mod_proxy_balancer.c revision c64fb33e0c4634fd352c4a6c143cd1a087c09b13
181e56d8b348d301d615ccf5465ae600fee2867berikabele/* Licensed to the Apache Software Foundation (ASF) under one or more
181e56d8b348d301d615ccf5465ae600fee2867berikabele * contributor license agreements. See the NOTICE file distributed with
fd9abdda70912b99b24e3bf1a38f26fde908a74cnd * this work for additional information regarding copyright ownership.
fd9abdda70912b99b24e3bf1a38f26fde908a74cnd * The ASF licenses this file to You under the Apache License, Version 2.0
fd9abdda70912b99b24e3bf1a38f26fde908a74cnd * (the "License"); you may not use this file except in compliance with
e4e4d8f25022f178ceb567b9f2b37be34b729f08slive * the License. You may obtain a copy of the License at
e4e4d8f25022f178ceb567b9f2b37be34b729f08slive *
e4e4d8f25022f178ceb567b9f2b37be34b729f08slive * http://www.apache.org/licenses/LICENSE-2.0
5a58787efeb02a1c3f06569d019ad81fd2efa06end *
96ad5d81ee4a2cc66a4ae19893efc8aa6d06fae7jailletc * Unless required by applicable law or agreed to in writing, software
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim * distributed under the License is distributed on an "AS IS" BASIS,
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen * See the License for the specific language governing permissions and
2e545ce2450a9953665f701bb05350f0d3f26275nd * limitations under the License.
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen */
d29d9ab4614ff992b0e8de6e2b88d52b6f1f153erbowen
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim/* Load balancer module for Apache proxy */
5a58787efeb02a1c3f06569d019ad81fd2efa06end
af33a4994ae2ff15bc67d19ff1a7feb906745bf8rbowen#define CORE_PRIVATE
3f08db06526d6901aa08c110b5bc7dde6bc39905nd
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim#include "mod_proxy.h"
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim#include "ap_mpm.h"
5a58787efeb02a1c3f06569d019ad81fd2efa06end#include "apr_version.h"
3f08db06526d6901aa08c110b5bc7dde6bc39905nd#include "apr_hooks.h"
3b3b7fc78d1f5bfc2769903375050048ff41ff26nd
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim#if APR_HAVE_UNISTD_H
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim#include <unistd.h> /* for getpid() */
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim#endif
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim
7f5b59ccc63c0c0e3e678a168f09ee6a2f51f9d0ndmodule AP_MODULE_DECLARE_DATA proxy_balancer_module;
fac8c35bfb158112226ab43ddf84d59daca5dc30nd
f086b4b402fa9a2fefc7dda85de2a3cc1cd0a654rjungstatic int proxy_balancer_canon(request_rec *r, char *url)
3b3b7fc78d1f5bfc2769903375050048ff41ff26nd{
3b3b7fc78d1f5bfc2769903375050048ff41ff26nd char *host, *path, *search;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen const char *err;
193ba167383a0599478b84ea51ac9ddec2bc0328rbowen apr_port_t port = 0;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
193ba167383a0599478b84ea51ac9ddec2bc0328rbowen if (strncasecmp(url, "balancer:", 9) == 0) {
eb0e379101aca2125fcc0bd316078492d39840bdcovener url += 9;
eb0e379101aca2125fcc0bd316078492d39840bdcovener }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen else {
e4ca72aa494fed7b6948012734b9c9c098fbba07nd return DECLINED;
e4ca72aa494fed7b6948012734b9c9c098fbba07nd }
36a1dcd0eb7ff5a01f23c95d58bf863da1c7045bkess
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
51db0c8d97d68b94230ba4972c7a62b55314acd3slive "proxy: BALANCER: canonicalising URL %s", url);
21d8860f1cac3103fabffb8f718769126f118c52rbowen
51db0c8d97d68b94230ba4972c7a62b55314acd3slive /* do syntatic check.
5a58787efeb02a1c3f06569d019ad81fd2efa06end * We break the URL into host, port, path, search
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim */
5a58787efeb02a1c3f06569d019ad81fd2efa06end err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port);
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim if (err) {
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim "error parsing URL %s: %s",
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim url, err);
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim return HTTP_BAD_REQUEST;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim }
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim /* now parse path/search args, according to rfc1738 */
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim /* N.B. if this isn't a true proxy request, then the URL _path_
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim * has already been decoded. True proxy requests have r->uri
0fd8d4360a2d123a9db5bad1b505b6be405abbd4igalic * == r->unparsed_uri, and no others have that property.
30471a4650391f57975f60bbb6e4a90be7b284bfhumbedooh */
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim if (r->uri == r->unparsed_uri) {
5a58787efeb02a1c3f06569d019ad81fd2efa06end search = strchr(url, '?');
5a58787efeb02a1c3f06569d019ad81fd2efa06end if (search != NULL)
e4e4d8f25022f178ceb567b9f2b37be34b729f08slive *(search++) = '\0';
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen else
9fc1345bb54ea7f68c2e59ff3a618c1237a30918yoshiki search = r->args;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /* process path */
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen path = ap_proxy_canonenc(r->pool, url, strlen(url), enc_path, 0, r->proxyreq);
7310251f839057f76c21e4b794b74af31fe3a3daslive if (path == NULL)
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen return HTTP_BAD_REQUEST;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen r->filename = apr_pstrcat(r->pool, "proxy:balancer://", host,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen "/", path, (search) ? "?" : "", (search) ? search : "", NULL);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen r->path_info = apr_pstrcat(r->pool, "/", path, NULL);
e4ca72aa494fed7b6948012734b9c9c098fbba07nd
55b585a80949b1740ebf8d94ad154b2a4c3a8a81nd return OK;
55b585a80949b1740ebf8d94ad154b2a4c3a8a81nd}
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowenstatic int init_balancer_members(proxy_server_conf *conf, server_rec *s,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen proxy_balancer *balancer)
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen{
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen int i;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen proxy_worker *workers;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen workers = (proxy_worker *)balancer->workers->elts;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen for (i = 0; i < balancer->workers->nelts; i++) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen ap_proxy_initialize_worker_share(conf, workers, s);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen ap_proxy_initialize_worker(workers, s);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen ++workers;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen workers = (proxy_worker *)balancer->workers->elts;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen for (i = 0; i < balancer->workers->nelts; i++) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /* Set to the original configuration */
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen workers[i].s->lbstatus = workers[i].s->lbfactor =
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen (workers[i].lbfactor ? workers[i].lbfactor : 1);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen workers[i].s->lbset = workers[i].lbset;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /* Set default number of attempts to the number of
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * workers.
