/* * This file is distributed as part of the MariaDB Corporation MaxScale. It is free * software: you can redistribute it and/or modify it under the terms of the * GNU General Public License as published by the Free Software Foundation, * version 2. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 51 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * Copyright MariaDB Corporation Ab 2013-2014 */ /** * @file mysql_mon.c - A MySQL replication cluster monitor * * @verbatim * Revision History * * Date Who Description * 08/07/13 Mark Riddoch Initial implementation * 11/07/13 Mark Riddoch Addition of code to check replication * status * 25/07/13 Mark Riddoch Addition of decrypt for passwords and * diagnostic interface * 20/05/14 Massimiliano Pinto Addition of support for MariadDB multimaster replication setup. * New server field version_string is updated. * 28/05/14 Massimiliano Pinto Added set Id and configuration options (setInverval) * Parameters are now printed in diagnostics * 03/06/14 Mark Ridoch Add support for maintenance mode * 17/06/14 Massimiliano Pinto Addition of getServerByNodeId routine * and first implementation for depth of replication for nodes. * 23/06/14 Massimiliano Pinto Added replication consistency after replication tree computation * 27/06/14 Massimiliano Pinto Added replication pending status in monitored server, storing there * the status to update in server status field before * starting the replication consistency check. * This will also give routers a consistent "status" of all servers * 28/08/14 Massimiliano Pinto Added detectStaleMaster feature: previous detected master will be used again, even if the replication is stopped. * This means both IO and SQL threads are not working on slaves. * This option is not enabled by default. * 10/11/14 Massimiliano Pinto Addition of setNetworkTimeout for connect, read, write * 18/11/14 Massimiliano Pinto One server only in configuration becomes master. * servers=server1 must be present in mysql_mon and in router sections as well. * 08/05/15 Markus Makela Added launchable scripts * 17/10/15 Martin Brampton Change DCB callback to hangup * * @endverbatim */ #include #include #include static void monitorMain(void *); static char *version_str = "V1.4.0"; MODULE_INFO info = { MODULE_API_MONITOR, MODULE_GA, MONITOR_VERSION, "A MySQL Master/Slave replication monitor" }; static void *startMonitor(void *, void*); static void stopMonitor(void *); static void diagnostics(DCB *, void *); static void defaultId(void *, unsigned long); static MONITOR_SERVERS *getServerByNodeId(MONITOR_SERVERS *, long); static MONITOR_SERVERS *getSlaveOfNodeId(MONITOR_SERVERS *, long); static MONITOR_SERVERS *get_replication_tree(MONITOR *, int); static void set_master_heartbeat(MYSQL_MONITOR *, MONITOR_SERVERS *); static void set_slave_heartbeat(MONITOR *, MONITOR_SERVERS *); static int add_slave_to_master(long *, int, long); bool isMySQLEvent(monitor_event_t event); void check_maxscale_schema_replication(MONITOR *monitor); static bool report_version_err = true; static const char* hb_table_name = "maxscale_schema.replication_heartbeat"; static MONITOR_OBJECT MyObject = { startMonitor, stopMonitor, diagnostics }; /** * Implementation of the mandatory version entry point * * @return version string of the module */ char * version() { return version_str; } /** * The module initialisation routine, called when the module * is first loaded. */ void ModuleInit() { MXS_NOTICE("Initialise the MySQL Monitor module %s.", version_str); } /** * The module entry point routine. It is this routine that * must populate the structure that is referred to as the * "module object", this is a structure with the set of * external entry points for this module. * * @return The module object */ MONITOR_OBJECT * GetModuleObject() { return &MyObject; } /** * Start the instance of the monitor, returning a handle on the monitor. * * This function creates a thread to execute the actual monitoring. * * @param arg The current handle - NULL if first start * @param opt Configuration parameters * @return A handle to use when interacting with the monitor */ static void * startMonitor(void *arg, void* opt) { MONITOR* monitor = (MONITOR*) arg; MYSQL_MONITOR *handle = (MYSQL_MONITOR*) monitor->handle; CONFIG_PARAMETER* params = (CONFIG_PARAMETER*) opt; bool have_events = false, script_error = false; if (handle) { handle->shutdown = 0; } else { if ((handle = (MYSQL_MONITOR *) malloc(sizeof(MYSQL_MONITOR))) == NULL) return NULL; handle->shutdown = 0; handle->id = config_get_gateway_id(); handle->replicationHeartbeat = 0; handle->detectStaleMaster = 0; handle->master = NULL; handle->script = NULL; handle->mysql51_replication = false; memset(handle->events, false, sizeof(handle->events)); spinlock_init(&handle->lock); } while (params) { if (!strcmp(params->name, "detect_stale_master")) handle->detectStaleMaster = config_truth_value(params->value); else if (!strcmp(params->name, "detect_replication_lag")) handle->replicationHeartbeat = config_truth_value(params->value); else if (!strcmp(params->name, "script")) { if (externcmd_can_execute(params->value)) { free(handle->script); handle->script = strdup(params->value); } else { script_error = true; } } else if (!strcmp(params->name, "events")) { if (mon_parse_event_string((bool*) & handle->events, sizeof(handle->events), params->value) != 0) script_error = true; else have_events = true; } else if (!strcmp(params->name, "mysql51_replication")) { handle->mysql51_replication = config_truth_value(params->value); } params = params->next; } if (script_error) { MXS_ERROR("Errors were found in the script configuration parameters " "for the monitor '%s'. The script will not be used.", monitor->name); free(handle->script); handle->script = NULL; } /** If no specific events are given, enable them all */ if (!have_events) { memset(handle->events, true, sizeof(handle->events)); } if (thread_start(&handle->thread, monitorMain, monitor) == NULL) { MXS_ERROR("Failed to start monitor thread for monitor '%s'.", monitor->name); } return handle; } /** * Stop a running monitor * * @param arg Handle on thr running monior */ static void stopMonitor(void *arg) { MONITOR* mon = (MONITOR*) arg; MYSQL_MONITOR *handle = (MYSQL_MONITOR *) mon->handle; handle->shutdown = 1; thread_wait(handle->thread); } /** * Daignostic interface * * @param dcb DCB to print diagnostics * @param arg The monitor handle */ static void diagnostics(DCB *dcb, void *arg) { MONITOR* mon = (MONITOR*) arg; MYSQL_MONITOR *handle = (MYSQL_MONITOR *) mon->handle; MONITOR_SERVERS *db; char *sep; switch (handle->status) { case MONITOR_RUNNING: dcb_printf(dcb, "\tMonitor running\n"); break; case MONITOR_STOPPING: dcb_printf(dcb, "\tMonitor stopping\n"); break; case MONITOR_STOPPED: dcb_printf(dcb, "\tMonitor stopped\n"); break; } dcb_printf(dcb, "\tSampling interval:\t%lu milliseconds\n", mon->interval); dcb_printf(dcb, "\tMaxScale MonitorId:\t%lu\n", handle->id); dcb_printf(dcb, "\tReplication lag:\t%s\n", (handle->replicationHeartbeat == 1) ? "enabled" : "disabled"); dcb_printf(dcb, "\tDetect Stale Master:\t%s\n", (handle->detectStaleMaster == 1) ? "enabled" : "disabled"); dcb_printf(dcb, "\tConnect Timeout:\t%i seconds\n", mon->connect_timeout); dcb_printf(dcb, "\tRead Timeout:\t\t%i seconds\n", mon->read_timeout); dcb_printf(dcb, "\tWrite Timeout:\t\t%i seconds\n", mon->write_timeout); dcb_printf(dcb, "\tMonitored servers: "); db = mon->databases; sep = ""; while (db) { dcb_printf(dcb, "%s%s:%d", sep, db->server->name, db->server->port); sep = ", "; db = db->next; } dcb_printf(dcb, "\n"); } static inline void monitor_mysql100_db(MONITOR_SERVERS* database) { int isslave = 0; MYSQL_RES* result; MYSQL_ROW row; if (mysql_query(database->con, "SHOW ALL SLAVES STATUS") == 0 && (result = mysql_store_result(database->con)) != NULL) { int i = 0; long master_id = -1; if (mysql_field_count(database->con) < 42) { mysql_free_result(result); MXS_ERROR("\"SHOW ALL SLAVES STATUS\" " "returned less than the expected amount of columns. Expected 42 columns." " MySQL Version: %s", version_str); return; } while ((row = mysql_fetch_row(result))) { /* get Slave_IO_Running and Slave_SQL_Running values*/ if (strncmp(row[12], "Yes", 3) == 0 && strncmp(row[13], "Yes", 3) == 0) { isslave += 1; } /* If Slave_IO_Running = Yes, assign the master_id to current server: this allows building * the replication tree, slaves ids will be added to master(s) and we will have at least the * root master server. * Please note, there could be no slaves at all if Slave_SQL_Running == 'No' */ if (strncmp(row[12], "Yes", 3) == 0) { /* get Master_Server_Id values */ master_id = atol(row[41]); if (master_id == 0) master_id = -1; } i++; } /* store master_id of current node */ memcpy(&database->server->master_id, &master_id, sizeof(long)); mysql_free_result(result); /* If all configured slaves are running set this node as slave */ if (isslave > 0 && isslave == i) { isslave = 1; } else { isslave = 0; } } /* Remove addition info */ monitor_clear_pending_status(database, SERVER_SLAVE_OF_EXTERNAL_MASTER); monitor_clear_pending_status(database, SERVER_STALE_STATUS); /* Please note, the MASTER status and SERVER_SLAVE_OF_EXTERNAL_MASTER * will be assigned in the monitorMain() via get_replication_tree() routine */ /* Set the Slave Role */ if (isslave) { monitor_set_pending_status(database, SERVER_SLAVE); /* Avoid any possible stale Master state */ monitor_clear_pending_status(database, SERVER_MASTER); } else { /* Avoid any possible Master/Slave stale state */ monitor_clear_pending_status(database, SERVER_SLAVE); monitor_clear_pending_status(database, SERVER_MASTER); } } static inline void monitor_mysql55_db(MONITOR_SERVERS* database) { bool isslave = false; MYSQL_RES* result; MYSQL_ROW row; if (mysql_query(database->con, "SHOW SLAVE STATUS") == 0 && (result = mysql_store_result(database->con)) != NULL) { long master_id = -1; if (mysql_field_count(database->con) < 40) { mysql_free_result(result); MXS_ERROR("\"SHOW SLAVE STATUS\" " "returned less than the expected amount of columns. Expected 40 columns." " MySQL Version: %s", version_str); return; } while ((row = mysql_fetch_row(result))) { /* get Slave_IO_Running and Slave_SQL_Running values*/ if (strncmp(row[10], "Yes", 3) == 0 && strncmp(row[11], "Yes", 3) == 0) { isslave = 1; } /* If Slave_IO_Running = Yes, assign the master_id to current server: this allows building * the