/* * Copyright (c) 2016 MariaDB Corporation Ab * * Use of this software is governed by the Business Source License included * in the LICENSE.TXT file and at www.mariadb.com/bsl11. * * Change Date: 2022-01-01 * * On the date above, in accordance with the Business Source License, use * of this software will be governed by version 2 or later of the General * Public License. */ /** * @file monitor.c - The monitor module management routines */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internal/config.hh" #include "internal/externcmd.h" #include "internal/monitor.hh" #include "internal/modules.h" /** Schema version, journals must have a matching version */ #define MMB_SCHEMA_VERSION 2 /** Constants for byte lengths of the values */ #define MMB_LEN_BYTES 4 #define MMB_LEN_SCHEMA_VERSION 1 #define MMB_LEN_CRC32 4 #define MMB_LEN_VALUE_TYPE 1 #define MMB_LEN_SERVER_STATUS 8 /** Type of the stored value */ enum stored_value_type { SVT_SERVER = 1, // Generic server state information SVT_MASTER = 2, // The master server name }; using std::string; using std::set; const char CN_BACKEND_CONNECT_ATTEMPTS[] = "backend_connect_attempts"; const char CN_BACKEND_CONNECT_TIMEOUT[] = "backend_connect_timeout"; const char CN_BACKEND_READ_TIMEOUT[] = "backend_read_timeout"; const char CN_BACKEND_WRITE_TIMEOUT[] = "backend_write_timeout"; const char CN_DISK_SPACE_CHECK_INTERVAL[] = "disk_space_check_interval"; const char CN_EVENTS[] = "events"; const char CN_JOURNAL_MAX_AGE[] = "journal_max_age"; const char CN_MONITOR_INTERVAL[] = "monitor_interval"; const char CN_SCRIPT[] = "script"; const char CN_SCRIPT_TIMEOUT[] = "script_timeout"; static MXS_MONITOR* allMonitors = NULL; static std::mutex monLock; static void monitor_server_free_all(MXS_MONITORED_SERVER* servers); static void remove_server_journal(MXS_MONITOR* monitor); static bool journal_is_stale(MXS_MONITOR* monitor, time_t max_age); static const char* monitor_state_to_string(monitor_state_t state); /** Server type specific bits */ static uint64_t server_type_bits = SERVER_MASTER | SERVER_SLAVE | SERVER_JOINED | SERVER_NDB; /** All server bits */ static uint64_t all_server_bits = SERVER_RUNNING | SERVER_MAINT | SERVER_MASTER | SERVER_SLAVE | SERVER_JOINED | SERVER_NDB; /** * Create a new monitor, load the associated module for the monitor * and start execution on the monitor. * * @param name The name of the monitor module to load * @param module The module to load * @return The newly created monitor */ MXS_MONITOR* monitor_create(const char* name, const char* module, MXS_CONFIG_PARAMETER* params) { MXS_MONITOR_API* api = (MXS_MONITOR_API*)load_module(module, MODULE_MONITOR); if (api == NULL) { MXS_ERROR("Unable to load monitor module '%s'.", name); return NULL; } char* my_name = MXS_STRDUP(name); char* my_module = MXS_STRDUP(module); MXS_MONITOR* mon = (MXS_MONITOR*)MXS_MALLOC(sizeof(MXS_MONITOR)); if (!mon || !my_module || !my_name) { MXS_FREE(mon); MXS_FREE(my_name); MXS_FREE(my_module); return NULL; } mon->api = api; mon->active = true; mon->state = MONITOR_STATE_STOPPED; mon->name = my_name; mon->module_name = my_module; mon->monitored_servers = NULL; mon->read_timeout = config_get_integer(params, CN_BACKEND_READ_TIMEOUT); mon->write_timeout = config_get_integer(params, CN_BACKEND_WRITE_TIMEOUT); mon->connect_timeout = config_get_integer(params, CN_BACKEND_CONNECT_TIMEOUT); mon->connect_attempts = config_get_integer(params, CN_BACKEND_CONNECT_ATTEMPTS); mon->interval = config_get_integer(params, CN_MONITOR_INTERVAL); mon->journal_max_age = config_get_integer(params, CN_JOURNAL_MAX_AGE); mon->script_timeout = config_get_integer(params, CN_SCRIPT_TIMEOUT); mon->script = config_get_string(params, CN_SCRIPT); mon->events = config_get_enum(params, CN_EVENTS, mxs_monitor_event_enum_values); mon->check_maintenance_flag = MAINTENANCE_FLAG_NOCHECK; mon->ticks = 0; mon->parameters = NULL; memset(mon->journal_hash, 0, sizeof(mon->journal_hash)); mon->disk_space_threshold = NULL; mon->disk_space_check_interval = config_get_integer(params, CN_DISK_SPACE_CHECK_INTERVAL); pthread_mutex_init(&mon->lock, NULL); for (auto& s : mxs::strtok(config_get_string(params, CN_SERVERS), ",")) { fix_object_name(s); monitor_add_server(mon, server_find_by_unique_name(s.c_str())); } monitor_add_user(mon, config_get_string(params, CN_USER), config_get_string(params, CN_PASSWORD)); /* The previous config values were normal types and were checked before this function * to be correct. The following is a complicated type and needs to be checked now. */ bool error = false; const char* threshold_string = config_get_string(params, CN_DISK_SPACE_THRESHOLD); if (!monitor_set_disk_space_threshold(mon, threshold_string)) { MXS_ERROR("Invalid value for '%s' for monitor %s: %s", CN_DISK_SPACE_THRESHOLD, mon->name, threshold_string); error = true; } if (!error) { // Store module, used when the monitor is serialized monitor_set_parameter(mon, CN_MODULE, module); monitor_add_parameters(mon, params); if ((mon->instance = mon->api->createInstance(mon)) == NULL) { MXS_ERROR("Unable to create monitor instance for '%s', using module '%s'.", name, module); error = true; } } if (!error) { std::lock_guard guard(monLock); mon->next = allMonitors; allMonitors = mon; } else { MXS_FREE(mon); mon = NULL; MXS_FREE(my_module); MXS_FREE(my_name); } return mon; } /** * Free a monitor, first stop the monitor and then remove the monitor from * the chain of monitors and free the memory. * * @param mon The monitor to free */ void monitor_destroy(MXS_MONITOR* mon) { MXS_MONITOR* ptr; std::unique_lock guard(monLock); if (allMonitors == mon) { allMonitors = mon->next; } else { ptr = allMonitors; while (ptr->next && ptr->next != mon) { ptr = ptr->next; } if (ptr->next) { ptr->next = mon->next; } } guard.unlock(); mon->api->destroyInstance(mon->instance); delete mon->disk_space_threshold; config_parameter_free(mon->parameters); monitor_server_free_all(mon->monitored_servers); MXS_FREE(mon->name); MXS_FREE(mon->module_name); MXS_FREE(mon); } void monitor_destroy_all() { // monitor_destroy() grabs 'monLock', so it cannot be grabbed here // without additional changes. But this function should only be // called at system shutdown in single-thread context. while (allMonitors) { MXS_MONITOR* monitor = allMonitors; monitor_destroy(monitor); } } /** * Start an individual monitor that has previously been stopped. * * @param monitor The Monitor that should be started */ void monitor_start(MXS_MONITOR* monitor, const MXS_CONFIG_PARAMETER* params) { if (monitor) { pthread_mutex_lock(&monitor->lock); // Only start the monitor if it's stopped. if (monitor->state == MONITOR_STATE_STOPPED) { if (journal_is_stale(monitor, monitor->journal_max_age)) { MXS_WARNING("Removing stale journal file for monitor '%s'.", monitor->name); remove_server_journal(monitor); } if ((*monitor->api->startMonitor)(monitor->instance, params)) { monitor->state = MONITOR_STATE_RUNNING; } else { MXS_ERROR("Failed to start monitor '%s'.", monitor->name); } } pthread_mutex_unlock(&monitor->lock); } } /** * Start all monitors */ void monitor_start_all() { MXS_MONITOR* ptr; std::lock_guard guard(monLock); ptr = allMonitors; while (ptr) { if (ptr->active) { monitor_start(ptr, ptr->parameters); } ptr = ptr->next; } } /** * Stop a given monitor * * @param monitor The monitor to stop */ void monitor_stop(MXS_MONITOR* monitor) { if (monitor) { pthread_mutex_lock(&monitor->lock); /** Only stop the monitor if it is running */ if (monitor->state == MONITOR_STATE_RUNNING) { monitor->state = MONITOR_STATE_STOPPING; monitor->api->stopMonitor(monitor->instance); monitor->state = MONITOR_STATE_STOPPED; MXS_MONITORED_SERVER* db = monitor->monitored_servers; while (db) { // TODO: Create a generic entry point for this or move it inside stopMonitor mysql_close(db->con); db->con = NULL; db = db->next; } } pthread_mutex_unlock(&monitor->lock); } } void monitor_deactivate(MXS_MONITOR* monitor) { std::lock_guard guard(monLock); monitor->active = false; } /** * Shutdown all running monitors */ void monitor_stop_all() { std::lock_guard guard(monLock); for (MXS_MONITOR* monitor = allMonitors; monitor; monitor = monitor->next) { if (monitor->active) { monitor_stop(monitor); } } } /** * Add a server to a monitor. Simply register the server that needs to be * monitored to the running monitor module. * * @param mon The Monitor instance * @param server The Server to add to the monitoring */ bool monitor_add_server(MXS_MONITOR* mon, SERVER* server) { mxb_assert(mon && server); bool rval = false; if (monitor_server_in_use(server)) { MXS_ERROR("Server '%s' is already monitored.", server->name); } else { rval = true; MXS_MONITORED_SERVER* db = (MXS_MONITORED_SERVER*)MXS_MALLOC(sizeof(MXS_MONITORED_SERVER)); MXS_ABORT_IF_NULL(db); db->server = server; db->con = NULL; db->next = NULL; db->mon_err_count = 0; db->log_version_err = true; // Pretend disk space was just checked. db->disk_space_checked = maxscale::MonitorInstance::get_time_ms(); /** Server status is uninitialized */ db->mon_prev_status = -1; /* pending status is updated by get_replication_tree */ db->pending_status = 0; monitor_state_t old_state = mon->state; if (old_state == MONITOR_STATE_RUNNING) { monitor_stop(mon); } pthread_mutex_lock(&mon->lock); if (mon->monitored_servers == NULL) { mon->monitored_servers = db; } else { MXS_MONITORED_SERVER* ptr = mon->monitored_servers; while (ptr->next != NULL) { ptr = ptr->next; } ptr->next = db; } pthread_mutex_unlock(&mon->lock); if (old_state == MONITOR_STATE_RUNNING) { monitor_start(mon, mon->parameters); } } return rval; } static void monitor_server_free(MXS_MONITORED_SERVER* tofree) { if (tofree) { if (tofree->con) { mysql_close(tofree->con); } MXS_FREE(tofree); } } /** * Free monitor server list * @param servers Servers to free */ static void monitor_server_free_all(MXS_MONITORED_SERVER* servers) { while (servers) { MXS_MONITORED_SERVER* tofree = servers; servers = servers->next; monitor_server_free(tofree); } } /** * Remove a server from a monitor. * * @param mon The Monitor instance * @param server The Server to remove */ void monitor_remove_server(MXS_MONITOR* mon, SERVER* server) { monitor_state_t old_state = mon->state; if (old_state == MONITOR_STATE_RUNNING) { monitor_stop(mon); } pthread_mutex_lock(&mon->lock); MXS_MONITORED_SERVER* ptr = mon->monitored_servers; if (ptr && ptr->server == server) { mon->monitored_servers = mon->monitored_servers->next; } else { MXS_MONITORED_SERVER* prev = ptr; while (ptr) { if (ptr->server == server) { prev->next = ptr->next; break; } prev = ptr; ptr = ptr->next; } } pthread_mutex_unlock(&mon->lock); if (ptr) { monitor_server_free(ptr); } if (old_state == MONITOR_STATE_RUNNING) { monitor_start(mon, mon->parameters); } } /** * Add a default user to the monitor. This user is used to connect to the * monitored databases but may be overriden on a per server basis. * * @param mon The monitor instance * @param user The default username to use when connecting * @param passwd The default password associated to the default user. */ void monitor_add_user(MXS_MONITOR* mon, const char* user, const char* passwd) { if (user != mon->user) { snprintf(mon->user, sizeof(mon->user), "%s", user); } if (passwd != mon->password) { snprintf(mon->password, sizeof(mon->password), "%s", passwd); } } /** * Show all monitors * * @param dcb DCB for printing output */ void