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen */
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if (!balancer->max_attempts_set && balancer->workers->nelts > 1) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen balancer->max_attempts = balancer->workers->nelts - 1;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen balancer->max_attempts_set = 1;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen return 0;
e4ca72aa494fed7b6948012734b9c9c098fbba07nd}
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen/* Retrieve the parameter with the given name
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * Something like 'JSESSIONID=12345...N'
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen */
e4ca72aa494fed7b6948012734b9c9c098fbba07ndstatic char *get_path_param(apr_pool_t *pool, char *url,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen const char *name)
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen{
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen char *path = NULL;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen for (path = strstr(url, name); path; path = strstr(path + 1, name)) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen path += strlen(name);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if (*path == '=') {
e4ca72aa494fed7b6948012734b9c9c098fbba07nd /*
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim * Session path was found, get it's value
5a58787efeb02a1c3f06569d019ad81fd2efa06end */
5a58787efeb02a1c3f06569d019ad81fd2efa06end ++path;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if (strlen(path)) {
193ba167383a0599478b84ea51ac9ddec2bc0328rbowen char *q;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen path = apr_strtok(apr_pstrdup(pool, path), "?&", &q);
f915b3725d6bce16d5fa02403601fb9e6872cf49kess return path;
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen }
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen }
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen }
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen return NULL;
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen}
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen
7859c11126b92a9ff7ca9ebf9ec0c7dee8ddb70fcovenerstatic char *get_cookie_param(request_rec *r, const char *name)
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen{
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen const char *cookies;
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar const char *start_cookie;
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen if ((cookies = apr_table_get(r->headers_in, "Cookie"))) {
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen for (start_cookie = ap_strstr_c(cookies, name); start_cookie;
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen start_cookie = ap_strstr_c(start_cookie + 1, name)) {
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar if (start_cookie == cookies ||
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar start_cookie[-1] == ';' ||
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen start_cookie[-1] == ',' ||
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen isspace(start_cookie[-1])) {
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar start_cookie += strlen(name);
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar while(*start_cookie && isspace(*start_cookie))
203a32ea2557b7e1abd50c6bb1ce3bb69cd1570frbowen ++start_cookie;
a99c5d4cc3cab6a62b04d52000dbc22ce1fa2d94coar if (*start_cookie == '=' && start_cookie[1]) {
f915b3725d6bce16d5fa02403601fb9e6872cf49kess /*
f915b3725d6bce16d5fa02403601fb9e6872cf49kess * Session cookie was found, get it's value
193ba167383a0599478b84ea51ac9ddec2bc0328rbowen */
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen char *end_cookie, *cookie;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen ++start_cookie;
36461702119f178a2a47ca2fe3766a417e282402rbowen cookie = apr_pstrdup(r->pool, start_cookie);
36461702119f178a2a47ca2fe3766a417e282402rbowen if ((end_cookie = strchr(cookie, ';')) != NULL)
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen *end_cookie = '\0';
f915b3725d6bce16d5fa02403601fb9e6872cf49kess if((end_cookie = strchr(cookie, ',')) != NULL)
316f02e3836836c82e19019ff23f90a7ebc65289nilgun *end_cookie = '\0';
e4e4d8f25022f178ceb567b9f2b37be34b729f08slive return cookie;
c4563a40efeec2adf1ef024a8af1a2bea9bc7adfpquerna }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
f915b3725d6bce16d5fa02403601fb9e6872cf49kess }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen return NULL;
f915b3725d6bce16d5fa02403601fb9e6872cf49kess}
f915b3725d6bce16d5fa02403601fb9e6872cf49kess
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen/* Find the worker that has the 'route' defined
36a1dcd0eb7ff5a01f23c95d58bf863da1c7045bkess */
f915b3725d6bce16d5fa02403601fb9e6872cf49kessstatic proxy_worker *find_route_worker(proxy_balancer *balancer,
f915b3725d6bce16d5fa02403601fb9e6872cf49kess const char *route, request_rec *r)
e4ca72aa494fed7b6948012734b9c9c098fbba07nd{
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen int i;
f915b3725d6bce16d5fa02403601fb9e6872cf49kess int checking_standby;
f915b3725d6bce16d5fa02403601fb9e6872cf49kess int checked_standby;
f915b3725d6bce16d5fa02403601fb9e6872cf49kess
f915b3725d6bce16d5fa02403601fb9e6872cf49kess proxy_worker *worker;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen checking_standby = checked_standby = 0;
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf while (!checked_standby) {
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf worker = (proxy_worker *)balancer->workers->elts;
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf for (i = 0; i < balancer->workers->nelts; i++, worker++) {
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf if ( (checking_standby ? !PROXY_WORKER_IS_STANDBY(worker) : PROXY_WORKER_IS_STANDBY(worker)) )
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim continue;
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf if (*(worker->s->route) && strcmp(worker->s->route, route) == 0) {
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf if (worker && PROXY_WORKER_IS_USABLE(worker)) {
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf return worker;
e4ca72aa494fed7b6948012734b9c9c098fbba07nd } else {
f915b3725d6bce16d5fa02403601fb9e6872cf49kess /*
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim * If the worker is in error state run
5a58787efeb02a1c3f06569d019ad81fd2efa06end * retry on that worker. It will be marked as
5a58787efeb02a1c3f06569d019ad81fd2efa06end * operational if the retry timeout is elapsed.