replication tree, slaves ids will be added to master(s) and we will have at least the * root master server. * Please note, there could be no slaves at all if Slave_SQL_Running == 'No' */ if (strncmp(row[10], "Yes", 3) == 0) { /* get Master_Server_Id values */ master_id = atol(row[39]); if (master_id == 0) master_id = -1; } } /* store master_id of current node */ memcpy(&database->server->master_id, &master_id, sizeof(long)); mysql_free_result(result); } /* Remove addition info */ monitor_clear_pending_status(database, SERVER_SLAVE_OF_EXTERNAL_MASTER); monitor_clear_pending_status(database, SERVER_STALE_STATUS); /* Please note, the MASTER status and SERVER_SLAVE_OF_EXTERNAL_MASTER * will be assigned in the monitorMain() via get_replication_tree() routine */ /* Set the Slave Role */ if (isslave) { monitor_set_pending_status(database, SERVER_SLAVE); /* Avoid any possible stale Master state */ monitor_clear_pending_status(database, SERVER_MASTER); } else { /* Avoid any possible Master/Slave stale state */ monitor_clear_pending_status(database, SERVER_SLAVE); monitor_clear_pending_status(database, SERVER_MASTER); } } static inline void monitor_mysql51_db(MONITOR_SERVERS* database) { bool isslave = false; MYSQL_RES* result; MYSQL_ROW row; if (mysql_query(database->con, "SHOW SLAVE STATUS") == 0 && (result = mysql_store_result(database->con)) != NULL) { if (mysql_field_count(database->con) < 38) { mysql_free_result(result); MXS_ERROR("\"SHOW SLAVE STATUS\" " "returned less than the expected amount of columns. Expected 38 columns." " MySQL Version: %s", version_str); return; } while ((row = mysql_fetch_row(result))) { /* get Slave_IO_Running and Slave_SQL_Running values*/ if (strncmp(row[10], "Yes", 3) == 0 && strncmp(row[11], "Yes", 3) == 0) { isslave = 1; } } mysql_free_result(result); } /* Remove addition info */ monitor_clear_pending_status(database, SERVER_SLAVE_OF_EXTERNAL_MASTER); monitor_clear_pending_status(database, SERVER_STALE_STATUS); /* Please note, the MASTER status and SERVER_SLAVE_OF_EXTERNAL_MASTER * will be assigned in the monitorMain() via get_replication_tree() routine */ /* Set the Slave Role */ if (isslave) { monitor_set_pending_status(database, SERVER_SLAVE); /* Avoid any possible stale Master state */ monitor_clear_pending_status(database, SERVER_MASTER); } else { /* Avoid any possible Master/Slave stale state */ monitor_clear_pending_status(database, SERVER_SLAVE); monitor_clear_pending_status(database, SERVER_MASTER); } } /** * Build the replication tree for a MySQL 5.1 cluster * * This function queries each server with SHOW SLAVE HOSTS to determine which servers * have slaves replicating from them. * @param mon Monitor * @return Lowest server ID master in the monitor */ static MONITOR_SERVERS *build_mysql51_replication_tree(MONITOR *mon) { MONITOR_SERVERS* database = mon->databases; MONITOR_SERVERS *ptr, *rval = NULL; int i; while (database) { bool ismaster = false; MYSQL_RES* result; MYSQL_ROW row; int nslaves = 0; if (database->con) { if (mysql_query(database->con, "SHOW SLAVE HOSTS") == 0 && (result = mysql_store_result(database->con)) != NULL) { if (mysql_field_count(database->con) < 4) { mysql_free_result(result); MXS_ERROR("\"SHOW SLAVE HOSTS\" " "returned less than the expected amount of columns. " "Expected 4 columns." " MySQL Version: %s", version_str); return NULL; } if (mysql_num_rows(result) > 0) { ismaster = true; while (nslaves < MONITOR_MAX_NUM_SLAVES && (row = mysql_fetch_row(result))) { /* get Slave_IO_Running and Slave_SQL_Running values*/ database->server->slaves[nslaves] = atol(row[0]); nslaves++; MXS_DEBUG("Found slave at %s:%s", row[1], row[2]); } database->server->slaves[nslaves] = 0; } mysql_free_result(result); } /* Set the Slave Role */ if (ismaster) { MXS_DEBUG("Master server found at %s:%d with %d slaves", database->server->name, database->server->port, nslaves); monitor_set_pending_status(database, SERVER_MASTER); if (rval == NULL || rval->server->node_id > database->server->node_id) rval = database; } } database = database->next; } database = mon->databases; /** Set master server IDs */ while (database) { ptr = mon->databases; while (ptr) { for (i = 0; ptr->server->slaves[i]; i++) { if (ptr->server->slaves[i] == database->server->node_id) { database->server->master_id = ptr->server->node_id; break; } } ptr = ptr->next; } if (database->server->master_id <= 0 && SERVER_IS_SLAVE(database->server)) { monitor_set_pending_status(database, SERVER_SLAVE_OF_EXTERNAL_MASTER); } database = database->next; } return rval; } /** * Monitor an individual server * * @param handle The MySQL Monitor object * @param database The database to probe */ static void monitorDatabase(MONITOR *mon, MONITOR_SERVERS *database) { MYSQL_MONITOR* handle = mon->handle; MYSQL_ROW row; MYSQL_RES *result; int isslave = 0; char *uname = mon->user; unsigned long int server_version = 0; char *server_string; if (database->server->monuser != NULL) { uname = database->server->monuser; } if (uname == NULL) return; /* Don't probe servers in maintenance mode */ if (SERVER_IN_MAINT(database->server)) return; /** Store previous status */ database->mon_prev_status = database->server->status; if (database->con == NULL || mysql_ping(database->con) != 0) { connect_result_t rval; if ((rval = mon_connect_to_db(mon, database)) == MONITOR_CONN_OK) { server_clear_status(database->server, SERVER_AUTH_ERROR); monitor_clear_pending_status(database, SERVER_AUTH_ERROR); } else { /* The current server is not running * * Store server NOT running in server and monitor server pending struct * */ if (mysql_errno(database->con) == ER_ACCESS_DENIED_ERROR) { server_set_status(database->server, SERVER_AUTH_ERROR); monitor_set_pending_status(database, SERVER_AUTH_ERROR); } server_clear_status(database->server, SERVER_RUNNING); monitor_clear_pending_status(database, SERVER_RUNNING); /* Also clear M/S state in both server and monitor server pending struct */ server_clear_status(database->server, SERVER_SLAVE); server_clear_status(database->server, SERVER_MASTER); monitor_clear_pending_status(database, SERVER_SLAVE); monitor_clear_pending_status(database, SERVER_MASTER); /* Clean addition status too */ server_clear_status(database->server, SERVER_SLAVE_OF_EXTERNAL_MASTER); server_clear_status(database->server, SERVER_STALE_STATUS); monitor_clear_pending_status(database, SERVER_SLAVE_OF_EXTERNAL_MASTER); monitor_clear_pending_status(database, SERVER_STALE_STATUS); /* Log connect failure only once */ if (mon_status_changed(database) && mon_print_fail_status(database)) { mon_log_connect_error(database, rval); } return; } } /* Store current status in both server and monitor server pending struct */ server_set_status(database->server, SERVER_RUNNING); monitor_set_pending_status(database, SERVER_RUNNING); /* get server version from current server */ server_version = mysql_get_server_version(database->con); /* get server version string */ server_string = (char *) mysql_get_server_info(database->con); if (server_string) { server_set_version_string(database->server, server_string); } /* get server_id form current node */ if (mysql_query(database->con, "SELECT @@server_id") == 0 && (result = mysql_store_result(database->con)) != NULL) { long server_id = -1; if (mysql_field_count(database->con) != 1) { mysql_free_result(result); MXS_ERROR("Unexpected result for 'SELECT @@server_id'. Expected 1 column." " MySQL Version: %s", version_str); return; } while ((row = mysql_fetch_row(result))) { server_id = strtol(row[0], NULL, 10); if ((errno == ERANGE && (server_id == LONG_MAX || server_id == LONG_MIN)) || (errno != 0 && server_id == 0)) { server_id = -1; } database->server->node_id = server_id; } mysql_free_result(result); } /* Check first for MariaDB 10.x.x and get status for multi-master replication */ if (server_version >= 100000) { monitor_mysql100_db(database); } else if (server_version >= 5 * 10000 + 5 * 100) { monitor_mysql55_db(database); } else { if (handle->mysql51_replication) { monitor_mysql51_db(database); } else if (report_version_err) { report_version_err = false; MXS_ERROR("MySQL version is lower than 5.5 and 'mysql51_replication' option is " "not enabled," " replication tree cannot be resolved. To enable MySQL 5.1 replication " "detection, " "add 'mysql51_replication=true' to the monitor section."); } } } /** * The entry point for the monitoring module thread * * @param arg The handle of the monitor */ static void monitorMain(void *arg) { MONITOR* mon = (MONITOR*) arg; MYSQL_MONITOR *handle; MONITOR_SERVERS *ptr; int replication_heartbeat; int detect_stale_master; int num_servers = 0; MONITOR_SERVERS *root_master = NULL; size_t nrounds = 0; int log_no_master = 1; bool heartbeat_checked = false; spinlock_acquire(&mon->lock); handle = (MYSQL_MONITOR *) mon->handle; spinlock_release(&mon->lock); replication_heartbeat = handle->replicationHeartbeat; detect_stale_master = handle->detectStaleMaster; if (mysql_thread_init()) { MXS_ERROR("mysql_thread_init failed in monitor module. Exiting."); return; } handle->status = MONITOR_RUNNING; while (1) { if (handle->shutdown) { handle->status = MONITOR_STOPPING; mysql_thread_end(); handle->status = MONITOR_STOPPED; return; } /** Wait base interval */ thread_millisleep(MON_BASE_INTERVAL_MS); if (handle->replicationHeartbeat && !heartbeat_checked) { check_maxscale_schema_replication(mon); heartbeat_checked = true; } /** * Calculate how far away the monitor interval is from its full * cycle and if monitor interval time further than the base * interval, then skip monitoring checks. Excluding the first * round. */ if (nrounds != 0 && ((nrounds * MON_BASE_INTERVAL_MS) % mon->interval) >= MON_BASE_INTERVAL_MS) { nrounds += 1; continue; } nrounds += 1; /* reset num_servers */ num_servers = 0; /* start from the first server in the list */ ptr = mon->databases; while (ptr) { ptr->mon_prev_status = ptr->server->status; /* copy server status into monitor pending_status */ ptr->pending_status = ptr->server->status; /* monitor current node */ monitorDatabase(mon, ptr); /* reset the slave list of current node */ if (ptr->server->slaves) { free(ptr->server->slaves); } /* create a new slave list */ ptr->server->slaves = (long *) calloc(MONITOR_MAX_NUM_SLAVES, sizeof(long)); num_servers++; if (mon_status_changed(ptr)) { if (SRV_MASTER_STATUS(ptr->mon_prev_status)) { /** Master failed, can't recover */ MXS_NOTICE("Server %s:%d lost the master status.", ptr->server->name, ptr->server->port); } /** * Here we say: If the server's state changed * so that it isn't running or some other way * lost cluster membership, call call-back function * of every DCB for which such callback was * registered for this kind of issue (DCB_REASON_...) */ if (!