diff options
Diffstat (limited to '')
| -rw-r--r-- | modules/cluster/mod_heartmonitor.c | 918 |
1 files changed, 918 insertions, 0 deletions
diff --git a/modules/cluster/mod_heartmonitor.c b/modules/cluster/mod_heartmonitor.c new file mode 100644 index 0000000..965fef5 --- /dev/null +++ b/modules/cluster/mod_heartmonitor.c @@ -0,0 +1,918 @@ +/* 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 "http_core.h" +#include "http_protocol.h" +#include "apr_strings.h" +#include "apr_hash.h" +#include "apr_time.h" +#include "ap_mpm.h" +#include "scoreboard.h" +#include "mod_watchdog.h" +#include "ap_slotmem.h" +#include "heartbeat.h" + + +#ifndef HM_UPDATE_SEC +/* How often we update the stats file */ +/* TODO: Make a runtime config */ +#define HM_UPDATE_SEC (5) +#endif + +#define HM_WATHCHDOG_NAME ("_heartmonitor_") + +static const ap_slotmem_provider_t *storage = NULL; +static ap_slotmem_instance_t *slotmem = NULL; +static int maxworkers = 0; + +module AP_MODULE_DECLARE_DATA heartmonitor_module; + +typedef struct hm_server_t +{ + const char *ip; + int busy; + int ready; + unsigned int port; + apr_time_t seen; +} hm_server_t; + +typedef struct hm_ctx_t +{ + int active; + const char *storage_path; + ap_watchdog_t *watchdog; + apr_interval_time_t interval; + apr_sockaddr_t *mcast_addr; + apr_status_t status; + volatile int keep_running; + apr_socket_t *sock; + apr_pool_t *p; + apr_hash_t *servers; + server_rec *s; +} hm_ctx_t; + +typedef struct hm_slot_server_ctx_t { + hm_server_t *s; + int found; + unsigned int item_id; +} hm_slot_server_ctx_t; + +static apr_status_t hm_listen(hm_ctx_t *ctx) +{ + apr_status_t rv; + + rv = apr_socket_create(&ctx->sock, ctx->mcast_addr->family, + SOCK_DGRAM, APR_PROTO_UDP, ctx->p); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02068) + "Failed to create listening socket."); + return rv; + } + + rv = apr_socket_opt_set(ctx->sock, APR_SO_REUSEADDR, 1); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02069) + "Failed to set APR_SO_REUSEADDR to 1 on socket."); + return rv; + } + + + rv = apr_socket_opt_set(ctx->sock, APR_SO_NONBLOCK, 1); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02070) + "Failed to set APR_SO_NONBLOCK to 1 on socket."); + return rv; + } + + rv = apr_socket_bind(ctx->sock, ctx->mcast_addr); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02071) + "Failed to bind on socket."); + return rv; + } + + rv = apr_mcast_join(ctx->sock, ctx->mcast_addr, NULL, NULL); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02072) + "Failed to join multicast group"); + return rv; + } + + rv = apr_mcast_loopback(ctx->sock, 1); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02073) + "Failed to accept localhost mulitcast on socket."); + return rv; + } + + return APR_SUCCESS; +} + +/* XXX: The same exists in mod_lbmethod_heartbeat.c where it is named argstr_to_table */ +static void qs_to_table(const char *input, apr_table_t *parms, + apr_pool_t *p) +{ + char *key; + char *value; + char *query_string; + char *strtok_state; + + if (input == NULL) { + return; + } + + query_string = apr_pstrdup(p, input); + + key = apr_strtok(query_string, "&", &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, APLOGNO(03182) + "Found query arg: %s = %s", key, value); + */ + key = apr_strtok(NULL, "&", &strtok_state); + } +} + + +#define SEEN_TIMEOUT (30) + +/* Store in the slotmem */ +static apr_status_t hm_update(void* mem, void *data, apr_pool_t *p) +{ + hm_slot_server_t *old = (hm_slot_server_t *) mem; + hm_slot_server_ctx_t *s = (hm_slot_server_ctx_t *) data; + hm_server_t *new = s->s; + if (strncmp(old->ip, new->ip, MAXIPSIZE)==0) { + s->found = 1; + old->busy = new->busy; + old->ready = new->ready; + old->seen = new->seen; + } + return APR_SUCCESS; +} +/* Read the id