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * The worker might still be unusable, but we try
e4ca72aa494fed7b6948012734b9c9c098fbba07nd * anyway.
e4ca72aa494fed7b6948012734b9c9c098fbba07nd */
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive ap_proxy_retry_worker("BALANCER", worker, r->server);
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive if (PROXY_WORKER_IS_USABLE(worker)) {
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive return worker;
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive } else {
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive /*
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * We have a worker that is unusable.
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * It can be in error or disabled, but in case
645a5920d9fdd53a7f75a6a16e87ff27781b0133slive * it has a redirection set use that redirection worker.
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * This enables to safely remove the member from the
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * balancer. Of course you will need some kind of
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * session replication between those two remote.
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive */
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive if (*worker->s->redirect) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen proxy_worker *rworker = NULL;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim rworker = find_route_worker(balancer, worker->s->redirect, r);
5a58787efeb02a1c3f06569d019ad81fd2efa06end /* Check if the redirect worker is usable */
5a58787efeb02a1c3f06569d019ad81fd2efa06end if (rworker && !PROXY_WORKER_IS_USABLE(rworker)) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /*
654d8eb036bedc99e90e11910ee02d3421417697rbowen * If the worker is in error state run
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * retry on that worker. It will be marked as
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * operational if the retry timeout is elapsed.
181e56d8b348d301d615ccf5465ae600fee2867berikabele * The worker might still be unusable, but we try
e4ca72aa494fed7b6948012734b9c9c098fbba07nd * anyway.
e4ca72aa494fed7b6948012734b9c9c098fbba07nd */
181e56d8b348d301d615ccf5465ae600fee2867berikabele ap_proxy_retry_worker("BALANCER", rworker, r->server);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if (rworker && PROXY_WORKER_IS_USABLE(rworker))
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen return rworker;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim }
5a58787efeb02a1c3f06569d019ad81fd2efa06end }
5a58787efeb02a1c3f06569d019ad81fd2efa06end }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen checked_standby = checking_standby++;
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive }
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive return NULL;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim}
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive
e4ca72aa494fed7b6948012734b9c9c098fbba07ndstatic proxy_worker *find_session_route(proxy_balancer *balancer,
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive request_rec *r,
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive char **route,
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive const char **sticky_used,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen char **url)
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen{
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen proxy_worker *worker = NULL;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive if (!balancer->sticky)
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive return NULL;
645a5920d9fdd53a7f75a6a16e87ff27781b0133slive /* Try to find the sticky route inside url */
645a5920d9fdd53a7f75a6a16e87ff27781b0133slive *route = get_path_param(r->pool, *url, balancer->sticky_path);
645a5920d9fdd53a7f75a6a16e87ff27781b0133slive if (*route) {
645a5920d9fdd53a7f75a6a16e87ff27781b0133slive ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive "proxy: BALANCER: Found value %s for "
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive "stickysession %s", *route, balancer->sticky_path);
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive *sticky_used = balancer->sticky_path;
c7ed811e89712261aaa4432198e331389044e1f8rjung }
c7ed811e89712261aaa4432198e331389044e1f8rjung else {
c7ed811e89712261aaa4432198e331389044e1f8rjung *route = get_cookie_param(r, balancer->sticky);
c7ed811e89712261aaa4432198e331389044e1f8rjung if (*route) {
c7ed811e89712261aaa4432198e331389044e1f8rjung *sticky_used = balancer->sticky;
c7ed811e89712261aaa4432198e331389044e1f8rjung ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
c7ed811e89712261aaa4432198e331389044e1f8rjung "proxy: BALANCER: Found value %s for "
c7ed811e89712261aaa4432198e331389044e1f8rjung "stickysession %s", *route, balancer->sticky);
475381aeef8ae4f7986e7b02a8d480777d5a14b7nd }
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive }
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive /*
c7ed811e89712261aaa4432198e331389044e1f8rjung * If we found a value for sticksession, find the first '.' within.
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * Everything after '.' (if present) is our route.
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim */
f87c874dc2012c5e410ea0d25ffda6a61c6c2917slive if ((*route) && ((*route = strchr(*route, '.')) != NULL ))
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive (*route)++;
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive if ((*route) && (**route)) {
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim "proxy: BALANCER: Found route %s", *route);
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive /* We have a route in path or in cookie
9ed703ab1543b3300f4b60c0405fc1a212b601c8slive * Find the worker that has this route defined.
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim */
41180d477c0228e5c09e2ad1393054b602295eecrbowen worker = find_route_worker(balancer, *route, r);
41180d477c0228e5c09e2ad1393054b602295eecrbowen if (worker && strcmp(*route, worker->s->route)) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /*
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * Notice that the route of the worker chosen is different from
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * the route supplied by the client.
36a1dcd0eb7ff5a01f23c95d58bf863da1c7045bkess */
c7ed811e89712261aaa4432198e331389044e1f8rjung apr_table_setn(r->subprocess_env, "BALANCER_ROUTE_CHANGED", "1");
c7ed811e89712261aaa4432198e331389044e1f8rjung ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen "proxy: BALANCER: Route changed from %s to %s",
181e56d8b348d301d615ccf5465ae600fee2867berikabele *route, worker->s->route);
181e56d8b348d301d615ccf5465ae600fee2867berikabele }
181e56d8b348d301d615ccf5465ae600fee2867berikabele return worker;
c7ed811e89712261aaa4432198e331389044e1f8rjung }
c7ed811e89712261aaa4432198e331389044e1f8rjung else
181e56d8b348d301d615ccf5465ae600fee2867berikabele return NULL;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen}
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim
36a1dcd0eb7ff5a01f23c95d58bf863da1c7045bkessstatic proxy_worker *find_best_worker(proxy_balancer *balancer,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen request_rec *r)
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen{
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim proxy_worker *candidate = NULL;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim apr_status_t rv;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim
5a58787efeb02a1c3f06569d019ad81fd2efa06end if ((rv = PROXY_THREAD_LOCK(balancer)) != APR_SUCCESS) {
5a58787efeb02a1c3f06569d019ad81fd2efa06end ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen "proxy: BALANCER: (%s). Lock failed for find_best_worker()", balancer->name);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen return NULL;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
181e56d8b348d301d615ccf5465ae600fee2867berikabele candidate = (*balancer->lbmethod->finder)(balancer, r);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if (candidate)
e4ca72aa494fed7b6948012734b9c9c098fbba07nd candidate->s->elected++;
e4ca72aa494fed7b6948012734b9c9c098fbba07nd
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf/*
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim PROXY_THREAD_UNLOCK(balancer);
5a58787efeb02a1c3f06569d019ad81fd2efa06end return NULL;
5a58787efeb02a1c3f06569d019ad81fd2efa06end*/
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen
51db0c8d97d68b94230ba4972c7a62b55314acd3slive if ((rv = PROXY_THREAD_UNLOCK(balancer)) != APR_SUCCESS) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen "proxy: BALANCER: (%s). Unlock failed for find_best_worker()", balancer->name);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
181e56d8b348d301d615ccf5465ae600fee2867berikabele
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if (candidate == NULL) {
847155534c9678f68502de3809d8d6d2623ac32erbowen /* All the workers are in error state or disabled.