monitor_show_all(DCB* dcb) { std::lock_guard guard(monLock); for (MXS_MONITOR* ptr = allMonitors; ptr; ptr = ptr->next) { if (ptr->active) { monitor_show(dcb, ptr); } } } /** * Show a single monitor * * @param dcb DCB for printing output */ void monitor_show(DCB* dcb, MXS_MONITOR* monitor) { dcb_printf(dcb, "Monitor: %p\n", monitor); dcb_printf(dcb, "Name: %s\n", monitor->name); dcb_printf(dcb, "State: %s\n", monitor_state_to_string(monitor->state)); dcb_printf(dcb, "Times monitored: %lu\n", monitor->ticks); dcb_printf(dcb, "Sampling interval: %lu milliseconds\n", monitor->interval); dcb_printf(dcb, "Connect Timeout: %i seconds\n", monitor->connect_timeout); dcb_printf(dcb, "Read Timeout: %i seconds\n", monitor->read_timeout); dcb_printf(dcb, "Write Timeout: %i seconds\n", monitor->write_timeout); dcb_printf(dcb, "Connect attempts: %i \n", monitor->connect_attempts); dcb_printf(dcb, "Monitored servers: "); const char* sep = ""; for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { dcb_printf(dcb, "%s[%s]:%d", sep, db->server->address, db->server->port); sep = ", "; } dcb_printf(dcb, "\n"); if (monitor->instance) { if (monitor->api->diagnostics && monitor->state == MONITOR_STATE_RUNNING) { monitor->api->diagnostics(monitor->instance, dcb); } else { dcb_printf(dcb, " (no diagnostics)\n"); } } else { dcb_printf(dcb, " Monitor failed\n"); } dcb_printf(dcb, "\n"); } /** * List all the monitors * * @param dcb DCB for printing output */ void monitor_list(DCB* dcb) { MXS_MONITOR* ptr; std::lock_guard guard(monLock); ptr = allMonitors; dcb_printf(dcb, "---------------------+---------------------\n"); dcb_printf(dcb, "%-20s | Status\n", "Monitor"); dcb_printf(dcb, "---------------------+---------------------\n"); while (ptr) { if (ptr->active) { dcb_printf(dcb, "%-20s | %s\n", ptr->name, ptr->state == MONITOR_STATE_RUNNING ? "Running" : "Stopped"); } ptr = ptr->next; } dcb_printf(dcb, "---------------------+---------------------\n"); } /** * Find a monitor by name * * @param name The name of the monitor * @return Pointer to the monitor or NULL */ MXS_MONITOR* monitor_find(const char* name) { std::lock_guard guard(monLock); for (MXS_MONITOR* ptr = allMonitors; ptr; ptr = ptr->next) { if (!strcmp(ptr->name, name) && ptr->active) { return ptr; } } return nullptr; } /** * Find a destroyed monitor by name * * @param name The name of the monitor * @return Pointer to the destroyed monitor or NULL if monitor is not found */ MXS_MONITOR* monitor_repurpose_destroyed(const char* name, const char* module) { MXS_MONITOR* rval = NULL; std::lock_guard guard(monLock); for (MXS_MONITOR* ptr = allMonitors; ptr; ptr = ptr->next) { if (strcmp(ptr->name, name) == 0 && strcmp(ptr->module_name, module) == 0) { mxb_assert(!ptr->active); ptr->active = true; rval = ptr; } } return rval; } /** * Set the monitor sampling interval. * * @param mon The monitor instance * @param interval The sampling interval in milliseconds */ void monitor_set_interval(MXS_MONITOR* mon, unsigned long interval) { mon->interval = interval; } /** * Set the maximum age of the monitor journal * * @param mon The monitor instance * @param interval The journal age in seconds */ void monitor_set_journal_max_age(MXS_MONITOR* mon, time_t value) { mon->journal_max_age = value; } void monitor_set_script_timeout(MXS_MONITOR* mon, uint32_t value) { mon->script_timeout = value; } /** * Set Monitor timeouts for connect/read/write * * @param mon The monitor instance * @param type The timeout handling type * @param value The timeout to set */ bool monitor_set_network_timeout(MXS_MONITOR* mon, int type, int value, const char* key) { bool rval = true; if (value > 0) { switch (type) { case MONITOR_CONNECT_TIMEOUT: mon->connect_timeout = value; break; case MONITOR_READ_TIMEOUT: mon->read_timeout = value; break; case