(SERVER_IS_RUNNING(ptr->server)) || !(SERVER_IS_IN_CLUSTER(ptr->server))) { dcb_hangup_foreach(ptr->server); } } if (mon_status_changed(ptr)) { #if defined(SS_DEBUG) MXS_INFO("Backend server %s:%d state : %s", ptr->server->name, ptr->server->port, STRSRVSTATUS(ptr->server)); #else MXS_DEBUG("Backend server %s:%d state : %s", ptr->server->name, ptr->server->port, STRSRVSTATUS(ptr->server)); #endif } if (SERVER_IS_DOWN(ptr->server)) { /** Increase this server'e error count */ ptr->mon_err_count += 1; } else { /** Reset this server's error count */ ptr->mon_err_count = 0; } ptr = ptr->next; } ptr = mon->databases; /* if only one server is configured, that's is Master */ if (num_servers == 1) { if (SERVER_IS_RUNNING(ptr->server)) { ptr->server->depth = 0; /* status cleanup */ monitor_clear_pending_status(ptr, SERVER_SLAVE); /* master status set */ monitor_set_pending_status(ptr, SERVER_MASTER); ptr->server->depth = 0; handle->master = ptr; root_master = ptr; } } else { /* Compute the replication tree */ if (handle->mysql51_replication) root_master = build_mysql51_replication_tree(mon); else root_master = get_replication_tree(mon, num_servers); } /* Update server status from monitor pending status on that server*/ ptr = mon->databases; while (ptr) { if (!SERVER_IN_MAINT(ptr->server)) { /* If "detect_stale_master" option is On, let's use the previus master */ if (detect_stale_master && root_master && (!strcmp(ptr->server->name, root_master->server->name) && ptr->server->port == root_master->server->port) && (ptr->server->status & SERVER_MASTER) && !(ptr->pending_status & SERVER_MASTER)) { /** * In this case server->status will not be updated from pending_statu * Set the STALE bit for this server in server struct */ server_set_status(ptr->server, SERVER_STALE_STATUS); /* log it once */ if (mon_status_changed(ptr)) { MXS_WARNING("[mysql_mon]: root server " "[%s:%i] is no longer Master," " let's use it again even " " if it could be a stale master," " you have been warned!", ptr->server->name, ptr->server->port); } } else { ptr->server->status = ptr->pending_status; } } ptr = ptr->next; } ptr = mon->databases; monitor_event_t evtype; while (ptr) { /** Execute monitor script if a server state has changed */ if (mon_status_changed(ptr)) { evtype = mon_get_event_type(ptr); if (isMySQLEvent(evtype)) { MXS_NOTICE("Server changed state: %s[%s:%u]: %s", ptr->server->unique_name, ptr->server->name, ptr->server->port, mon_get_event_name(ptr)); if (handle->script && handle->events[evtype]) { monitor_launch_script(mon, ptr, handle->script); } } } ptr = ptr->next; } /* log master detection failure of first master becomes available after failure */ if (root_master && mon_status_changed(root_master) && !(root_master->server->status & SERVER_STALE_STATUS)) { if (root_master->pending_status & (SERVER_MASTER) && SERVER_IS_RUNNING(root_master->server)) { if (!(root_master->mon_prev_status & SERVER_STALE_STATUS) && !(root_master->server->status & SERVER_MAINT)) { MXS_NOTICE("A Master Server is now available: %s:%i", root_master->server->name, root_master->server->port); } } else { MXS_ERROR("No Master can be determined. Last known was %s:%i", root_master->server->name, root_master->server->port); } log_no_master = 1; } else { if (!root_master && log_no_master) { MXS_ERROR("No Master can be determined"); log_no_master = 0; } } /* Do now the heartbeat replication set/get for MySQL Replication Consistency */ if (replication_heartbeat && root_master && (SERVER_IS_MASTER(root_master->server) || SERVER_IS_RELAY_SERVER(root_master->server))) { set_master_heartbeat(handle, root_master); ptr = mon->databases; while (ptr) { if ((!SERVER_IN_MAINT(ptr->server)) && SERVER_IS_RUNNING(ptr->server)) { if (ptr->server->node_id != root_master->server->node_id && (SERVER_IS_SLAVE(ptr->server) || SERVER_IS_RELAY_SERVER(ptr->server))) { set_slave_heartbeat(mon, ptr); } } ptr = ptr->next; } } } /*< while (1) */ } /** * Set the default id to use in the monitor. * * @param arg The handle allocated by startMonitor * @param id The id to set in monitor struct */ static void defaultId(void *arg, unsigned long id) { MYSQL_MONITOR *handle = (MYSQL_MONITOR *) arg; memcpy(&handle->id, &id, sizeof(unsigned long)); } /** * Enable/Disable the MySQL Replication hearbeat, detecting slave lag behind master. * * @param arg The handle allocated by startMonitor * @param enable To enable it 1, disable it with 0 */ static void replicationHeartbeat(void *arg, int enable) { MYSQL_MONITOR *handle = (MYSQL_MONITOR *) arg; memcpy(&handle->replicationHeartbeat, &enable, sizeof(int)); } /** * Enable/Disable the MySQL Replication Stale Master dectection, allowing a previouvsly detected master to still act as a Master. * This option must be enabled in order to keep the Master when the replication is stopped or removed from slaves. * If the replication is still stopped when MaxSclale is restarted no Master will be available. * * @param