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen * If the balancer has a timeout sleep for a while
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen * and try again to find the worker. The chances are
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen * that some other thread will release a connection.
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * By default the timeout is not set, and the server
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * returns SERVER_BUSY.
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim */
5a58787efeb02a1c3f06569d019ad81fd2efa06end#if APR_HAS_THREADS
5a58787efeb02a1c3f06569d019ad81fd2efa06end if (balancer->timeout) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /* XXX: This can perhaps be build using some
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * smarter mechanism, like tread_cond.
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen * But since the statuses can came from
738504ae90e2233e22f4fd0da1d8ccf0b96e579end * different childs, use the provided algo.
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen */
181e56d8b348d301d615ccf5465ae600fee2867berikabele apr_interval_time_t timeout = balancer->timeout;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen apr_interval_time_t step, tval = 0;
9a58dc6a2b26ec128b1270cf48810e705f1a90dbsf /* Set the timeout to 0 so that we don't
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen * end in infinite loop
6df89e6e4adeb986b41b7ec6b7593a887e031ce7nd */
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim balancer->timeout = 0;
5a58787efeb02a1c3f06569d019ad81fd2efa06end step = timeout / 100;
5a58787efeb02a1c3f06569d019ad81fd2efa06end while (tval < timeout) {
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen apr_sleep(step);
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen /* Try again */
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen if ((candidate = find_best_worker(balancer, r)))
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen break;
e4ca72aa494fed7b6948012734b9c9c098fbba07nd tval += step;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen /* restore the timeout */
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen balancer->timeout = timeout;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen#endif
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen }
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen return candidate;
57d0156f7bbd9ea3a72342cf9912aba61d118702rbowen}
e4ca72aa494fed7b6948012734b9c9c098fbba07nd
7add1372edb1ee95a2c4d1314df4c7567bda7c62jimstatic int rewrite_url(request_rec *r, proxy_worker *worker,
51db0c8d97d68b94230ba4972c7a62b55314acd3slive char **url)
51db0c8d97d68b94230ba4972c7a62b55314acd3slive{
51db0c8d97d68b94230ba4972c7a62b55314acd3slive const char *scheme = strstr(*url, "://");
51db0c8d97d68b94230ba4972c7a62b55314acd3slive const char *path = NULL;
51db0c8d97d68b94230ba4972c7a62b55314acd3slive
51db0c8d97d68b94230ba4972c7a62b55314acd3slive if (scheme)
c33e58aa23ba620d1caab0558791ad164e819930humbedooh path = ap_strchr_c(scheme + 3, '/');
51db0c8d97d68b94230ba4972c7a62b55314acd3slive
51db0c8d97d68b94230ba4972c7a62b55314acd3slive /* we break the URL into host, port, uri */
157312a2bcbad225c12462fc6d74b1aa3f32dceehumbedooh if (!worker) {
51db0c8d97d68b94230ba4972c7a62b55314acd3slive return ap_proxyerror(r, HTTP_BAD_REQUEST, apr_pstrcat(r->pool,
51db0c8d97d68b94230ba4972c7a62b55314acd3slive "missing worker. URI cannot be parsed: ", *url,
51db0c8d97d68b94230ba4972c7a62b55314acd3slive NULL));
e4ca72aa494fed7b6948012734b9c9c098fbba07nd }
51db0c8d97d68b94230ba4972c7a62b55314acd3slive
51db0c8d97d68b94230ba4972c7a62b55314acd3slive *url = apr_pstrcat(r->pool, worker->name, path, NULL);
51db0c8d97d68b94230ba4972c7a62b55314acd3slive
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim return OK;
51db0c8d97d68b94230ba4972c7a62b55314acd3slive}
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim
51db0c8d97d68b94230ba4972c7a62b55314acd3slivestatic void force_recovery(proxy_balancer *balancer, server_rec *s)
e4ca72aa494fed7b6948012734b9c9c098fbba07nd{
51db0c8d97d68b94230ba4972c7a62b55314acd3slive int i;
6771d932c350b8af84039f3c71ebf9313dd52569kess int ok = 0;
6771d932c350b8af84039f3c71ebf9313dd52569kess proxy_worker *worker;
6771d932c350b8af84039f3c71ebf9313dd52569kess
6771d932c350b8af84039f3c71ebf9313dd52569kess worker = (proxy_worker *)balancer->workers->elts;
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim for (i = 0; i < balancer->workers->nelts; i++, worker++) {
6771d932c350b8af84039f3c71ebf9313dd52569kess if (!(worker->s->status & PROXY_WORKER_IN_ERROR)) {
6771d932c350b8af84039f3c71ebf9313dd52569kess ok = 1;
6771d932c350b8af84039f3c71ebf9313dd52569kess break;
6771d932c350b8af84039f3c71ebf9313dd52569kess }
51db0c8d97d68b94230ba4972c7a62b55314acd3slive }
51db0c8d97d68b94230ba4972c7a62b55314acd3slive if (!ok) {
51db0c8d97d68b94230ba4972c7a62b55314acd3slive /* If all workers are in error state force the recovery.
