy_balancer_pre_request rewriting to %s", *url);
 415     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
 416                  "proxy_balancer_pre_request worker (%s) free %d",
 417                  (*worker)->name,
 418                  (*worker)->cp->nfree);
 419
 420     return access_status;
 421 }
 422
 423 static int proxy_balancer_post_request(proxy_worker *worker,
 424                                        proxy_balancer *balancer,
 425                                        request_rec *r,
 426                                        proxy_server_conf *conf)
 427 {
 428     apr_status_t rv;
 429
 430     if ((rv = PROXY_BALANCER_LOCK(balancer)) != APR_SUCCESS) {
 431         ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
 432             "proxy: BALANCER: lock");
 433         return HTTP_INTERNAL_SERVER_ERROR;
 434     }
 435     /* increase the free channels number */
 436     worker->cp->nfree++;
 437     /* TODO: calculate the bytes transfered */
 438
 439     /* TODO: update the scoreboard status */
 440
 441     PROXY_BALANCER_UNLOCK(balancer);
 442     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
 443                  "proxy_balancer_post_request for (%s)", balancer->name);
 444
 445     return OK;
 446 }
 447
 448 static void recalc_factors(proxy_balancer *balancer,
 449                            proxy_runtime_worker *fixed)
 450 {
 451     int i;
 452     double median, ffactor = 0.0;
 453     proxy_runtime_worker *workers;
 454
 455
 456     /* Recalculate lbfactors */
 457     workers = (proxy_runtime_worker *)balancer->workers->elts;
 458     /* Special case if there is only one worker it's
 459      * load factor will always be 100
 460      */
 461     if (balancer->workers->nelts == 1) {
 462         workers->s->lbstatus = workers->s->lbfactor = 100.0;
 463         return;
 464     }
 465     for (i = 0; i < balancer->workers->nelts; i++) {
 466         if (workers[i].s->lbfactor > 100.0)
 467             workers[i].s->lbfactor = 100.0;
 468         ffactor += workers[i].s->lbfactor;
 469     }
 470     if (ffactor < 100.0) {
 471         median = (100.0 - ffactor) / (balancer->workers->nelts - 1);
 472         for (i = 0; i < balancer->workers->nelts; i++) {
 473             if (&(workers[i]) != fixed)
 474                 workers[i].s->lbfactor += median;
 475         }
 476     }
 477     else if (fixed->s->lbfactor < 100.0) {
 478         median = (ffactor - 100.0) / (balancer->workers->nelts - 1);
 479         for (i = 0; i < balancer->workers->nelts; i++) {
 480             if (workers[i].s->lbfactor > median &&
 481                 &(workers[i]) != fixed)
 482                 workers[i].s->lbfactor -= median;
 483         }
 484     }
 485     else {
 486         median = (ffactor - 100.0) / balancer->workers->nelts;
 487         for (i = 0; i < balancer->workers->nelts; i++) {
 488             workers[i].s->lbfactor -= median;
 489         }
 490     }
 491     for (i = 0; i < balancer->workers->nelts; i++) {
 492         /* Update the status entires */
 493         workers[i].s->lbstatus = workers[i].s->lbfactor;
 494     }
 495 }
 496
 497 /* Invoke handler */
 498 static int balancer_handler(request_rec *r)
 499 {
 500     void *sconf = r->server->module_config;
 501     proxy_server_conf *conf = (proxy_server_conf *)
 502         ap_get_module_config(sconf, &proxy_module);
 503     proxy_balancer *balancer, *bsel = NULL;
 504     proxy_runtime_worker *worker, *wsel = NULL;
 505     apr_table_t *params = apr_table_make(r->pool, 10);
 506     int access_status;
 507     int i, n;
 508     const char *name;
 509
 510     /* is this for us? */
 511     if (strcmp(r->handler, "balancer-manager"))
 512         return DECLINED;
 513     r->allowed = (AP_METHOD_BIT << M_GET);
 514     if (r->method_number != M_GET)
 515         return DECLINED;
 516
 517     if (r->args) {
 518         char *args = apr_pstrdup(r->pool, r->args);
 519         char *tok, *val;