corresponding to the entry in the slotmem */ +static apr_status_t hm_readid(void* mem, void *data, apr_pool_t *p) +{ + hm_slot_server_t *old = (hm_slot_server_t *) mem; + hm_slot_server_ctx_t *s = (hm_slot_server_ctx_t *) data; + hm_server_t *new = s->s; + if (strncmp(old->ip, new->ip, MAXIPSIZE)==0) { + s->found = 1; + s->item_id = old->id; + } + return APR_SUCCESS; +} +/* update the entry or create it if not existing */ +static apr_status_t hm_slotmem_update_stat(hm_server_t *s, apr_pool_t *pool) +{ + /* We call do_all (to try to update) otherwise grab + put */ + hm_slot_server_ctx_t ctx; + ctx.s = s; + ctx.found = 0; + storage->doall(slotmem, hm_update, &ctx, pool); + if (!ctx.found) { + unsigned int i; + hm_slot_server_t hmserver; + memcpy(hmserver.ip, s->ip, MAXIPSIZE); + hmserver.busy = s->busy; + hmserver.ready = s->ready; + hmserver.seen = s->seen; + /* XXX locking for grab() / put() */ + storage->grab(slotmem, &i); + hmserver.id = i; + storage->put(slotmem, i, (unsigned char *)&hmserver, sizeof(hmserver)); + } + return APR_SUCCESS; +} +static apr_status_t hm_slotmem_remove_stat(hm_server_t *s, apr_pool_t *pool) +{ + hm_slot_server_ctx_t ctx; + ctx.s = s; + ctx.found = 0; + storage->doall(slotmem, hm_readid, &ctx, pool); + if (ctx.found) { + storage->release(slotmem, ctx.item_id); + } + return APR_SUCCESS; +} +static apr_status_t hm_file_update_stat(hm_ctx_t *ctx, hm_server_t *s, apr_pool_t *pool) +{ + apr_status_t rv; + apr_file_t *fp; + apr_file_t *fpin; + apr_time_t now; + apr_time_t fage; + apr_finfo_t fi; + int updated = 0; + char *path = apr_pstrcat(pool, ctx->storage_path, ".tmp.XXXXXX", NULL); + + + /* TODO: Update stats file (!) */ + rv = apr_file_mktemp(&fp, path, APR_CREATE | APR_WRITE, pool); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02074) + "Unable to open tmp file: %s", path); + return rv; + } + rv = apr_file_open(&fpin, ctx->storage_path, APR_READ|APR_BINARY|APR_BUFFERED, + APR_OS_DEFAULT, pool); + + now = apr_time_now(); + if (rv == APR_SUCCESS) { + char *t; + apr_table_t *hbt = apr_table_make(pool, 10); + apr_bucket_alloc_t *ba; + apr_bucket_brigade *bb; + apr_bucket_brigade *tmpbb; + + rv = apr_file_info_get(&fi, APR_FINFO_SIZE | APR_FINFO_MTIME, fpin); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02075) + "Unable to read file: %s", ctx->storage_path); + return rv; + } + + /* Read the file and update the line corresponding to the node */ + ba = apr_bucket_alloc_create(pool); + bb = apr_brigade_create(pool, ba); + apr_brigade_insert_file(bb, fpin, 0, fi.size, pool); + tmpbb = apr_brigade_create(pool, ba); + fage = apr_time_sec(now - fi.mtime); + do { + char buf[4096]; + const char *ip; + 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)); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02076) + "Unable to read from file: %s", ctx->storage_path); + return rv; + } + + apr_brigade_flatten(tmpbb, buf, &bsize); + if (bsize == 0) { + break; + } + buf[bsize - 1] = 0; + t = strchr(buf, ' '); + if (t) { + ip = apr_pstrmemdup(pool, buf, t - buf); + } + else { + ip = NULL; + } + + if (!ip || buf[0] == '#') { + /* copy things we can't process */ + apr_file_printf(fp, "%s\n", buf); + } + else if (strcmp(ip, s->ip) != 0 ) { + hm_server_t node; + apr_time_t seen; + const char *val; + + /* Update seen time according to the last file modification */ + apr_table_clear(hbt); + qs_to_table(apr_pstrdup(pool, t), hbt, pool); + if ((val = apr_table_get(hbt, "busy"))) { + node.busy = atoi(val); + } + else { + node.busy = 0; + } + + if ((val = apr_table_get(hbt, "ready"))) { + node.ready = atoi(val); + } + else { + node.ready = 0; + } + + if ((val = apr_table_get(hbt, "lastseen"))) { + node.seen = atoi(val); + } + else { + node.seen = SEEN_TIMEOUT; + } + seen = fage + node.seen; + + if ((val = apr_table_get(hbt, "port"))) { + node.port = atoi(val); + } + else { + node.port = 80; + } + apr_file_printf(fp, "%s &ready=%u&busy=%u&lastseen=%u&port=%u\n", + ip, node.ready, node.busy, (unsigned int) seen, node.port); + } + else { + apr_time_t seen; + seen = apr_time_sec(now - s->seen); + apr_file_printf(fp, "%s &ready=%u&busy=%u&lastseen=%u&port=%u\n", + s->ip, s->ready, s->busy, (unsigned int) seen, s->port); + updated = 1; + } + } while (1); + } + + if (!updated) { + apr_time_t seen; + seen = apr_time_sec(now - s->seen); + apr_file_printf(fp, "%s &ready=%u&busy=%u&lastseen=%u&port=%u\n", + s->ip, s->ready, s->busy, (unsigned int) seen, s->port); + } + + rv = apr_file_flush(fp); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02077) + "Unable to flush file: %s", path); + return rv; + } + + rv = apr_file_close(fp); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02078) + "Unable to close file: %s", path); + return rv; + } + + rv = apr_file_perms_set(path, + APR_FPROT_UREAD | APR_FPROT_GREAD | + APR_FPROT_WREAD); + if (rv && rv != APR_INCOMPLETE && rv != APR_ENOTIMPL) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02079) + "Unable to set file permissions on %s", + path); + return rv; + } + + rv = apr_file_rename(path, ctx->storage_path, pool); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02080) + "Unable to move file: %s -> %s", path, + ctx->storage_path); + return rv; + } + + return APR_SUCCESS; +} +static apr_status_t hm_update_stat(hm_ctx_t *ctx, hm_server_t *s, apr_pool_t *pool) +{ + if (slotmem) + return hm_slotmem_update_stat(s, pool); + else + return hm_file_update_stat(ctx, s, pool); +} + +/* Store in a file */ +static apr_status_t hm_file_update_stats(hm_ctx_t *ctx, apr_pool_t *p) +{ + apr_status_t rv; + apr_file_t *fp; + apr_hash_index_t *hi; + apr_time_t now; + char *path = apr_pstrcat(p, ctx->storage_path, ".tmp.XXXXXX", NULL); + /* TODO: Update stats file (!) */ + rv = apr_file_mktemp(&fp, path, APR_CREATE | APR_WRITE, p); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02081) + "Unable to open tmp file: %s", path); + return rv; + } + + now = apr_time_now(); + for (hi = apr_hash_first(p, ctx->servers); + hi != NULL; hi = apr_hash_next(hi)) { + hm_server_t *s = NULL; + apr_time_t seen; + apr_hash_this(hi, NULL, NULL, (void **) &s); + seen = apr_time_sec(now - s->seen); + if (seen > SEEN_TIMEOUT) { + /* + * Skip this entry from the heartbeat file -- when it comes back, + * we will reuse the memory... + */ + } + else { + apr_file_printf(fp, "%s &ready=%u&busy=%u&lastseen=%u&port=%u\n", + s->ip, s->ready, s->busy, (unsigned int) seen, s->port); + } + } + + rv = apr_file_flush(fp); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02082) + "Unable to flush file: %s", path); + return rv; + } + + rv = apr_file_close(fp); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02083) + "Unable to close file: %s", path); + return rv; + } + + rv = apr_file_perms_set(path, + APR_FPROT_UREAD | APR_FPROT_GREAD | + APR_FPROT_WREAD); + if (rv && rv != APR_INCOMPLETE && rv != APR_ENOTIMPL) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02084) + "Unable to set file permissions on %s", + path); + return rv; + } + + rv = apr_file_rename(path, ctx->storage_path, p); + + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02085) + "Unable to move file: %s -> %s", path, + ctx->storage_path); + return rv; + } + + return APR_SUCCESS; +} +/* Store in a slotmem */ +static apr_status_t hm_slotmem_update_stats(hm_ctx_t *ctx, apr_pool_t *p) +{ + apr_status_t rv; + apr_time_t now; + apr_hash_index_t *hi; + now = apr_time_now(); + for (hi = apr_hash_first(p, ctx->servers); + hi != NULL; hi = apr_hash_next(hi)) { + hm_server_t *s = NULL; + apr_time_t seen; + apr_hash_this(hi, NULL, NULL, (void **) &s); + seen = apr_time_sec(now - s->seen); + if (seen > SEEN_TIMEOUT) { + /* remove it */ + rv = hm_slotmem_remove_stat(s, p); + } else { + /* update it */ + rv = hm_slotmem_update_stat(s, p); + } + if (rv !