51db0c8d97d68b94230ba4972c7a62b55314acd3slive */
51db0c8d97d68b94230ba4972c7a62b55314acd3slive worker = (proxy_worker *)balancer->workers->elts;
e4ca72aa494fed7b6948012734b9c9c098fbba07nd for (i = 0; i < balancer->workers->nelts; i++, worker++) {
e4ca72aa494fed7b6948012734b9c9c098fbba07nd ++worker->s->retries;
51db0c8d97d68b94230ba4972c7a62b55314acd3slive worker->s->status &= ~PROXY_WORKER_IN_ERROR;
51db0c8d97d68b94230ba4972c7a62b55314acd3slive ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
51db0c8d97d68b94230ba4972c7a62b55314acd3slive "proxy: BALANCER: (%s). Forcing recovery for worker (%s)",
51db0c8d97d68b94230ba4972c7a62b55314acd3slive balancer->name, worker->hostname);
51db0c8d97d68b94230ba4972c7a62b55314acd3slive }
51db0c8d97d68b94230ba4972c7a62b55314acd3slive }
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim}
51db0c8d97d68b94230ba4972c7a62b55314acd3slive
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowenstatic int proxy_balancer_pre_request(proxy_worker **worker,
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen proxy_balancer **balancer,
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim request_rec *r,
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen proxy_server_conf *conf, char **url)
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen{
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen int access_status;
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen proxy_worker *runtime;
5e7452e356ccbbc11d7a19368f40ae54a1d6c3d3rbowen char *route = NULL;
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen const char *sticky = NULL;
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen apr_status_t rv;
0fd8d4360a2d123a9db5bad1b505b6be405abbd4igalic
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen *worker = NULL;
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen /* Step 1: check if the url is for us
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen * The url we can handle starts with 'balancer://'
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen * If balancer is already provided skip the search
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen * for balancer, because this is failover attempt.
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen */
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen if (!*balancer &&
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen !(*balancer = ap_proxy_get_balancer(r->pool, conf, *url)))
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen return DECLINED;
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen /* Step 2: Lock the LoadBalancer
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen * XXX: perhaps we need the process lock here
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen */
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen if ((rv = PROXY_THREAD_LOCK(*balancer)) != APR_SUCCESS) {
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen "proxy: BALANCER: (%s). Lock failed for pre_request",
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen (*balancer)->name);
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen return DECLINED;
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen }
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen
c6063a3218284e4373e5e6436f420aa10fa5b7dbrbowen /* Step 3: force recovery */
5a58787efeb02a1c3f06569d019ad81fd2efa06end force_recovery(*balancer, r->server);
3b3b7fc78d1f5bfc2769903375050048ff41ff26nd
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim /* Step 4: find the session route */
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim runtime = find_session_route(*balancer, r, &route, &sticky, url);
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim if (runtime) {
7add1372edb1ee95a2c4d1314df4c7567bda7c62jim int i, total_factor = 0;
7f5b59ccc63c0c0e3e678a168f09ee6a2f51f9d0nd proxy_worker *workers;
fac8c35bfb158112226ab43ddf84d59daca5dc30nd /* We have a sticky load balancer
f086b4b402fa9a2fefc7dda85de2a3cc1cd0a654rjung * Update the workers status
727872d18412fc021f03969b8641810d8896820bhumbedooh * so that even session routes get
0d0ba3a410038e179b695446bb149cce6264e0abnd * into account.
727872d18412fc021f03969b8641810d8896820bhumbedooh */
cc7e1025de9ac63bd4db6fe7f71c158b2cf09fe4humbedooh workers = (proxy_worker *)(*balancer)->workers->elts;
0d0ba3a410038e179b695446bb149cce6264e0abnd for (i = 0; i < (*balancer)->workers->nelts; i++) {
cc7e1025de9ac63bd4db6fe7f71c158b2cf09fe4humbedooh /* Take into calculation only the workers that are
727872d18412fc021f03969b8641810d8896820bhumbedooh * not in error state or not disabled.
0d0ba3a410038e179b695446bb149cce6264e0abnd *
0d0ba3a410038e179b695446bb149cce6264e0abnd * TODO: Abstract the below, since this is dependent
0d0ba3a410038e179b695446bb149cce6264e0abnd * on the LB implementation
ac082aefa89416cbdc9a1836eaf3bed9698201c8humbedooh */
0d0ba3a410038e179b695446bb149cce6264e0abnd if (PROXY_WORKER_IS_USABLE(workers)) {
0d0ba3a410038e179b695446bb149cce6264e0abnd workers->s->lbstatus += workers->s->lbfactor;
0d0ba3a410038e179b695446bb149cce6264e0abnd total_factor += workers->s->lbfactor;
727872d18412fc021f03969b8641810d8896820bhumbedooh }
0d0ba3a410038e179b695446bb149cce6264e0abnd workers++;
0d0ba3a410038e179b695446bb149cce6264e0abnd }
30471a4650391f57975f60bbb6e4a90be7b284bfhumbedooh runtime->s->lbstatus -= total_factor;
205f749042ed530040a4f0080dbcb47ceae8a374rjung runtime->s->elected++;
af33a4994ae2ff15bc67d19ff1a7feb906745bf8rbowen
0d0ba3a410038e179b695446bb149cce6264e0abnd *worker = runtime;
7fec19672a491661b2fe4b29f685bc7f4efa64d4nd }
7fec19672a491661b2fe4b29f685bc7f4efa64d4nd else if (route && (*balancer)->sticky_force) {
7fec19672a491661b2fe4b29f685bc7f4efa64d4nd int i, member_of = 0;
5a58787efeb02a1c3f06569d019ad81fd2efa06end proxy_worker *workers;
/*
* We have a route provided that doesn't match the
* balancer name. See if the provider route is the
* member of the same balancer in which case return 503
*/
workers = (proxy_worker *)(*balancer)->workers->elts;
for (i = 0; i < (*balancer)->workers->nelts; i++) {
if (*(workers->s->route) && strcmp(workers->s->route, route) == 0) {
member_of = 1;
break;
}
workers++;
}
if (member_of) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
"proxy: BALANCER: (%s). All workers are in error state for route (%s)",
(*balancer)->name, route);
if ((rv = PROXY_THREAD_UNLOCK(*balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Unlock failed for pre_request",
(*balancer)->name);
}
return HTTP_SERVICE_UNAVAILABLE;
}
}
if ((rv = PROXY_THREAD_UNLOCK(*balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Unlock failed for pre_request",
(*balancer)->name);
}
if (!*worker) {
runtime = find_best_worker(*balancer, r);
if (!runtime) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
"proxy: BALANCER: (%s). All workers are in error state",
(*balancer)->name);
return HTTP_SERVICE_UNAVAILABLE;
}
if ((*balancer)->sticky && runtime) {
/*
* This balancer has sticky sessions and the client either has not
* supplied any routing information or all workers for this route
* including possible redirect and hotstandby workers are in error
* state, but we have found another working worker for this
* balancer where we can send the request. Thus notice that we have
* changed the route to the backend.
