| /* Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "mod_proxy.h" |
| #include "scoreboard.h" |
| #include "ap_mpm.h" |
| #include "apr_version.h" |
| #include "ap_hooks.h" |
| |
| module AP_MODULE_DECLARE_DATA lbmethod_bybusyness_module; |
| |
| static APR_OPTIONAL_FN_TYPE(proxy_balancer_get_best_worker) |
| *ap_proxy_balancer_get_best_worker_fn = NULL; |
| |
| static int is_best_bybusyness(proxy_worker *current, proxy_worker *prev_best, void *baton) |
| { |
| int *total_factor = (int *)baton; |
| |
| current->s->lbstatus += current->s->lbfactor; |
| *total_factor += current->s->lbfactor; |
| |
| return ( |
| !prev_best |
| || (current->s->busy < prev_best->s->busy) |
| || ( |
| (current->s->busy == prev_best->s->busy) |
| && (current->s->lbstatus > prev_best->s->lbstatus) |
| ) |
| ); |
| } |
| |
| static proxy_worker *find_best_bybusyness(proxy_balancer *balancer, |
| request_rec *r) |
| { |
| int total_factor = 0; |
| proxy_worker *worker = |
| ap_proxy_balancer_get_best_worker_fn(balancer, r, is_best_bybusyness, |
| &total_factor); |
| |
| if (worker) { |
| worker->s->lbstatus -= total_factor; |
| } |
| |
| return worker; |
| } |
| |
| /* assumed to be mutex protected by caller */ |
| static apr_status_t reset(proxy_balancer *balancer, server_rec *s) |
| { |
| int i; |
| proxy_worker **worker; |
| worker = (proxy_worker **)balancer->workers->elts; |
| for (i = 0; i < balancer->workers->nelts; i++, worker++) { |
| (*worker)->s->lbstatus = 0; |
| (*worker)->s->busy = 0; |
| } |
| return APR_SUCCESS; |
| } |
| |
| static apr_status_t age(proxy_balancer *balancer, server_rec *s) |
| { |
| return APR_SUCCESS; |
| } |
| |
| static const proxy_balancer_method bybusyness = |
| { |
| "bybusyness", |
| &find_best_bybusyness, |
| NULL, |
| &reset, |
| &age, |
| NULL |
| }; |
| |
| /* post_config hook: */ |
| static int lbmethod_bybusyness_post_config(apr_pool_t *pconf, apr_pool_t *plog, |
| apr_pool_t *ptemp, server_rec *s) |
| { |
| |
| /* lbmethod_bybusyness_post_config() will be called twice during startup. So, don't |
| * set up the static data the 1st time through. */ |
| if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG) { |
| return OK; |
| } |
| |
| ap_proxy_balancer_get_best_worker_fn = |
| APR_RETRIEVE_OPTIONAL_FN(proxy_balancer_get_best_worker); |
| if (!ap_proxy_balancer_get_best_worker_fn) { |
| ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(10151) |
| "mod_proxy must be loaded for mod_lbmethod_bybusyness"); |
| return !OK; |
| } |
| |
| return OK; |
| } |
| |
| static void register_hook(apr_pool_t *p) |
| { |
| ap_register_provider(p, PROXY_LBMETHOD, "bybusyness", "0", &bybusyness); |
| ap_hook_post_config(lbmethod_bybusyness_post_config, NULL, NULL, APR_HOOK_MIDDLE); |
| } |
| |
| AP_DECLARE_MODULE(lbmethod_bybusyness) = { |
| STANDARD20_MODULE_STUFF, |
| NULL, /* create per-directory config structure */ |
| NULL, /* merge per-directory config structures */ |
| NULL, /* create per-server config structure */ |
| NULL, /* merge per-server config structures */ |
| NULL, /* command apr_table_t */ |
| register_hook /* register hooks */ |
| }; |