=APR_SUCCESS) + return rv; + } + return APR_SUCCESS; +} +/* Store/update the stats */ +static apr_status_t hm_update_stats(hm_ctx_t *ctx, apr_pool_t *p) +{ + if (slotmem) + return hm_slotmem_update_stats(ctx, p); + else + return hm_file_update_stats(ctx, p); +} + +static hm_server_t *hm_get_server(hm_ctx_t *ctx, const char *ip, const int port) +{ + hm_server_t *s; + + s = apr_hash_get(ctx->servers, ip, APR_HASH_KEY_STRING); + + if (s == NULL) { + s = apr_palloc(ctx->p, sizeof(hm_server_t)); + s->ip = apr_pstrdup(ctx->p, ip); + s->port = port; + s->ready = 0; + s->busy = 0; + s->seen = 0; + apr_hash_set(ctx->servers, s->ip, APR_HASH_KEY_STRING, s); + } + + return s; +} + +/* Process a message received from a backend node */ +static void hm_processmsg(hm_ctx_t *ctx, apr_pool_t *p, + apr_sockaddr_t *from, char *buf, int len) +{ + apr_table_t *tbl; + + buf[len] = '\0'; + + tbl = apr_table_make(p, 10); + + qs_to_table(buf, tbl, p); + + if (apr_table_get(tbl, "v") != NULL && + apr_table_get(tbl, "busy") != NULL && + apr_table_get(tbl, "ready") != NULL) { + char *ip; + int port = 80; + hm_server_t *s; + /* TODO: REMOVE ME BEFORE PRODUCTION (????) */ + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ctx->s, APLOGNO(02086) + "%pI busy=%s ready=%s", from, + apr_table_get(tbl, "busy"), apr_table_get(tbl, "ready")); + + apr_sockaddr_ip_get(&ip, from); + + if (apr_table_get(tbl, "port") != NULL) + port = atoi(apr_table_get(tbl, "port")); + + s = hm_get_server(ctx, ip, port); + + s->busy = atoi(apr_table_get(tbl, "busy")); + s->ready = atoi(apr_table_get(tbl, "ready")); + s->seen = apr_time_now(); + } + else { + ap_log_error(APLOG_MARK, APLOG_CRIT, 0, ctx->s, APLOGNO(02087) + "malformed message from %pI", + from); + } + +} +/* Read message from multicast socket */ +#define MAX_MSG_LEN (1000) +static apr_status_t hm_recv(hm_ctx_t *ctx, apr_pool_t *p) +{ + char buf[MAX_MSG_LEN + 1]; + apr_sockaddr_t from; + apr_size_t len = MAX_MSG_LEN; + apr_status_t rv; + + from.pool = p; + + rv = apr_socket_recvfrom(&from, ctx->sock, 0, buf, &len); + + if (APR_STATUS_IS_EAGAIN(rv)) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02088) "would block"); + return APR_SUCCESS; + } + else if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02089) "recvfrom failed"); + return rv; + } + + hm_processmsg(ctx, p, &from, buf, len); + + return rv; +} + +static apr_status_t hm_watchdog_callback(int state, void *data, + apr_pool_t *pool) +{ + apr_status_t rv = APR_SUCCESS; + apr_time_t cur, now; + hm_ctx_t *ctx = (hm_ctx_t *)data; + + if (!ctx->active) { + return rv; + } + + switch (state) { + case AP_WATCHDOG_STATE_STARTING: + rv = hm_listen(ctx); + if (rv) { + ctx->status = rv; + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ctx->s, APLOGNO(02090) + "Unable to listen for connections!"); + } + else { + ctx->keep_running = 1; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ctx->s, APLOGNO(02091) + "%s listener started.", + HM_WATHCHDOG_NAME); + } + break; + case AP_WATCHDOG_STATE_RUNNING: + /* store in the slotmem or in the file depending on configuration */ + hm_update_stats(ctx, pool); + cur = now = apr_time_sec(apr_time_now()); + /* TODO: Insted HN_UPDATE_SEC use + * the ctx->interval + */ + while ((now - cur) < apr_time_sec(ctx->interval)) { + int n; + apr_status_t rc; + apr_pool_t *p; + apr_pollfd_t pfd; + apr_interval_time_t timeout; + + apr_pool_create(&p, pool); + + pfd.desc_type = APR_POLL_SOCKET; + pfd.desc.s = ctx->sock; + pfd.p = p; + pfd.reqevents = APR_POLLIN; + + timeout = apr_time_from_sec(1); + + rc = apr_poll(&pfd, 1, &n, timeout); + + if (!ctx->keep_running) { + apr_pool_destroy(p); + break; + } + if (rc == APR_SUCCESS && (pfd.rtnevents & APR_POLLIN)) { + hm_recv(ctx, p); + } + now = apr_time_sec(apr_time_now()); + apr_pool_destroy(p); + } + break; + case AP_WATCHDOG_STATE_STOPPING: + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ctx->s, APLOGNO(02092) + "stopping %s listener.", + HM_WATHCHDOG_NAME); + + ctx->keep_running = 0; + if (ctx->sock) { + apr_socket_close(ctx->sock); + ctx->sock = NULL; + } + break; + } + return rv; +} + +static int hm_post_config(apr_pool_t *p, apr_pool_t *plog, + apr_pool_t *ptemp, server_rec *s) +{ + apr_status_t rv; + hm_ctx_t *ctx = ap_get_module_config(s->module_config, + &heartmonitor_module); + APR_OPTIONAL_FN_TYPE(ap_watchdog_get_instance) *hm_watchdog_get_instance; + APR_OPTIONAL_FN_TYPE(ap_watchdog_register_callback) *hm_watchdog_register_callback; + + hm_watchdog_get_instance = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_get_instance); + hm_watchdog_register_callback = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_register_callback); + if (!hm_watchdog_get_instance || !hm_watchdog_register_callback) { + ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, APLOGNO(02093) + "mod_watchdog is required"); + return !OK; + } + + /* Create the slotmem */ + if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_CONFIG) { + /* this is the real thing */ + if (maxworkers) { + storage = ap_lookup_provider(AP_SLOTMEM_PROVIDER_GROUP, "shm", + AP_SLOTMEM_PROVIDER_VERSION); + if (!storage) { + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02284) + "failed to lookup provider 'shm' for '%s', " + "maybe you need to load mod_slotmem_shm?", + AP_SLOTMEM_PROVIDER_GROUP); + return !OK; + } + storage->create(&slotmem, "mod_heartmonitor", sizeof(hm_slot_server_t), maxworkers, AP_SLOTMEM_TYPE_PREGRAB, p); + if (!slotmem) { + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02285) + "slotmem_create for status failed"); + return !OK; + } + } + } + + if (!ctx->active) { + return OK; + } + rv = hm_watchdog_get_instance(&ctx->watchdog, + HM_WATHCHDOG_NAME, + 0, 1, p); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(02094) + "Failed to create watchdog instance (%s)", + HM_WATHCHDOG_NAME); + return !OK; + } + /* Register a callback with zero interval. */ + rv = hm_watchdog_register_callback(ctx->watchdog, + 0, + ctx, + hm_watchdog_callback); + if (rv) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(02095) + "Failed to register watchdog callback (%s)", + HM_WATHCHDOG_NAME); + return !OK; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02096) + "wd callback %s", HM_WATHCHDOG_NAME); + return OK; +} + +static int hm_handler(request_rec *r) +{ + apr_bucket_brigade *input_brigade; + apr_size_t len; + char *buf; + apr_status_t status; + apr_table_t *tbl; + hm_server_t hmserver; + char *ip; + hm_ctx_t *ctx; + + if (strcmp(r->handler, "heartbeat")) { + return DECLINED; + } + if (r->method_number != M_POST) { + return HTTP_METHOD_NOT_ALLOWED; + } + + len = MAX_MSG_LEN; + ctx = ap_get_module_config(r->server->module_config, + &heartmonitor_module); + + buf = apr_pcalloc(r->pool, MAX_MSG_LEN); + input_brigade = apr_brigade_create(r->connection->pool, r->connection->bucket_alloc); + status = ap_get_brigade(r->input_filters, input_brigade, AP_MODE_READBYTES, APR_BLOCK_READ, MAX_MSG_LEN); + if (status != APR_SUCCESS) { + return ap_map_http_request_error(status, HTTP_BAD_REQUEST); + } + apr_brigade_flatten(input_brigade, buf, &len); + + /* we can't use hm_processmsg because it uses hm_get_server() */ + buf[len] = '\0'; + tbl = apr_table_make(r->pool, 10); + qs_to_table(buf, tbl, r->pool); + apr_sockaddr_ip_get(&ip, r->connection->client_addr); + hmserver.ip = ip; + hmserver.port = 80; + if (apr_table_get(tbl, "port") != NULL) + hmserver.port = atoi(apr_table_get(tbl, "port")); + hmserver.busy = atoi(apr_table_get(tbl, "busy")); + hmserver.ready = atoi(apr_table_get(tbl, "ready")); + hmserver.seen = apr_time_now(); + hm_update_stat(ctx, &hmserver, r->pool); + + ap_set_content_type(r, "text/plain"); + ap_set_content_length(r, 2); + ap_rputs("OK", r); + ap_rflush(r); + + return OK; +} + +static void hm_register_hooks(apr_pool_t *p) +{ + static const char * const aszSucc[]={ "mod_proxy.c", NULL }; + ap_hook_post_config(hm_post_config, NULL, NULL, APR_HOOK_MIDDLE); + + ap_hook_handler(hm_handler, NULL, aszSucc, APR_HOOK_FIRST); +} + +static void *hm_create_config(apr_pool_t *p, server_rec *s) +{ + hm_ctx_t *ctx = (hm_ctx_t *) apr_palloc(p, sizeof(hm_ctx_t)); + + ctx->active = 0; + ctx->storage_path = ap_runtime_dir_relative(p, DEFAULT_HEARTBEAT_STORAGE); + /* TODO: Add directive for tuning the update interval + */ + ctx->interval = apr_time_from_sec(HM_UPDATE_SEC); + ctx->s = s; + apr_pool_create(&ctx->p, p); + ctx->servers = apr_hash_make(ctx->p); + + return ctx; +} + +static const char *cmd_hm_storage(cmd_parms *cmd, + void *dconf, const char *path) +{ + apr_pool_t *p = cmd->pool; + hm_ctx_t *ctx = + (hm_ctx_t *) ap_get_module_config(cmd->server->module_config, + &heartmonitor_module); + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + + if (err != NULL) { + return err; + } + + ctx->storage_path = ap_runtime_dir_relative(p, path); + + return NULL; +} + +static const char *cmd_hm_listen(cmd_parms *cmd, + void *dconf, const char *mcast_addr) +{ + apr_status_t rv; + char *host_str; + char *scope_id; + apr_port_t port = 0; + apr_pool_t *p = cmd->pool; + hm_ctx_t *ctx = + (hm_ctx_t *) ap_get_module_config(cmd->server->module_config, + &heartmonitor_module); + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + + if (err != NULL) { + return err; + } + + if (!ctx->active) { + ctx->active = 1; + } + else { + return "HeartbeatListen: May only be specified once."; + } + + rv = apr_parse_addr_port(&host_str, &scope_id, &port, mcast_addr, cmd->temp_pool); + + if (rv) { + return "HeartbeatListen: Unable to parse multicast address."; + } + + if (host_str == NULL) { + return "HeartbeatListen: No host provided in multicast address"; + } + + if (port == 0) { + return "HeartbeatListen: No port provided in multicast address"; + } + + rv = apr_sockaddr_info_get(&ctx->mcast_addr, host_str, APR_INET, port, 0, + p); + + if (rv) { + return + "HeartbeatListen: apr_sockaddr_info_get failed on multicast address"; + } + + return NULL; +} + +static const char *cmd_hm_maxworkers(cmd_parms *cmd, + void *dconf, const char *data) +{ + const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); + + if (err != NULL) { + return err; + } + + maxworkers = atoi(data); + if (maxworkers <= 10) + return "HeartbeatMaxServers: Should be bigger than 10"; + + return NULL; +} + +static const command_rec hm_cmds[] = { + AP_INIT_TAKE1("HeartbeatListen", cmd_hm_listen, NULL, RSRC_CONF, + "Address to listen for heartbeat requests"), + AP_INIT_TAKE1("HeartbeatStorage", cmd_hm_storage, NULL, RSRC_CONF, + "Path to store heartbeat data."), + AP_INIT_TAKE1("HeartbeatMaxServers", cmd_hm_maxworkers, NULL, RSRC_CONF, + "Max number of servers when using slotmem (instead file) to store heartbeat data."), + {NULL} +}; + +AP_DECLARE_MODULE(heartmonitor) = { + STANDARD20_MODULE_STUFF, + NULL, /* create per-directory config structure */ + NULL, /* merge per-directory config structures */ + hm_create_config, /* create per-server config structure */ + NULL, /* merge per-server config structures */ + hm_cmds, /* command apr_table_t */ + hm_register_hooks +}; 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