 520         while (args && *args) {
 521             if ((val = ap_strchr(args, '='))) {
 522                 *val++ = '\0';
 523                 if ((tok = ap_strchr(val, '&')))
 524                     *tok++ = '\0';
 525                 if ((access_status = ap_unescape_url(val)) != OK)
 526                     return access_status;
 527                 apr_table_setn(params, args, val);
 528                 args = tok;
 529             }
 530             else
 531                 return HTTP_BAD_REQUEST;
 532         }
 533     }
 534     if ((name = apr_table_get(params, "b")))
 535         bsel = ap_proxy_get_balancer(r->pool, conf,
 536             apr_pstrcat(r->pool, "balancer://", name, NULL));
 537     if ((name = apr_table_get(params, "w"))) {
 538         const char *sc = apr_table_get(params, "s");
 539         char *asname = NULL;
 540         proxy_worker *ws = NULL;
 541         if (sc) {
 542             asname = apr_pstrcat(r->pool, sc, "://", name, NULL);
 543             ws = ap_proxy_get_worker(r->pool, conf, asname);
 544         }
 545         if (ws) {
 546             worker = (proxy_runtime_worker *)bsel->workers->elts;
 547             for (n = 0; n < bsel->workers->nelts; n++) {
 548                 if (strcasecmp(worker->w->name, ws->name) == 0) {
 549                     wsel = worker;
 550                     break;
 551                 }
 552                 ++worker;
 553             }
 554         }
 555     }
 556     /* First set the params */
 557     if (bsel) {
 558         const char *val;
 559         if (!bsel->status)
 560             init_runtime_score(conf->pool, bsel);
 561
 562         if ((val = apr_table_get(params, "ss"))) {
 563             if (strlen(val))
 564                 bsel->sticky = apr_pstrdup(conf->pool, val);
 565             else
 566                 bsel->sticky = NULL;
 567         }
 568         if ((val = apr_table_get(params, "tm"))) {
 569             int ival = atoi(val);
 570             if (ival >= 0)
 571                 bsel->timeout = apr_time_from_sec(ival);
 572         }
 573     }
 574     if (wsel) {
 575         const char *val;
 576         if ((val = apr_table_get(params, "lf"))) {
 577             char *ep;
 578             double dval = strtod(val, &ep);
 579             if (dval > 1) {
 580                 wsel->s->lbfactor = dval;
 581                 if (bsel)
 582                     recalc_factors(bsel, wsel);
 583             }
 584         }
 585         if ((val = apr_table_get(params, "wr"))) {
 586             if (strlen(val))
 587                 wsel->w->route = apr_pstrdup(conf->pool, val);
 588             else
 589                 wsel->w->route = NULL;
 590         }
 591         if ((val = apr_table_get(params, "rr"))) {
 592             if (strlen(val))
 593                 wsel->w->redirect = apr_pstrdup(conf->pool, val);
 594             else
 595                 wsel->w->redirect = NULL;
 596         }
 597         if ((val = apr_table_get(params, "dw")))
 598             wsel->w->status |= PROXY_WORKER_DISABLED;
 599         else
 600             wsel->w->status &= ~PROXY_WORKER_DISABLED;
 601
 602     }
 603     if (apr_table_get(params, "xml")) {
 604         ap_set_content_type(r, "text/xml");
 605         ap_rputs("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n", r);
 606         ap_rputs("<httpd:manager xmlns:httpd=\"http://httpd.apache.org\">\n", r);
 607         ap_rputs("  <httpd:balancers>\n", r);
 608         balancer = (proxy_balancer *)conf->balancers->elts;
 609         for (i = 0; i < conf->balancers->nelts; i++) {
 610             ap_rputs("    <httpd:balancer>\n", r);
 611             ap_rvputs(r, "      <httpd:name>", balancer->name, "</httpd:name>\n", NULL);
 612             ap_rputs("      <httpd:workers>\n", r);
 613             worker = (proxy_runtime_worker *)balancer->workers->elts;
 614             for (n = 0; n < balancer->workers->nelts; n++) {