arg The handle allocated by startMonitor * @param enable To enable it 1, disable it with 0 */ static void detectStaleMaster(void *arg, int enable) { MYSQL_MONITOR *handle = (MYSQL_MONITOR *) arg; memcpy(&handle->detectStaleMaster, &enable, sizeof(int)); } /** * Fetch a MySQL node by node_id * * @param ptr The list of servers to monitor * @param node_id The MySQL server_id to fetch * @return The server with the required server_id */ static MONITOR_SERVERS * getServerByNodeId(MONITOR_SERVERS *ptr, long node_id) { SERVER *current; while (ptr) { current = ptr->server; if (current->node_id == node_id) { return ptr; } ptr = ptr->next; } return NULL; } /** * Fetch a MySQL slave node from a node_id * * @param ptr The list of servers to monitor * @param node_id The MySQL server_id to fetch * @return The slave server of this node_id */ static MONITOR_SERVERS * getSlaveOfNodeId(MONITOR_SERVERS *ptr, long node_id) { SERVER *current; while (ptr) { current = ptr->server; if (current->master_id == node_id) { return ptr; } ptr = ptr->next; } return NULL; } /******* * This function sets the replication heartbeat * into the maxscale_schema.replication_heartbeat table in the current master. * The inserted values will be seen from all slaves replication from this master. * * @param handle The monitor handle * @param database The number database server */ static void set_master_heartbeat(MYSQL_MONITOR *handle, MONITOR_SERVERS *database) { unsigned long id = handle->id; time_t heartbeat; time_t purge_time; char heartbeat_insert_query[512] = ""; char heartbeat_purge_query[512] = ""; if (handle->master == NULL) { MXS_ERROR("[mysql_mon]: set_master_heartbeat called without an available Master server"); return; } /* create the maxscale_schema database */ if (mysql_query(database->con, "CREATE DATABASE IF NOT EXISTS maxscale_schema")) { MXS_ERROR("[mysql_mon]: Error creating maxscale_schema database in Master server" ": %s", mysql_error(database->con)); database->server->rlag = -1; } /* create repl_heartbeat table in maxscale_schema database */ if (mysql_query(database->con, "CREATE TABLE IF NOT EXISTS " "maxscale_schema.replication_heartbeat " "(maxscale_id INT NOT NULL, " "master_server_id INT NOT NULL, " "master_timestamp INT UNSIGNED NOT NULL, " "PRIMARY KEY ( master_server_id, maxscale_id ) ) " "ENGINE=MYISAM DEFAULT CHARSET=latin1")) { MXS_ERROR("[mysql_mon]: Error creating maxscale_schema.replication_heartbeat " "table in Master server: %s", mysql_error(database->con)); database->server->rlag = -1; } /* auto purge old values after 48 hours*/ purge_time = time(0) - (3600 * 48); sprintf(heartbeat_purge_query, "DELETE FROM maxscale_schema.replication_heartbeat WHERE master_timestamp < %lu", purge_time); if (mysql_query(database->con, heartbeat_purge_query)) { MXS_ERROR("[mysql_mon]: Error deleting from maxscale_schema.replication_heartbeat " "table: [%s], %s", heartbeat_purge_query, mysql_error(database->con)); } heartbeat = time(0); /* set node_ts for master as time(0) */ database->server->node_ts = heartbeat; sprintf(heartbeat_insert_query, "UPDATE maxscale_schema.replication_heartbeat SET master_timestamp = %lu WHERE master_server_id = %li AND maxscale_id = %lu", heartbeat, handle->master->server->node_id, id); /* Try to insert MaxScale timestamp into master */ if (mysql_query(database->con, heartbeat_insert_query)) { database->server->rlag = -1; MXS_ERROR("[mysql_mon]: Error updating maxscale_schema.replication_heartbeat table: [%s], %s", heartbeat_insert_query, mysql_error(database->con)); } else { if (mysql_affected_rows(database->con) == 0) { heartbeat = time(0); sprintf(heartbeat_insert_query, "REPLACE INTO maxscale_schema.replication_heartbeat (master_server_id, maxscale_id, master_timestamp ) VALUES ( %li, %lu, %lu)", handle->master->server->node_id, id, heartbeat); if (mysql_query(database->con, heartbeat_insert_query)) { database->server->rlag = -1; MXS_ERROR("[mysql_mon]: Error inserting into " "maxscale_schema.replication_heartbeat table: [%s], %s", heartbeat_insert_query, mysql_error(database->con)); } else { /* Set replication lag to 0 for the master */ database->server->rlag = 0; MXS_DEBUG("[mysql_mon]: heartbeat table inserted data for %s:%i", database->server->name, database->server->port); } } else { /* Set replication lag as 0 for the master */ database->server->rlag = 0; MXS_DEBUG("[mysql_mon]: heartbeat table updated for Master %s:%i", database->server->name, database->server->port); } } } /******* * This function gets the replication heartbeat * from the maxscale_schema.replication_heartbeat table in the current slave * and stores the timestamp and replication lag in the slave server struct * * @param handle The monitor handle * @param database The number database server */ static void set_slave_heartbeat(MONITOR* mon, MONITOR_SERVERS *database) { MYSQL_MONITOR *handle = (MYSQL_MONITOR*) mon->handle; unsigned long id = handle->id; time_t heartbeat; char select_heartbeat_query[256] = ""; MYSQL_ROW row; MYSQL_RES *result; if (handle->master == NULL) { MXS_ERROR("[mysql_mon]: set_slave_heartbeat called without an available Master server"); return; } /* Get the master_timestamp value from maxscale_schema.replication_heartbeat