From 7945337ff0a160bbd30e28073484540bbea23c8e Mon Sep 17 00:00:00 2001 From: Jim Jagielski Date: Wed, 3 Dec 2008 16:07:11 +0000 Subject: [PATCH] Add in independent bytraffic lbmethod git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@722950 13f79535-47bb-0310-9956-ffa450edef68 --- .../proxy/balancers/mod_lbmethod_bytraffic.c | 132 ++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 modules/proxy/balancers/mod_lbmethod_bytraffic.c diff --git a/modules/proxy/balancers/mod_lbmethod_bytraffic.c b/modules/proxy/balancers/mod_lbmethod_bytraffic.c new file mode 100644 index 0000000000..59a687b321 --- /dev/null +++ b/modules/proxy/balancers/mod_lbmethod_bytraffic.c @@ -0,0 +1,132 @@ +/* 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 "apr_hooks.h" + +module AP_MODULE_DECLARE_DATA lbmethod_bytraffic_module; + +/* + * 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 *mycandidate = NULL; + int cur_lbset = 0; + int max_lbset = 0; + int checking_standby; + int checked_standby; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, + "proxy: Entering bytraffic for BALANCER (%s)", + balancer->name); + + /* First try to see if we have available candidate */ + do { + checking_standby = checked_standby = 0; + while (!mycandidate && !checked_standby) { + worker = (proxy_worker *)balancer->workers->elts; + for (i = 0; i < balancer->workers->nelts; i++, worker++) { + if (!checking_standby) { /* first time through */ + if (worker->s->lbset > max_lbset) + max_lbset = worker->s->lbset; + } + if (worker->s->lbset > cur_lbset) + continue; + if ( (checking_standby ? !PROXY_WORKER_IS_STANDBY(worker) : PROXY_WORKER_IS_STANDBY(worker)) ) + continue; + /* 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 (!mycandidate || mytraffic < curmin) { + mycandidate = worker; + curmin = mytraffic; + } + } + } + checked_standby = checking_standby++; + } + cur_lbset++; + } while (cur_lbset <= max_lbset && !mycandidate); + + if (mycandidate) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, + "proxy: bytraffic selected worker \"%s\" : busy %" APR_SIZE_T_FMT, + mycandidate->name, mycandidate->s->busy); + + } + + return mycandidate; +} + +static const proxy_balancer_method bytraffic = +{ + "bytraffic", + &find_best_bytraffic, + NULL +}; + +static void register_hook(apr_pool_t *p) +{ + /* Only the mpm_winnt has child init hook handler. + * make sure that we are called after the mpm + * initializes and after the mod_proxy + */ + ap_register_provider(p, PROXY_LBMETHOD, "bytraffic", "0", &bytraffic); +} + +module AP_MODULE_DECLARE_DATA lbmethod_bytraffic_module = { + 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 */ +}; -- 2.40.0