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/* 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
};
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