*/
apr_table_setn(r->subprocess_env, "BALANCER_ROUTE_CHANGED", "1");
}
*worker = runtime;
}
/* Add balancer/worker info to env. */
apr_table_setn(r->subprocess_env,
"BALANCER_NAME", (*balancer)->name);
apr_table_setn(r->subprocess_env,
"BALANCER_WORKER_NAME", (*worker)->name);
apr_table_setn(r->subprocess_env,
"BALANCER_WORKER_ROUTE", (*worker)->s->route);
/* Rewrite the url from 'balancer://url'
* to the 'worker_scheme://worker_hostname[:worker_port]/url'
* This replaces the balancers fictional name with the
* real hostname of the elected worker.
*/
access_status = rewrite_url(r, *worker, url);
/* Add the session route to request notes if present */
if (route) {
apr_table_setn(r->notes, "session-sticky", sticky);
apr_table_setn(r->notes, "session-route", route);
/* Add session info to env. */
apr_table_setn(r->subprocess_env,
"BALANCER_SESSION_STICKY", sticky);
apr_table_setn(r->subprocess_env,
"BALANCER_SESSION_ROUTE", route);
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy: BALANCER (%s) worker (%s) rewritten to %s",
(*balancer)->name, (*worker)->name, *url);
return access_status;
}
static int proxy_balancer_post_request(proxy_worker *worker,
proxy_balancer *balancer,
request_rec *r,
proxy_server_conf *conf)
{
#if 0
apr_status_t rv;
if ((rv = PROXY_THREAD_LOCK(balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Lock failed for post_request",
balancer->name);
return HTTP_INTERNAL_SERVER_ERROR;
}
/* TODO: placeholder for post_request actions
*/
if ((rv = PROXY_THREAD_UNLOCK(balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Unlock failed for post_request",
balancer->name);
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy_balancer_post_request for (%s)", balancer->name);
#endif
return OK;
}
static void recalc_factors(proxy_balancer *balancer)
{
int i;
proxy_worker *workers;
/* Recalculate lbfactors */
workers = (proxy_worker *)balancer->workers->elts;
/* Special case if there is only one worker it's
* load factor will always be 1
*/
if (balancer->workers->nelts == 1) {
workers->s->lbstatus = workers->s->lbfactor = 1;
return;
}
for (i = 0; i < balancer->workers->nelts; i++) {
/* Update the status entries */
workers[i].s->lbstatus = workers[i].s->lbfactor;
}
}
/* Manages the loadfactors and member status
*/
static int balancer_handler(request_rec *r)
{
void *sconf = r->server->module_config;
proxy_server_conf *conf = (proxy_server_conf *)
ap_get_module_config(sconf, &proxy_module);
proxy_balancer *balancer, *bsel = NULL;
proxy_worker *worker, *wsel = NULL;
apr_table_t *params = apr_table_make(r->pool, 10);
int access_status;
int i, n;
const char *name;
/* is this for us? */
if (strcmp(r->handler, "balancer-manager"))
return DECLINED;
r->allowed = (AP_METHOD_BIT << M_GET);
if (r->method_number != M_GET)
return DECLINED;
if (r->args) {
char *args = apr_pstrdup(r->pool, r->args);
char *tok, *val;
while (args && *args) {
if ((val = ap_strchr(args, '='))) {
*val++ = '\0';
if ((tok = ap_strchr(val, '&')))
*tok++ = '\0';
/*
* Special case: workers are allowed path information
*/
if ((access_status = ap_unescape_url(val)) != OK)
if (strcmp(args, "w") || (access_status != HTTP_NOT_FOUND))
return access_status;
apr_table_setn(params, args, val);
args = tok;
}
else
return HTTP_BAD_REQUEST;
}
}
if ((name = apr_table_get(params, "b")))
bsel = ap_proxy_get_balancer(r->pool, conf,
apr_pstrcat(r->pool, "balancer://", name, NULL));
if ((name = apr_table_get(params, "w"))) {
proxy_worker *ws;
ws = ap_proxy_get_worker(r->pool, conf, name);
if (ws) {
worker = (proxy_worker *)bsel->workers->elts;
for (n = 0; n < bsel->workers->nelts; n++) {
if (strcasecmp(worker->name, ws->name) == 0) {
wsel = worker;
break;
}
++worker;
}
}
}
/* First set the params */
/*
* Note that it is not possible set the proxy_balancer because it is not
* in shared memory.
