diff options
Diffstat (limited to 'modules/cluster/mod_heartbeat.c')
| -rw-r--r-- | modules/cluster/mod_heartbeat.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/modules/cluster/mod_heartbeat.c b/modules/cluster/mod_heartbeat.c new file mode 100644 index 0000000..1dc4a91 --- /dev/null +++ b/modules/cluster/mod_heartbeat.c @@ -0,0 +1,228 @@ +/* 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 "httpd.h" +#include "http_config.h" +#include "http_log.h" +#include "apr_strings.h" + +#include "ap_mpm.h" +#include "scoreboard.h" +#include "mod_watchdog.h" + +#ifndef HEARTBEAT_INTERVAL +#define HEARTBEAT_INTERVAL (1) +#endif + +module AP_MODULE_DECLARE_DATA heartbeat_module; + +typedef struct hb_ctx_t +{ + int active; + apr_sockaddr_t *mcast_addr; + int server_limit; + int thread_limit; + apr_status_t status; +} hb_ctx_t; + +static const char *msg_format = "v=%u&ready=%u&busy=%u"; + +#define MSG_VERSION (1) + +static int hb_monitor(hb_ctx_t *ctx, apr_pool_t *p) +{ + apr_size_t len; + apr_socket_t *sock = NULL; + char buf[256]; + int i, j; + apr_uint32_t ready = 0; + apr_uint32_t busy = 0; + ap_generation_t mpm_generation; + + ap_mpm_query(AP_MPMQ_GENERATION, &mpm_generation); + + for (i = 0; i < ctx->server_limit; i++) { + process_score *ps; + ps = ap_get_scoreboard_process(i); + + for (j = 0; j < ctx->thread_limit; j++) { + int res; + + worker_score *ws = NULL; + + ws = &ap_scoreboard_image->servers[i][j]; + + res = ws->status; + + if (res == SERVER_READY && ps->generation == mpm_generation) { + ready++; + } + else if (res != SERVER_DEAD && + res != SERVER_STARTING && res != SERVER_IDLE_KILL && + ps->generation == mpm_generation) { + busy++; + } + } + } + + len = apr_snprintf(buf, sizeof(buf), msg_format, MSG_VERSION, ready, busy); + + do { + apr_status_t rv; + rv = apr_socket_create(&sock, ctx->mcast_addr->family, + SOCK_DGRAM, APR_PROTO_UDP, p); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_WARNING, rv, + NULL, APLOGNO(02097) "Heartbeat: apr_socket_create failed"); + break; + } + + rv = apr_mcast_loopback(sock, 1); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_WARNING, rv, + NULL, APLOGNO(02098) "Heartbeat: apr_mcast_loopback failed"); + break; + } + + rv = apr_socket_sendto(sock, ctx->mcast_addr, 0, buf, &len); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_WARNING, rv, + NULL, APLOGNO(02099) "Heartbeat: apr_socket_sendto failed"); + break; + } + } while (0); + + if (sock) { + apr_socket_close(sock); + } + + return OK; +} + +static int hb_watchdog_init(server_rec *s, const char *name, apr_pool_t *pool) +{ + hb_ctx_t *ctx = ap_get_module_config(s->module_config, &heartbeat_module); + + ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &ctx->thread_limit); + ap_mpm_query(AP_MPMQ_HARD_LIMIT_DAEMONS, &ctx->server_limit); + + return OK; +} + +static int hb_watchdog_exit(server_rec *s, const char *name, apr_pool_t *pool) +{ + return OK; +} + +static int hb_watchdog_step(server_rec *s, const char *name, apr_pool_t *pool) +{ + hb_ctx_t *ctx = ap_get_module_config(s->module_config, &heartbeat_module); + + if (!ctx->active || strcmp(name, AP_WATCHDOG_SINGLETON)) { + return OK; + } + return hb_monitor(ctx, pool); +} + +static int hb_watchdog_need(server_rec *s, const char *name, + int parent, int singleton) +{ + hb_ctx_t *ctx = ap_get_module_config(s->module_config, &heartbeat_module); + + if (ctx->active && singleton && !strcmp(name, AP_WATCHDOG_SINGLETON)) + return OK; + else + return DECLINED; +} + +static void hb_register_hooks(apr_pool_t *p) +{ + ap_hook_watchdog_need(hb_watchdog_need, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_watchdog_init(hb_watchdog_init, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_watchdog_step(hb_watchdog_step, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_watchdog_exit(hb_watchdog_exit, NULL, NULL, APR_HOOK_MIDDLE); +} + +static void *hb_create_config(apr_pool_t *p, server_rec *s) +{ + hb_ctx_t *cfg = (hb_ctx_t *) apr_pcalloc(p, sizeof(hb_ctx_t)); + + return cfg; +} + +static const char *cmd_hb_address(cmd_parms *cmd, + void *dconf, const char *addr) +{ + apr_status_t rv; + char *host_str; + char *scope_id; + apr_port_t port = 0; + apr_pool_t *p = cmd->pool; + hb_ctx_t *ctx = + (hb_ctx_t *) ap_get_module_config(cmd->server->module_config, + &heartbeat_module); + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + + if (err != NULL) { + return err; + } + + if (!ctx->active) { + ctx->active = 1; + } + else { + return "HeartbeatAddress: May only be specified once."; + } + + rv = apr_parse_addr_port(&host_str, &scope_id, &port, addr, cmd->temp_pool); + + if (rv) { + return "HeartbeatAddress: Unable to parse address."; + } + + if (host_str == NULL) { + return "HeartbeatAddress: No host provided in address"; + } + + if (port == 0) { + return "HeartbeatAddress: No port provided in address"; + } + + rv = apr_sockaddr_info_get(&ctx->mcast_addr, host_str, APR_INET, port, 0, + p); + + if (rv) { + return "HeartbeatAddress: apr_sockaddr_info_get failed."; + } + + return NULL; +} + +static const command_rec hb_cmds[] = { + AP_INIT_TAKE1("HeartbeatAddress", cmd_hb_address, NULL, RSRC_CONF, + "Address to send heartbeat requests"), + {NULL} +}; + +AP_DECLARE_MODULE(heartbeat) = { + STANDARD20_MODULE_STUFF, + NULL, /* create per-directory config structure */ + NULL, /* merge per-directory config structures */ + hb_create_config, /* create per-server config structure */ + NULL, /* merge per-server config structures */ + hb_cmds, /* command apr_table_t */ + hb_register_hooks +}; |