+++ /dev/null
-/* 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_heartbeat_module;
-
-typedef struct lb_hb_ctx_t
-{
- const char *path;
-} lb_hb_ctx_t;
-
-typedef struct hb_server_t {
- const char *ip;
- int busy;
- int ready;
- int seen;
- proxy_worker *worker;
-} hb_server_t;
-
-static void
-argstr_to_table(apr_pool_t *p, char *str, apr_table_t *parms)
-{
- char *key;
- char *value;
- char *strtok_state;
-
- key = apr_strtok(str, "&", &strtok_state);
- while (key) {
- value = strchr(key, '=');
- if (value) {
- *value = '\0'; /* Split the string in two */
- value++; /* Skip passed the = */
- }
- else {
- value = "1";
- }
- ap_unescape_url(key);
- ap_unescape_url(value);
- apr_table_set(parms, key, value);
- /*
- ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
- "Found query arg: %s = %s", key, value);
- */
- key = apr_strtok(NULL, "&", &strtok_state);
- }
-}
-
-static apr_status_t read_heartbeats(const char *path, apr_hash_t *servers,
- apr_pool_t *pool)
-{
- apr_finfo_t fi;
- apr_status_t rv;
- apr_file_t *fp;
-
- if (!path) {
- return APR_SUCCESS;
- }
-
- rv = apr_file_open(&fp, path, APR_READ|APR_BINARY|APR_BUFFERED,
- APR_OS_DEFAULT, pool);
-
- if (rv) {
- return rv;
- }
-
- rv = apr_file_info_get(&fi, APR_FINFO_SIZE, fp);
-
- if (rv) {
- return rv;
- }
-
- {
- char *t;
- int lineno = 0;
- apr_bucket_alloc_t *ba = apr_bucket_alloc_create(pool);
- apr_bucket_brigade *bb = apr_brigade_create(pool, ba);
- apr_bucket_brigade *tmpbb = apr_brigade_create(pool, ba);
- apr_table_t *hbt = apr_table_make(pool, 10);
-
- apr_brigade_insert_file(bb, fp, 0, fi.size, pool);
-
- do {
- hb_server_t *server;
- char buf[4096];
- apr_size_t bsize = sizeof(buf);
-
- apr_brigade_cleanup(tmpbb);
-
- if (APR_BRIGADE_EMPTY(bb)) {
- break;
- }
-
- rv = apr_brigade_split_line(tmpbb, bb,
- APR_BLOCK_READ, sizeof(buf));
- lineno++;
-
- if (rv) {
- return rv;
- }
-
- apr_brigade_flatten(tmpbb, buf, &bsize);
-
- if (bsize == 0) {
- break;
- }
-
- buf[bsize - 1] = 0;
-
- /* comment */
- if (buf[0] == '#') {
- continue;
- }
-
- /* line format: <IP> <query_string>\n */
- t = strchr(buf, ' ');
- if (!t) {
- continue;
- }
-
- const char *ip = apr_pstrndup(pool, buf, t - buf);
- t++;
-
- server = apr_hash_get(servers, ip, APR_HASH_KEY_STRING);
-
- if (server == NULL) {
- server = apr_pcalloc(pool, sizeof(hb_server_t));
- server->ip = ip;
- server->seen = -1;
-
- apr_hash_set(servers, server->ip, APR_HASH_KEY_STRING, server);
- }
-
- apr_table_clear(hbt);
-
- argstr_to_table(pool, apr_pstrdup(pool, t), hbt);
-
- if (apr_table_get(hbt, "busy")) {
- server->busy = atoi(apr_table_get(hbt, "busy"));
- }
-
- if (apr_table_get(hbt, "ready")) {
- server->ready = atoi(apr_table_get(hbt, "ready"));
- }
-
- if (apr_table_get(hbt, "lastseen")) {
- server->seen = atoi(apr_table_get(hbt, "lastseen"));
- }
-
- if (server->busy == 0 && server->ready != 0) {
- /* Server has zero threads active, but lots of them ready,
- * it likely just started up, so lets /4 the number ready,
- * to prevent us from completely flooding it with all new
- * requests.
- */
- server->ready = server->ready / 4;
- }
-
- } while (1);
- }
-
- return APR_SUCCESS;
-}
-
-/*
- * Finding a random number in a range.
- * n' = a + n(b-a+1)/(M+1)
- * where:
- * n' = random number in range
- * a = low end of range
- * b = high end of range
- * n = random number of 0..M
- * M = maxint
- * Algorithm 'borrowed' from PHP's rand() function.