*/
if (wsel) {
const char *val;
if ((val = apr_table_get(params, "lf"))) {
int ival = atoi(val);
if (ival >= 1 && ival <= 100) {
wsel->s->lbfactor = ival;
if (bsel)
recalc_factors(bsel);
}
}
if ((val = apr_table_get(params, "wr"))) {
if (strlen(val) && strlen(val) < PROXY_WORKER_MAX_ROUTE_SIZ)
strcpy(wsel->s->route, val);
else
*wsel->s->route = '\0';
}
if ((val = apr_table_get(params, "rr"))) {
if (strlen(val) && strlen(val) < PROXY_WORKER_MAX_ROUTE_SIZ)
strcpy(wsel->s->redirect, val);
else
*wsel->s->redirect = '\0';
}
if ((val = apr_table_get(params, "dw"))) {
if (!strcasecmp(val, "Disable"))
wsel->s->status |= PROXY_WORKER_DISABLED;
else if (!strcasecmp(val, "Enable"))
wsel->s->status &= ~PROXY_WORKER_DISABLED;
}
if ((val = apr_table_get(params, "ls"))) {
int ival = atoi(val);
if (ival >= 0 && ival <= 99) {
wsel->s->lbset = ival;
}
}
}
if (apr_table_get(params, "xml")) {
ap_set_content_type(r, "text/xml");
ap_rputs("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n", r);
ap_rputs("<httpd:manager xmlns:httpd=\"http://httpd.apache.org\">\n", r);
ap_rputs(" <httpd:balancers>\n", r);
balancer = (proxy_balancer *)conf->balancers->elts;
for (i = 0; i < conf->balancers->nelts; i++) {
ap_rputs(" <httpd:balancer>\n", r);
ap_rvputs(r, " <httpd:name>", balancer->name, "</httpd:name>\n", NULL);
ap_rputs(" <httpd:workers>\n", r);
worker = (proxy_worker *)balancer->workers->elts;
for (n = 0; n < balancer->workers->nelts; n++) {
ap_rputs(" <httpd:worker>\n", r);
ap_rvputs(r, " <httpd:scheme>", worker->scheme,
"</httpd:scheme>\n", NULL);
ap_rvputs(r, " <httpd:hostname>", worker->hostname,
"</httpd:hostname>\n", NULL);
ap_rprintf(r, " <httpd:loadfactor>%d</httpd:loadfactor>\n",
worker->s->lbfactor);
ap_rputs(" </httpd:worker>\n", r);
++worker;
}
ap_rputs(" </httpd:workers>\n", r);
ap_rputs(" </httpd:balancer>\n", r);
++balancer;
}
ap_rputs(" </httpd:balancers>\n", r);
ap_rputs("</httpd:manager>", r);
}
else {
ap_set_content_type(r, "text/html");
ap_rputs(DOCTYPE_HTML_3_2
"<html><head><title>Balancer Manager</title></head>\n", r);
ap_rputs("<body><h1>Load Balancer Manager for ", r);
ap_rvputs(r, ap_get_server_name(r), "</h1>\n\n", NULL);
ap_rvputs(r, "<dl><dt>Server Version: ",
ap_get_server_description(), "</dt>\n", NULL);
ap_rvputs(r, "<dt>Server Built: ",
ap_get_server_built(), "\n</dt></dl>\n", NULL);
balancer = (proxy_balancer *)conf->balancers->elts;
for (i = 0; i < conf->balancers->nelts; i++) {
ap_rputs("<hr />\n<h3>LoadBalancer Status for ", r);
ap_rvputs(r, balancer->name, "</h3>\n\n", NULL);
ap_rputs("\n\n<table border=\"0\" style=\"text-align: left;\"><tr>"
"<th>StickySession</th><th>Timeout</th><th>FailoverAttempts</th><th>Method</th>"
"</tr>\n<tr>", r);
if (balancer->sticky) {
if (strcmp(balancer->sticky, balancer->sticky_path)) {
ap_rvputs(r, "<td>", balancer->sticky, " | ",
balancer->sticky_path, NULL);
}
else {
ap_rvputs(r, "<td>", balancer->sticky, NULL);
}
}
else {
ap_rputs("<td> - ", r);
}
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->name);
ap_rputs("</table>\n<br />", r);
ap_rputs("\n\n<table border=\"0\" style=\"text-align: left;\"><tr>"
"<th>Worker URL</th>"
"<th>Route</th><th>RouteRedir</th>"
"<th>Factor</th><th>Set</th><th>Status</th>"
"<th>Elected</th><th>To</th><th>From</th>"
"</tr>\n", r);
worker = (proxy_worker *)balancer->workers->elts;
for (n = 0; n < balancer->workers->nelts; n++) {
char fbuf[50];
ap_rvputs(r, "<tr>\n<td><a href=\"", r->uri, "?b=",
balancer->name + sizeof("balancer://") - 1, "&w=",
ap_escape_uri(r->pool, worker->name),
"\">", NULL);
ap_rvputs(r, worker->name, "</a></td>", NULL);
ap_rvputs(r, "<td>", worker->s->route, NULL);
ap_rvputs(r, "</td><td>", worker->s->redirect, NULL);
ap_rprintf(r, "</td><td>%d</td>", worker->s->lbfactor);
ap_rprintf(r, "<td>%d</td><td>", worker->s->lbset);
if (worker->s->status & PROXY_WORKER_DISABLED)
ap_rputs("Dis ", r);
if (worker->s->status & PROXY_WORKER_IN_ERROR)
ap_rputs("Err ", r);
if (worker->s->status & PROXY_WORKER_STOPPED)
ap_rputs("Stop ", r);
if (worker->s->status & PROXY_WORKER_HOT_STANDBY)
ap_rputs("Stby ", r);
if (PROXY_WORKER_IS_USABLE(worker))
ap_rputs("Ok", r);
if (!PROXY_WORKER_IS_INITIALIZED(worker))
ap_rputs("-", r);
ap_rputs("</td>", r);
ap_rprintf(r, "<td>%" APR_SIZE_T_FMT "</td><td>", worker->s->elected);
ap_rputs(apr_strfsize(worker->s->transferred, fbuf), r);
ap_rputs("</td><td>", r);
ap_rputs(apr_strfsize(worker->s->read, fbuf), r);
ap_rputs("</td></tr>\n", r);
++worker;
}
ap_rputs("</table>\n", r);
++balancer;
}
ap_rputs("<hr />\n", r);
if (wsel && bsel) {
ap_rputs("<h3>Edit worker settings for ", r);
ap_rvputs(r, wsel->name, "</h3>\n", NULL);
ap_rvputs(r, "<form method=\"GET\" action=\"", NULL);
ap_rvputs(r, r->uri, "\">\n<dl>", NULL);