table */ sprintf(select_heartbeat_query, "SELECT master_timestamp " "FROM maxscale_schema.replication_heartbeat " "WHERE maxscale_id = %lu AND master_server_id = %li", id, handle->master->server->node_id); /* if there is a master then send the query to the slave with master_id */ if (handle->master != NULL && (mysql_query(database->con, select_heartbeat_query) == 0 && (result = mysql_store_result(database->con)) != NULL)) { int rows_found = 0; while ((row = mysql_fetch_row(result))) { int rlag = -1; time_t slave_read; rows_found = 1; heartbeat = time(0); slave_read = strtoul(row[0], NULL, 10); if ((errno == ERANGE && (slave_read == LONG_MAX || slave_read == LONG_MIN)) || (errno != 0 && slave_read == 0)) { slave_read = 0; } if (slave_read) { /* set the replication lag */ rlag = heartbeat - slave_read; } /* set this node_ts as master_timestamp read from replication_heartbeat table */ database->server->node_ts = slave_read; if (rlag >= 0) { /* store rlag only if greater than monitor sampling interval */ database->server->rlag = (rlag > (mon->interval / 1000)) ? rlag : 0; } else { database->server->rlag = -1; } MXS_DEBUG("Slave %s:%i has %i seconds lag", database->server->name, database->server->port, database->server->rlag); } if (!rows_found) { database->server->rlag = -1; database->server->node_ts = 0; } mysql_free_result(result); } else { database->server->rlag = -1; database->server->node_ts = 0; if (handle->master->server->node_id < 0) { MXS_ERROR("[mysql_mon]: error: replication heartbeat: " "master_server_id NOT available for %s:%i", database->server->name, database->server->port); } else { MXS_ERROR("[mysql_mon]: error: replication heartbeat: " "failed selecting from hearthbeat table of %s:%i : [%s], %s", database->server->name, database->server->port, select_heartbeat_query, mysql_error(database->con)); } } } /******* * This function computes the replication tree * from a set of MySQL Master/Slave monitored servers * and returns the root server with SERVER_MASTER bit. * The tree is computed even for servers in 'maintenance' mode. * * @param handle The monitor handle * @param num_servers The number of servers monitored * @return The server at root level with SERVER_MASTER bit */ static MONITOR_SERVERS *get_replication_tree(MONITOR *mon, int num_servers) { MYSQL_MONITOR* handle = (MYSQL_MONITOR*) mon->handle; MONITOR_SERVERS *ptr; MONITOR_SERVERS *backend; SERVER *current; int depth = 0; long node_id; int root_level; ptr = mon->databases; root_level = num_servers; while (ptr) { /* The server could be in SERVER_IN_MAINT * that means SERVER_IS_RUNNING returns 0 * Let's check only for SERVER_IS_DOWN: server is not running */ if (SERVER_IS_DOWN(ptr->server)) { ptr = ptr->next; continue; } depth = 0; current = ptr->server; node_id = current->master_id; if (node_id < 1) { MONITOR_SERVERS *find_slave; find_slave = getSlaveOfNodeId(mon->databases, current->node_id); if (find_slave == NULL) { current->depth = -1; ptr = ptr->next; continue; } else { current->depth = 0; } } else { depth++; } while (depth <= num_servers) { /* set the root master at lowest depth level */ if (current->depth > -1 && current->depth < root_level) { root_level = current->depth; handle->master = ptr; } backend = getServerByNodeId(mon->databases, node_id); if (backend) { node_id = backend->server->master_id; } else { node_id = -1; } if (node_id > 0) { current->depth = depth + 1; depth++; } else { MONITOR_SERVERS *master; current->depth = depth; master = getServerByNodeId(mon->databases, current->master_id); if (master && master->server && master->server->node_id > 0) { add_slave_to_master(master->server->slaves, MONITOR_MAX_NUM_SLAVES, current->node_id); master->server->depth = current->depth - 1; monitor_set_pending_status(master, SERVER_MASTER); handle->master = master; } else { if (current->master_id > 0) { /* this server is slave of another server not in MaxScale configuration * we cannot use it as a real slave. */ monitor_clear_pending_status(ptr, SERVER_SLAVE); monitor_set_pending_status(ptr, SERVER_SLAVE_OF_EXTERNAL_MASTER); } } break; } } ptr = ptr->next; } /* * Return the root master */ if (handle->master != NULL) { /* If the root master is in MAINT, return NULL */ if (SERVER_IN_MAINT(handle->master->server)) { return NULL; } else { return handle->master; } } else { return NULL; } } /******* * This function add a slave id into the slaves server field * of its master server * * @param slaves_list The slave list array of the master server * @param list_size The size of the slave list * @param node_id The node_id of the slave to be inserted * @return 1 for inserted value and 0 otherwise */ static int add_slave_to_master(long *slaves_list, int list_size, long node_id) { for (int i = 0; i < list_size; i++) { if (slaves_list[i] == 0) { memcpy(&slaves_list[i], &node_id, sizeof(long)); return 1; } } return 0; } static monitor_event_t mysql_events[] = { MASTER_DOWN_EVENT, MASTER_UP_EVENT, SLAVE_DOWN_EVENT, SLAVE_UP_EVENT, SERVER_DOWN_EVENT, SERVER_UP_EVENT, LOST_MASTER_EVENT, LOST_SLAVE_EVENT, NEW_MASTER_EVENT, NEW_SLAVE_EVENT, MAX_MONITOR_EVENT }; /** * Check if the MySQL monitor is monitoring this event type. * @param event Event to check * @return True if the