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-rw-r--r--modules/cluster/mod_heartbeat.c228
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
+};