 615                 ap_rputs("        <httpd:worker>\n", r);
 616                 ap_rvputs(r, "          <httpd:scheme>", worker->w->scheme,
 617                           "</httpd:scheme>\n", NULL);
 618                 ap_rvputs(r, "          <httpd:hostname>", worker->w->hostname,
 619                           "</httpd:hostname>\n", NULL);
 620                ap_rprintf(r, "          <httpd:loadfactor>%.2f</httpd:loadfactor>\n",
 621                           worker->s->lbfactor);
 622                 ap_rputs("        </httpd:worker>\n", r);
 623                 ++worker;
 624             }
 625             ap_rputs("      </httpd:workers>\n", r);
 626             ap_rputs("    </httpd:balancer>\n", r);
 627             ++balancer;
 628         }
 629         ap_rputs("  </httpd:balancers>\n", r);
 630         ap_rputs("</httpd:manager>", r);
 631     }
 632     else {
 633         ap_set_content_type(r, "text/html");
 634         ap_rputs(DOCTYPE_HTML_3_2
 635                  "<html><head><title>Balancer Manager</title></head>\n", r);
 636         ap_rputs("<body><h1>Load Balancer Manager for ", r);
 637         ap_rvputs(r, ap_get_server_name(r), "</h1>\n\n", NULL);
 638         ap_rvputs(r, "<dl><dt>Server Version: ",
 639                   ap_get_server_version(), "</dt>\n", NULL);
 640         ap_rvputs(r, "<dt>Server Built: ",
 641                   ap_get_server_built(), "\n</dt></dl>\n", NULL);
 642         balancer = (proxy_balancer *)conf->balancers->elts;
 643         for (i = 0; i < conf->balancers->nelts; i++) {
 644             if (!balancer->status)
 645                 init_runtime_score(conf->pool, balancer);
 646
 647             ap_rputs("<hr />\n<h3>LoadBalancer Status for ", r);
 648             ap_rvputs(r, "<a href=\"", r->uri, "?b=",
 649                       balancer->name + sizeof("balancer://") - 1,
 650                       "\">", NULL);
 651             ap_rvputs(r, balancer->name, "</a></h3>\n\n", NULL);
 652             ap_rputs("\n\n<table border=\"0\"><tr>"
 653                 "<th>StickySesion</th><th>Timeout</th>"
 654                 "</tr>\n<tr>", r);
 655             ap_rvputs(r, "<td>", balancer->sticky, NULL);
 656             ap_rprintf(r, "</td><td>%" APR_TIME_T_FMT "</td>\n",
 657                 apr_time_sec(balancer->timeout));
 658             ap_rputs("</table>\n", r);
 659             ap_rputs("\n\n<table border=\"0\"><tr>"
 660                 "<th>Scheme</th><th>Host</th>"
 661                 "<th>Route</th><th>RouteRedir</th>"
 662                 "<th>Factor</th><th>Status</th>"
 663                 "</tr>\n", r);
 664
 665             worker = (proxy_runtime_worker *)balancer->workers->elts;
 666             for (n = 0; n < balancer->workers->nelts; n++) {
 667
 668                 ap_rvputs(r, "<tr>\n<td>", worker->w->scheme, "</td><td>", NULL);
 669                 ap_rvputs(r, "<a href=\"", r->uri, "?b=",
 670                           balancer->name + sizeof("balancer://") - 1,
 671                           "&s=", worker->w->scheme, "&w=", worker->w->hostname,
 672                           "\">", NULL);
 673                 ap_rvputs(r, worker->w->hostname, "</a></td>", NULL);
 674                 ap_rvputs(r, "<td>", worker->w->route, NULL);
 675                 ap_rvputs(r, "</td><td>", worker->w->redirect, NULL);
 676                 ap_rprintf(r, "</td><td>%.2f</td><td>", worker->s->lbfactor);
 677                 if (worker->w->status & PROXY_WORKER_DISABLED)
 678                     ap_rputs("Dis", r);
 679                 else if (worker->w->status & PROXY_WORKER_IN_ERROR)
 680                     ap_rputs("Err", r);
 681                 else if (worker->w->status & PROXY_WORKER_INITIALIZED)
 682                     ap_rputs("Ok", r);
 683                 else
 684                     ap_rputs("-", r);
 685                 ap_rputs("</td></tr>\n", r);
 686
 687                 ++worker;
 688             }