- */
-#define RAND_RANGE(__n, __min, __max, __tmax) \
-(__n) = (__min) + (long) ((double) ((__max) - (__min) + 1.0) * ((__n) / ((__tmax) + 1.0)))
-
-static apr_status_t random_pick(apr_uint32_t *number,
- apr_uint32_t min,
- apr_uint32_t max)
-{
- apr_status_t rv =
- apr_generate_random_bytes((void*)number, sizeof(apr_uint32_t));
-
- if (rv) {
- return rv;
- }
-
- RAND_RANGE(*number, min, max, APR_UINT32_MAX);
-
- return APR_SUCCESS;
-}
-
-static proxy_worker *find_best_hb(proxy_balancer *balancer,
- request_rec *r)
-{
- apr_status_t rv;
- int i;
- apr_uint32_t openslots = 0;
- proxy_worker *worker;
- hb_server_t *server;
- apr_array_header_t *up_servers;
- proxy_worker *mycandidate = NULL;
- apr_pool_t *tpool;
- apr_hash_t *servers;
-
- lb_hb_ctx_t *ctx =
- ap_get_module_config(r->server->module_config,
- &lbmethod_heartbeat_module);
-
- apr_pool_create(&tpool, r->pool);
-
- servers = apr_hash_make(tpool);
-
- rv = read_heartbeats(ctx->path, servers, tpool);
-
- if (rv) {
- ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
- "lb_heartbeat: Unable to read heartbeats at '%s'",
- ctx->path);
- apr_pool_destroy(tpool);
- return NULL;
- }
-
- up_servers = apr_array_make(tpool, apr_hash_count(servers), sizeof(hb_server_t *));
-
- for (i = 0; i < balancer->workers->nelts; i++) {
- worker = &APR_ARRAY_IDX(balancer->workers, i, proxy_worker);
- server = apr_hash_get(servers, worker->hostname, APR_HASH_KEY_STRING);
-
- if (!server) {
- continue;
- }
-
- if (!PROXY_WORKER_IS_USABLE(worker)) {
- ap_proxy_retry_worker("BALANCER", worker, r->server);
- }
-
- if (PROXY_WORKER_IS_USABLE(worker)) {
- server->worker = worker;
- if (server->seen < 10) {
- openslots += server->ready;
- APR_ARRAY_PUSH(up_servers, hb_server_t *) = server;
- }
- }
- }
-
- if (openslots > 0) {
- apr_uint32_t c = 0;
- apr_uint32_t pick = 0;;
-
- rv = random_pick(&pick, 0, openslots);
-
- if (rv) {
- ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
- "lb_heartbeat: failed picking a random number. how random.");
- apr_pool_destroy(tpool);
- return NULL;
- }
-
- for (i = 0; i < up_servers->nelts; i++) {
- server = APR_ARRAY_IDX(up_servers, i, hb_server_t *);
- if (pick > c && pick <= c + server->ready) {
- mycandidate = server->worker;
- }
-
- c += server->ready;
- }
- }
-
- apr_pool_destroy(tpool);
-
- return mycandidate;
-}
-
-static const proxy_balancer_method heartbeat =
-{
- "heartbeat",
- &find_best_hb,
- NULL
-};
-
-static void register_hooks(apr_pool_t *p)
-{
- ap_register_provider(p, PROXY_LBMETHOD, "heartbeat", "0", &heartbeat);
-}
-
-static void *lb_hb_create_config(apr_pool_t *p, server_rec *s)
-{
- lb_hb_ctx_t *ctx = (lb_hb_ctx_t *) apr_palloc(p, sizeof(lb_hb_ctx_t));
-
- ctx->path = ap_server_root_relative(p, "logs/hb.dat");
-
- return ctx;
-}
-
-static void *lb_hb_merge_config(apr_pool_t *p, void *basev, void *overridesv)
-{
- lb_hb_ctx_t *ps = apr_pcalloc(p, sizeof(lb_hb_ctx_t));
- lb_hb_ctx_t *base = (lb_hb_ctx_t *) basev;
- lb_hb_ctx_t *overrides = (lb_hb_ctx_t *) overridesv;
-
- if (overrides->path) {
- ps->path = apr_pstrdup(p, overrides->path);
- }
- else {
- ps->path = apr_pstrdup(p, base->path);
- }
-
- return ps;
-}
-
-static const char *cmd_lb_hb_storage(cmd_parms *cmd,
- void *dconf, const char *path)
-{
- apr_pool_t *p = cmd->pool;
- lb_hb_ctx_t *ctx =
- (lb_hb_ctx_t *) ap_get_module_config(cmd->server->module_config,
- &lbmethod_heartbeat_module);
-
- const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
-
- if (err != NULL) {
- return err;
- }
-
- ctx->path = ap_server_root_relative(p, path);
-
- return NULL;
-}
-
-static const command_rec cmds[] = {
- AP_INIT_TAKE1("HeartbeatStorage", cmd_lb_hb_storage, NULL, RSRC_CONF,
- "Path to read heartbeat data."),
- {NULL}
-};
-
-module AP_MODULE_DECLARE_DATA lbmethod_heartbeat_module = {
- STANDARD20_MODULE_STUFF,
- NULL, /* create per-directory config structure */
- NULL, /* merge per-directory config structures */
- lb_hb_create_config, /* create per-server config structure */
- lb_hb_merge_config, /* merge per-server config structures */
- cmds, /* command apr_table_t */
- register_hooks /* register hooks */
-};
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