diff options
Diffstat (limited to 'modules/proxy/balancers/mod_lbmethod_bytraffic.c')
| -rw-r--r-- | modules/proxy/balancers/mod_lbmethod_bytraffic.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/modules/proxy/balancers/mod_lbmethod_bytraffic.c b/modules/proxy/balancers/mod_lbmethod_bytraffic.c new file mode 100644 index 0000000..6cfab94 --- /dev/null +++ b/modules/proxy/balancers/mod_lbmethod_bytraffic.c @@ -0,0 +1,135 @@ +/* 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_bytraffic_module; + +static APR_OPTIONAL_FN_TYPE(proxy_balancer_get_best_worker) + *ap_proxy_balancer_get_best_worker_fn = NULL; + +static int is_best_bytraffic(proxy_worker *current, proxy_worker *prev_best, void *baton) +{ + apr_off_t *min_traffic = (apr_off_t *)baton; + apr_off_t traffic = (current->s->transferred / current->s->lbfactor) + + (current->s->read / current->s->lbfactor); + + if (!prev_best || (traffic < *min_traffic)) { + *min_traffic = traffic; + + return TRUE; + } + + return FALSE; +} + +/* + * 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) +{ + apr_off_t min_traffic = 0; + + return ap_proxy_balancer_get_best_worker_fn(balancer, r, is_best_bytraffic, + &min_traffic); +} + +/* 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; + (*worker)->s->transferred = 0; + (*worker)->s->read = 0; + } + return APR_SUCCESS; +} + +static apr_status_t age(proxy_balancer *balancer, server_rec *s) +{ + return APR_SUCCESS; +} + +static const proxy_balancer_method bytraffic = +{ + "bytraffic", + &find_best_bytraffic, + NULL, + &reset, + &age, + NULL +}; + +/* post_config hook: */ +static int lbmethod_bytraffic_post_config(apr_pool_t *pconf, apr_pool_t *plog, + apr_pool_t *ptemp, server_rec *s) +{ + + /* lbmethod_bytraffic_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(10150) + "mod_proxy must be loaded for mod_lbmethod_bytraffic"); + return !OK; + } + + return OK; +} + +static void register_hook(apr_pool_t *p) +{ + ap_register_provider(p, PROXY_LBMETHOD, "bytraffic", "0", &bytraffic); + ap_hook_post_config(lbmethod_bytraffic_post_config, NULL, NULL, APR_HOOK_MIDDLE); +} + +AP_DECLARE_MODULE(lbmethod_bytraffic) = { + 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 */ +}; |