event is monitored, false if it is not * */ bool isMySQLEvent(monitor_event_t event) { int i; for (i = 0; mysql_events[i] != MAX_MONITOR_EVENT; i++) { if (event == mysql_events[i]) return true; } return false; } /** * Check if replicate_ignore_table is defined and if maxscale_schema.replication_hearbeat * table is in the list. * @param database Server to check * @return False if the table is not replicated or an error occurred when querying * the server */ bool check_replicate_ignore_table(MONITOR_SERVERS* database) { MYSQL_RES *result; bool rval = true; if (mysql_query(database->con, "show variables like 'replicate_ignore_table'") == 0 && (result = mysql_store_result(database->con)) && mysql_num_fields(result) > 1) { MYSQL_ROW row; while ((row = mysql_fetch_row(result))) { if (strlen(row[1]) > 0 && strcasestr(row[1], hb_table_name)) { MXS_WARNING("'replicate_ignore_table' is " "defined on server '%s' and '%s' was found in it. ", database->server->unique_name, hb_table_name); rval = false; } } mysql_free_result(result); } else { MXS_ERROR("Failed to query server %s for " "'replicate_ignore_table': %s", database->server->unique_name, mysql_error(database->con)); rval = false; } return rval; } /** * Check if replicate_do_table is defined and if maxscale_schema.replication_hearbeat * table is not in the list. * @param database Server to check * @return False if the table is not replicated or an error occurred when querying * the server */ bool check_replicate_do_table(MONITOR_SERVERS* database) { MYSQL_RES *result; bool rval = true; if (mysql_query(database->con, "show variables like 'replicate_do_table'") == 0 && (result = mysql_store_result(database->con)) && mysql_num_fields(result) > 1) { MYSQL_ROW row; while ((row = mysql_fetch_row(result))) { if (strlen(row[1]) > 0 && strcasestr(row[1], hb_table_name) == NULL) { MXS_WARNING("'replicate_do_table' is " "defined on server '%s' and '%s' was not found in it. ", database->server->unique_name, hb_table_name); rval = false; } } mysql_free_result(result); } else { MXS_ERROR("Failed to query server %s for " "'replicate_do_table': %s", database->server->unique_name, mysql_error(database->con)); rval = false; } return rval; } /** * Check if replicate_wild_do_table is defined and if it doesn't match * maxscale_schema.replication_heartbeat. * @param database Database server * @return False if the table is not replicated or an error occurred when trying to * query the server. */ bool check_replicate_wild_do_table(MONITOR_SERVERS* database) { MYSQL_RES *result; bool rval = true; if (mysql_query(database->con, "show variables like 'replicate_wild_do_table'") == 0 && (result = mysql_store_result(database->con)) && mysql_num_fields(result) > 1) { MYSQL_ROW row; while ((row = mysql_fetch_row(result))) { if (strlen(row[1]) > 0) { mxs_pcre2_result_t rc = modutil_mysql_wildcard_match(row[1], hb_table_name); if (rc == MXS_PCRE2_NOMATCH) { MXS_WARNING("'replicate_wild_do_table' is " "defined on server '%s' and '%s' does not match it. ", database->server->unique_name, hb_table_name); rval = false; } } } mysql_free_result(result); } else { MXS_ERROR("Failed to query server %s for " "'replicate_wild_do_table': %s", database->server->unique_name, mysql_error(database->con)); rval = false; } return rval; } /** * Check if replicate_wild_ignore_table is defined and if it matches * maxscale_schema.replication_heartbeat. * @param database Database server * @return False if the table is not replicated or an error occurred when trying to * query the server. */ bool check_replicate_wild_ignore_table(MONITOR_SERVERS* database) { MYSQL_RES *result; bool rval = true; if (mysql_query(database->con, "show variables like 'replicate_wild_ignore_table'") == 0 && (result = mysql_store_result(database->con)) && mysql_num_fields(result) > 1) { MYSQL_ROW row; while ((row = mysql_fetch_row(result))) { if (strlen(row[1]) > 0) { mxs_pcre2_result_t rc = modutil_mysql_wildcard_match(row[1], hb_table_name); if (rc == MXS_PCRE2_MATCH) { MXS_WARNING("'replicate_wild_ignore_table' is " "defined on server '%s' and '%s' matches it. ", database->server->unique_name, hb_table_name); rval = false; } } } mysql_free_result(result); } else { MXS_ERROR("Failed to query server %s for " "'replicate_wild_do_table': %s", database->server->unique_name, mysql_error(database->con)); rval = false; } return rval; } /** * Check if the maxscale_schema.replication_heartbeat table is replicated on all * servers and log a warning if problems were found. * @param monitor Monitor structure */ void check_maxscale_schema_replication(MONITOR *monitor) { MONITOR_SERVERS* database = monitor->databases; bool err = false; while (database) { connect_result_t rval = mon_connect_to_db(monitor, database); if (rval == MONITOR_CONN_OK) { if (!check_replicate_ignore_table(database) || !check_replicate_do_table(database) || !check_replicate_wild_do_table(database) || !check_replicate_wild_ignore_table(database)) { err = true; } } else { mon_log_connect_error(database, rval); } database = database->next; } if (err) { MXS_WARNING("Problems were encountered when " "checking if '%s' is replicated. Make sure that the table is " "replicated to all slaves.", hb_table_name); } }