 689             ap_rputs("</table>\n", r);
 690             ++balancer;
 691         }
 692         ap_rputs("<hr />\n", r);
 693         if (wsel && bsel) {
 694             ap_rputs("<h3>Edit worker settings for ", r);
 695             ap_rvputs(r, wsel->w->name, "</h3>\n", NULL);
 696             ap_rvputs(r, "<form method=\"GET\" action=\"", NULL);
 697             ap_rvputs(r, r->uri, "\">\n<dl>", NULL);
 698             ap_rputs("<table><tr><td>Load factor:</td><td><input name=\"lf\" type=text ", r);
 699             ap_rprintf(r, "value=\"%.2f\"></td><tr>\n", wsel->s->lbfactor);
 700             ap_rputs("<tr><td>Route:</td><td><input name=\"wr\" type=text ", r);
 701             ap_rvputs(r, "value=\"", wsel->w->route, NULL);
 702             ap_rputs("\"></td><tr>\n", r);
 703             ap_rputs("<tr><td>Route Redirect:</td><td><input name=\"rr\" type=text ", r);
 704             ap_rvputs(r, "value=\"", wsel->w->redirect, NULL);
 705             ap_rputs("\"></td><tr>\n", r);
 706             ap_rputs("<tr><td>Disabled:</td><td><input name=\"dw\" type=checkbox", r);
 707             if (wsel->w->status & PROXY_WORKER_DISABLED)
 708                 ap_rputs(" checked", r);
 709             ap_rputs("></td><tr>\n", r);
 710             ap_rputs("<tr><td colspan=2><input type=submit value=\"Submit\"></td></tr>\n", r);
 711             ap_rvputs(r, "</table>\n<input type=hidden name=\"s\" ", NULL);
 712             ap_rvputs(r, "value=\"", wsel->w->scheme, "\">\n", NULL);
 713             ap_rvputs(r, "<input type=hidden name=\"w\" ", NULL);
 714             ap_rvputs(r, "value=\"", wsel->w->hostname, "\">\n", NULL);
 715             ap_rvputs(r, "<input type=hidden name=\"b\" ", NULL);
 716             ap_rvputs(r, "value=\"", bsel->name + sizeof("balancer://") - 1,
 717                       "\">\n</form>\n", NULL);
 718             ap_rputs("<hr />\n", r);
 719         }
 720         else if (bsel) {
 721             ap_rputs("<h3>Edit balancer settings for ", r);
 722             ap_rvputs(r, bsel->name, "</h3>\n", NULL);
 723             ap_rvputs(r, "<form method=\"GET\" action=\"", NULL);
 724             ap_rvputs(r, r->uri, "\">\n<dl>", NULL);
 725             ap_rputs("<table><tr><td>StickySession Identifier:</td><td><input name=\"ss\" type=text ", r);
 726             if (bsel->sticky)
 727                 ap_rvputs(r, "value=\"", bsel->sticky, "\"", NULL);
 728             ap_rputs("></td><tr>\n<tr><td>Timeout:</td><td><input name=\"tm\" type=text ", r);
 729             ap_rprintf(r, "value=\"%" APR_TIME_T_FMT "\"></td></tr>\n",
 730                        apr_time_sec(bsel->timeout));
 731             ap_rputs("<tr><td colspan=2><input type=submit value=\"Submit\"></td></tr>\n", r);
 732             ap_rvputs(r, "</table>\n<input type=hidden name=\"b\" ", NULL);
 733             ap_rvputs(r, "value=\"", bsel->name + sizeof("balancer://") - 1,
 734                       "\">\n</form>\n", NULL);
 735             ap_rputs("<hr />\n", r);
 736         }
 737         ap_rputs(ap_psignature("",r), r);
 738         ap_rputs("</body></html>\n", r);
 739     }
 740     return OK;
 741 }
 742
 743 static void ap_proxy_balancer_register_hook(apr_pool_t *p)
 744 {
 745     /* manager handler */
 746     ap_hook_handler(balancer_handler, NULL, NULL, APR_HOOK_FIRST);
 747     proxy_hook_pre_request(proxy_balancer_pre_request, NULL, NULL, APR_HOOK_FIRST);
 748     proxy_hook_post_request(proxy_balancer_post_request, NULL, NULL, APR_HOOK_FIRST);
 749 }
 750
 751 module AP_MODULE_DECLARE_DATA proxy_balancer_module = {
 752     STANDARD20_MODULE_STUFF,
 753     NULL,       /* create per-directory config structure */
 754     NULL,       /* merge per-directory config structures */
 755     NULL,       /* create per-server config structure */
 756     NULL,       /* merge per-server config structures */
 757     NULL,       /* command apr_table_t */
 758     ap_proxy_balancer_register_hook /* register hooks */
 759 };