ap_rputs("<table><tr><td>Load factor:</td><td><input name=\"lf\" type=text ", r);
ap_rprintf(r, "value=\"%d\"></td></tr>\n", wsel->s->lbfactor);
ap_rputs("<tr><td>LB Set:</td><td><input name=\"ls\" type=text ", r);
ap_rprintf(r, "value=\"%d\"></td></tr>\n", wsel->s->lbset);
ap_rputs("<tr><td>Route:</td><td><input name=\"wr\" type=text ", r);
ap_rvputs(r, "value=\"", wsel->s->route, NULL);
ap_rputs("\"></td></tr>\n", r);
ap_rputs("<tr><td>Route Redirect:</td><td><input name=\"rr\" type=text ", r);
ap_rvputs(r, "value=\"", wsel->s->redirect, NULL);
ap_rputs("\"></td></tr>\n", r);
ap_rputs("<tr><td>Status:</td><td>Disabled: <input name=\"dw\" value=\"Disable\" type=radio", r);
if (wsel->s->status & PROXY_WORKER_DISABLED)
ap_rputs(" checked", r);
ap_rputs("> | Enabled: <input name=\"dw\" value=\"Enable\" type=radio", r);
if (!(wsel->s->status & PROXY_WORKER_DISABLED))
ap_rputs(" checked", r);
ap_rputs("></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=\"w\" ", NULL);
ap_rvputs(r, "value=\"", ap_escape_uri(r->pool, wsel->name), "\">\n", NULL);
ap_rvputs(r, "<input type=hidden name=\"b\" ", NULL);
ap_rvputs(r, "value=\"", bsel->name + sizeof("balancer://") - 1,
"\">\n</form>\n", NULL);
ap_rputs("<hr />\n", r);
}
ap_rputs(ap_psignature("",r), r);
ap_rputs("</body></html>\n", r);
}
return OK;
}
static void child_init(apr_pool_t *p, server_rec *s)
{
while (s) {
void *sconf = s->module_config;
proxy_server_conf *conf;
proxy_balancer *balancer;
int i;
conf = (proxy_server_conf *)ap_get_module_config(sconf, &proxy_module);
/* Initialize shared scoreboard data */
balancer = (proxy_balancer *)conf->balancers->elts;
for (i = 0; i < conf->balancers->nelts; i++) {
init_balancer_members(conf, s, balancer);
balancer++;
}
s = s->next;
}
}
/*
* 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".
*
* lbstatus is "how urgent this worker has to work to fulfill its quota
* of work".
*
* We distribute each worker's work quota to the worker, and then look
* which of them needs to work most urgently (biggest lbstatus). This
* worker is then selected for work, and its lbstatus reduced by the
* total work quota we distributed to all workers. Thus the sum of all
* lbstatus does not change.(*)
*
* If some workers are disabled, the others will
* still be scheduled correctly.
*
* If a balancer is configured as follows:
*
* worker a b c d
* lbfactor 25 25 25 25
*
* And b gets disabled, the following schedule is produced:
*
* a c d a c d a c d ...
*
* Note that the above lbfactor setting is the *exact* same as:
*
* worker a b c d
* lbfactor 1 1 1 1
*
* Asymmetric configurations work as one would expect. For
* example:
*
* worker a b c d
* lbfactor 1 1 1 2
*
* would have a, b and c all handling about the same
* amount of load with d handling twice what a or b
* or c handles individually. So we could see:
*
* b a d c d a c d b d ...
*
*/
static proxy_worker *find_best_byrequests(proxy_balancer *balancer,
request_rec *r)
{
int i;
int total_factor = 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 byrequests 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)) {
worker->s->lbstatus += worker->s->lbfactor;
total_factor += worker->s->lbfactor;
if (!mycandidate || worker->s->lbstatus > mycandidate->s->lbstatus)
mycandidate = worker;
}
}
checked_standby = checking_standby++;
}
cur_lbset++;
} while (cur_lbset <= max_lbset && !mycandidate);
if (mycandidate) {
mycandidate->s->lbstatus -= total_factor;
}
return mycandidate;
}
/*
* 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);
return mycandidate;
}
/*
* How to add additional lbmethods:
* 1. Create func which determines "best" candidate worker
* (eg: find_best_bytraffic, above)
* 2. Register it as a provider.
*/
static const proxy_balancer_method byrequests =
{
"byrequests",
&find_best_byrequests,
NULL
};
static const proxy_balancer_method bytraffic =
{
"bytraffic",
&find_best_bytraffic,
NULL
};
static void ap_proxy_balancer_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
*/
static const char *const aszPred[] = { "mpm_winnt.c", "mod_proxy.c", NULL};
/* manager handler */
ap_hook_handler(balancer_handler, NULL, NULL, APR_HOOK_FIRST);
ap_hook_child_init(child_init, aszPred, NULL, APR_HOOK_MIDDLE);
proxy_hook_pre_request(proxy_balancer_pre_request, NULL, NULL, APR_HOOK_FIRST);
proxy_hook_post_request(proxy_balancer_post_request, NULL, NULL, APR_HOOK_FIRST);
proxy_hook_canon_handler(proxy_balancer_canon, NULL, NULL, APR_HOOK_FIRST);
ap_register_provider(p, PROXY_LBMETHOD, "bytraffic", "0", &bytraffic);
ap_register_provider(p, PROXY_LBMETHOD, "byrequests", "0", &byrequests);
}
module AP_MODULE_DECLARE_DATA proxy_balancer_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 */
ap_proxy_balancer_register_hook /* register hooks */
};