MONITOR_WRITE_TIMEOUT: mon->write_timeout = value; break; case MONITOR_CONNECT_ATTEMPTS: mon->connect_attempts = value; break; default: MXS_ERROR("Monitor setNetworkTimeout received an unsupported action type %i", type); mxb_assert(!true); rval = false; break; } } else { MXS_ERROR("Value '%s' for monitor '%s' is not a positive integer: %d", key, mon->name, value); rval = false; } return rval; } /** * Return a resultset that has the current set of monitors in it * * @return A Result set */ std::unique_ptr monitor_get_list() { std::unique_ptr set = ResultSet::create({"Monitor", "Status"}); std::lock_guard guard(monLock); for (MXS_MONITOR* ptr = allMonitors; ptr; ptr = ptr->next) { const char* state = ptr->state & MONITOR_STATE_RUNNING ? "Running" : "Stopped"; set->add_row({ptr->name, state}); } return set; } /** * @brief Check if the monitor user has all required permissions to operate properly. * * @param service Monitor to inspect * @param query Query to execute * @return True on success, false if monitor credentials lack permissions */ bool check_monitor_permissions(MXS_MONITOR* monitor, const char* query) { if (monitor->monitored_servers == NULL // No servers to check || config_get_global_options()->skip_permission_checks) { return true; } char* user = monitor->user; char* dpasswd = decrypt_password(monitor->password); MXS_CONFIG* cnf = config_get_global_options(); bool rval = false; for (MXS_MONITORED_SERVER* mondb = monitor->monitored_servers; mondb; mondb = mondb->next) { if (!mon_connection_is_ok(mon_ping_or_connect_to_db(monitor, mondb))) { MXS_ERROR("[%s] Failed to connect to server '%s' ([%s]:%d) when" " checking monitor user credentials and permissions: %s", monitor->name, mondb->server->name, mondb->server->address, mondb->server->port, mysql_error(mondb->con)); switch (mysql_errno(mondb->con)) { case ER_ACCESS_DENIED_ERROR: case ER_DBACCESS_DENIED_ERROR: case ER_ACCESS_DENIED_NO_PASSWORD_ERROR: break; default: rval = true; break; } } else if (mxs_mysql_query(mondb->con, query) != 0) { switch (mysql_errno(mondb->con)) { case ER_TABLEACCESS_DENIED_ERROR: case ER_COLUMNACCESS_DENIED_ERROR: case ER_SPECIFIC_ACCESS_DENIED_ERROR: case ER_PROCACCESS_DENIED_ERROR: case ER_KILL_DENIED_ERROR: rval = false; break; default: rval = true; break; } MXS_ERROR("[%s] Failed to execute query '%s' with user '%s'. MySQL error message: %s", monitor->name, query, user, mysql_error(mondb->con)); } else { rval = true; MYSQL_RES* res = mysql_use_result(mondb->con); if (res == NULL) { MXS_ERROR("[%s] Result retrieval failed when checking monitor permissions: %s", monitor->name, mysql_error(mondb->con)); } else { mysql_free_result(res); } } } MXS_FREE(dpasswd); return rval; } /** * Add parameters to the monitor * @param monitor Monitor * @param params Config parameters */ void monitor_add_parameters(MXS_MONITOR* monitor, MXS_CONFIG_PARAMETER* params) { pthread_mutex_lock(&monitor->lock); while (params) { MXS_CONFIG_PARAMETER* old = config_get_param(monitor->parameters, params->name); if (old) { MXS_FREE(old->value); old->value = MXS_STRDUP_A(params->value); } else { MXS_CONFIG_PARAMETER* clone = config_clone_param(params); clone->next = monitor->parameters; monitor->parameters = clone; } params = params->next; } pthread_mutex_unlock(&monitor->lock); } void monitor_set_parameter(MXS_MONITOR* monitor, const char* key, const char* value) { monitor_remove_parameter(monitor, key); MXS_CONFIG_PARAMETER p = {}; p.name = const_cast(key); p.value = const_cast(value); monitor_add_parameters(monitor, &p); } bool monitor_remove_parameter(MXS_MONITOR* monitor, const char* key) { MXS_CONFIG_PARAMETER* prev = NULL; bool rval = false; pthread_mutex_lock(&monitor->lock); for (MXS_CONFIG_PARAMETER* p = monitor->parameters; p; p = p->next) { if (strcmp(p->name, key) == 0) { if (p == monitor->parameters) { monitor->parameters = monitor->parameters->next; } else { prev->next = p->next; } p->next = NULL; config_parameter_free(p); rval = true; break; } prev = p; } pthread_mutex_unlock(&monitor->lock); return rval; } void mon_alter_parameter(MXS_MONITOR* monitor, const char* key, const char* value) { pthread_mutex_lock(&monitor->lock); for (MXS_CONFIG_PARAMETER* p = monitor->parameters; p; p = p->next) { if (strcmp(p->name, key) == 0) { MXS_FREE(p->value); p->value = MXS_STRDUP_A(value); break; } } pthread_mutex_unlock(&monitor->lock); } /** * Set pending status bits in the monitor server * * @param server The server to update * @param bit The bits to set for the server */ void monitor_set_pending_status(MXS_MONITORED_SERVER* ptr, uint64_t bit) { ptr->pending_status |= bit; } /** * Clear pending status bits in the monitor server * * @param server The server to update * @param bit The bits to clear for the server */ void monitor_clear_pending_status(MXS_MONITORED_SERVER* ptr, uint64_t bit) { ptr->pending_status &= ~bit; } /* * Determine a monitor event, defined by the difference between the old * status of a server and the new status. * * @param node The monitor server data for a particular server * @result monitor_event_t A monitor event (enum) * * @note This function must only be called from mon_process_state_changes */ static mxs_monitor_event_t mon_get_event_type(MXS_MONITORED_SERVER* node) { typedef enum { DOWN_EVENT, UP_EVENT, LOSS_EVENT, NEW_EVENT, UNSUPPORTED_EVENT } general_event_type; general_event_type event_type = UNSUPPORTED_EVENT; uint64_t prev = node->mon_prev_status & all_server_bits; uint64_t present = node->server->status & all_server_bits; if (prev == present) { /* This should never happen */ mxb_assert(false); return UNDEFINED_EVENT; } if ((prev & SERVER_RUNNING) == 0) { /* The server was not running previously */ if ((present & SERVER_RUNNING) != 0) { event_type = UP_EVENT; } else { /* Otherwise, was not running and still is not running. This should never happen. */ mxb_assert(false); } } else { /* Previous state must have been running */ if ((present & SERVER_RUNNING) == 0) { event_type = DOWN_EVENT; } else { /** These are used to detect whether we actually lost something or * just transitioned from one state to another */ uint64_t prev_bits = prev & (SERVER_MASTER | SERVER_SLAVE); uint64_t present_bits = present & (SERVER_MASTER | SERVER_SLAVE); /* Was running and still is */ if ((!prev_bits || !present_bits || prev_bits == present_bits) && (prev & server_type_bits)) { /* We used to know what kind of server it was */ event_type = LOSS_EVENT; } else { /* We didn't know what kind of server it was, now we do*/ event_type = NEW_EVENT; } } } mxs_monitor_event_t rval = UNDEFINED_EVENT; switch (event_type) { case UP_EVENT: rval = (present & SERVER_MASTER) ? MASTER_UP_EVENT : (present & SERVER_SLAVE) ? SLAVE_UP_EVENT : (present & SERVER_JOINED) ? SYNCED_UP_EVENT : (present & SERVER_NDB) ? NDB_UP_EVENT : SERVER_UP_EVENT; break; case DOWN_EVENT: rval = (prev & SERVER_MASTER) ? MASTER_DOWN_EVENT : (prev & SERVER_SLAVE) ? SLAVE_DOWN_EVENT : (prev & SERVER_JOINED) ? SYNCED_DOWN_EVENT : (prev & SERVER_NDB) ? NDB_DOWN_EVENT : SERVER_DOWN_EVENT; break; case LOSS_EVENT: rval = (prev & SERVER_MASTER) ? LOST_MASTER_EVENT : (prev & SERVER_SLAVE) ? LOST_SLAVE_EVENT : (prev & SERVER_JOINED) ? LOST_SYNCED_EVENT : (prev & SERVER_NDB) ? LOST_NDB_EVENT : UNDEFINED_EVENT; break; case NEW_EVENT: rval = (present & SERVER_MASTER) ? NEW_MASTER_EVENT : (present & SERVER_SLAVE) ? NEW_SLAVE_EVENT : (present & SERVER_JOINED) ? NEW_SYNCED_EVENT : (present & SERVER_NDB) ? NEW_NDB_EVENT : UNDEFINED_EVENT; break; default: /* This should never happen */ mxb_assert(false); break; } mxb_assert(rval != UNDEFINED_EVENT); return rval; } const char* mon_get_event_name(mxs_monitor_event_t event) { for (int i = 0; mxs_monitor_event_enum_values[i].name; i++) { if (mxs_monitor_event_enum_values[i].enum_value == event) { return mxs_monitor_event_enum_values[i].name; } } mxb_assert(!true); return "undefined_event"; } /* * Given a monitor event (enum) provide a text string equivalent * @param node The monitor server data whose event is wanted * @result string The name of the monitor event for the server */ static const char* mon_get_event_name(MXS_MONITORED_SERVER* node) { return mon_get_event_name((mxs_monitor_event_t)node->server->last_event); } enum credentials_approach_t { CREDENTIALS_INCLUDE, CREDENTIALS_EXCLUDE, }; /** * Create a list of running servers * * @param mon The monitor * @param dest Destination where the string is appended, must be null terminated * @param len Length of @c dest * @param approach Whether credentials should be included or not. */ static void mon_append_node_names(MXS_MONITOR* mon, char* dest, int len, int status, credentials_approach_t approach = CREDENTIALS_EXCLUDE) { MXS_MONITORED_SERVER* servers = mon->monitored_servers; const char* separator = ""; char arr[MAX_SERVER_MONUSER_LEN + MAX_SERVER_MONPW_LEN + MAX_SERVER_ADDRESS_LEN + 64]; // Some extra space for port and separator dest[0] = '\0'; while (servers && len) { if (status == 0 || servers->server->status & status) { if (approach == CREDENTIALS_EXCLUDE) { snprintf(arr, sizeof(arr), "%s[%s]:%d", separator, servers->server->address, servers->server->port); } else { const char* user; const char* password; if (*servers->server->monuser) { user = servers->server->monuser; password = servers->server->monpw; } else { user = mon->user; password = mon->password; } snprintf(arr, sizeof(arr), "%s%s:%s@[%s]:%d", separator, user, password, servers->server->address, servers->server->port); } separator = ","; int arrlen = strlen(arr); if (arrlen < len) { strcat(dest, arr); len -= arrlen; } } servers = servers->next; } } /** * Check if current monitored server status has changed * * @param mon_srv The monitored server * @return true if status has changed or false */ bool mon_status_changed(MXS_MONITORED_SERVER* mon_srv) { bool rval = false; /* Previous status is -1 if not yet set */ if (mon_srv->mon_prev_status != static_cast(-1)) { uint64_t old_status = mon_srv->mon_prev_status & all_server_bits; uint64_t new_status = mon_srv->server->status & all_server_bits; /** * The state has changed if the relevant state bits are not the same, * the server is either running, stopping or starting and the server is * not going into maintenance or coming out of it */ if (old_status != new_status && ((old_status | new_status) & SERVER_MAINT) == 0 && ((old_status | new_status) & SERVER_RUNNING) == SERVER_RUNNING) { rval = true; } } return rval; } /** * Check if current monitored server has a loggable failure status * * @param mon_srv The monitored server * @return true if failed status can be logged or false */ bool mon_print_fail_status(MXS_MONITORED_SERVER* mon_srv) { return server_is_down(mon_srv->server) && mon_srv->mon_err_count == 0; } static MXS_MONITORED_SERVER* find_parent_node(MXS_MONITORED_SERVER* servers, MXS_MONITORED_SERVER* target) { MXS_MONITORED_SERVER* rval = NULL; if (target->server->master_id > 0) { for (MXS_MONITORED_SERVER* node = servers; node; node = node->next) { if (node->server->node_id == target->server->master_id) { rval = node; break; } } } return rval; } static std::string child_nodes(MXS_MONITORED_SERVER* servers, MXS_MONITORED_SERVER* parent) { std::stringstream ss; if (parent->server->node_id > 0) { bool have_content = false; for (MXS_MONITORED_SERVER* node = servers; node; node = node->next) { if (node->server->master_id == parent->server->node_id) { if (have_content) { ss << ","; } ss << "[" << node->server->address << "]:" << node->server->port; have_content = true; } } } return ss.str(); } int monitor_launch_command(MXS_MONITOR* mon, MXS_MONITORED_SERVER* ptr, EXTERNCMD* cmd) { if (externcmd_matches(cmd, "$INITIATOR")) { char initiator[strlen(ptr->server->address) + 24]; // Extra space for port snprintf(initiator, sizeof(initiator), "[%s]:%d", ptr->server->address, ptr->server->port); externcmd_substitute_arg(cmd, "[$]INITIATOR", initiator); } if (externcmd_matches(cmd, "$PARENT")) { std::stringstream ss; MXS_MONITORED_SERVER* parent = find_parent_node(mon->monitored_servers, ptr); if (parent) { ss << "[" << parent->server->address << "]:" << parent->server->port; } externcmd_substitute_arg(cmd, "[$]PARENT", ss.str().c_str()); } if (externcmd_matches(cmd, "$CHILDREN")) { externcmd_substitute_arg(cmd, "[$]CHILDREN", child_nodes(mon->monitored_servers, ptr).c_str()); } if (externcmd_matches(cmd, "$EVENT")) { externcmd_substitute_arg(cmd, "[$]EVENT", mon_get_event_name(ptr)); } char nodelist[PATH_MAX + MON_ARG_MAX + 1] = {'\0'}; if (externcmd_matches(cmd, "$CREDENTIALS")) { // We provide the credentials for _all_ servers. mon_append_node_names(mon, nodelist, sizeof(nodelist), 0, CREDENTIALS_INCLUDE); externcmd_substitute_arg(cmd, "[$]CREDENTIALS", nodelist); } if (externcmd_matches(cmd, "$NODELIST")) { mon_append_node_names(mon, nodelist, sizeof(nodelist), SERVER_RUNNING); externcmd_substitute_arg(cmd, "[$]NODELIST", nodelist); } if (externcmd_matches(cmd, "$LIST")) { mon_append_node_names(mon, nodelist, sizeof(nodelist), 0); externcmd_substitute_arg(cmd, "[$]LIST", nodelist); } if (externcmd_matches(cmd, "$MASTERLIST")) { mon_append_node_names(mon, nodelist, sizeof(nodelist), SERVER_MASTER); externcmd_substitute_arg(cmd, "[$]MASTERLIST", nodelist); } if (externcmd_matches(cmd, "$SLAVELIST")) { mon_append_node_names(mon, nodelist, sizeof(nodelist), SERVER_SLAVE); externcmd_substitute_arg(cmd, "[$]SLAVELIST", nodelist); } if (externcmd_matches(cmd, "$SYNCEDLIST")) { mon_append_node_names(mon, nodelist, sizeof(nodelist), SERVER_JOINED); externcmd_substitute_arg(cmd, "[$]SYNCEDLIST", nodelist); } int rv = externcmd_execute(cmd); if (rv) { if (rv == -1) { // Internal error MXS_ERROR("Failed to execute script '%s' on server state change event '%s'", cmd->argv[0], mon_get_event_name(ptr)); } else { // Script returned a non-zero value MXS_ERROR("Script '%s' returned %d on event '%s'", cmd->argv[0], rv, mon_get_event_name(ptr)); } } else { mxb_assert(cmd->argv != NULL && cmd->argv[0] != NULL); // Construct a string with the script + arguments char* scriptStr = NULL; int totalStrLen = 0; bool memError = false; for (int i = 0; cmd->argv[i]; i++) { totalStrLen += strlen(cmd->argv[i]) + 1; // +1 for space and one \0 } int spaceRemaining = totalStrLen; if ((scriptStr = (char*)MXS_CALLOC(totalStrLen, sizeof(char))) != NULL) { char* currentPos = scriptStr; // The script name should not begin with a space int len = snprintf(currentPos, spaceRemaining, "%s", cmd->argv[0]); currentPos += len; spaceRemaining -= len; for (int i = 1; cmd->argv[i]; i++) { if ((cmd->argv[i])[0] == '\0') { continue; // Empty argument, print nothing } len = snprintf(currentPos, spaceRemaining, " %s", cmd->argv[i]); currentPos += len; spaceRemaining -= len; } mxb_assert(spaceRemaining > 0); *currentPos = '\0'; } else { memError = true; scriptStr = cmd->argv[0]; // print at least something } MXS_NOTICE("Executed monitor script '%s' on event '%s'", scriptStr, mon_get_event_name(ptr)); if (!memError) { MXS_FREE(scriptStr); } } return rv; } int monitor_launch_script(MXS_MONITOR* mon, MXS_MONITORED_SERVER* ptr, const char* script, uint32_t timeout) { char arg[strlen(script) + 1]; strcpy(arg, script); EXTERNCMD* cmd = externcmd_allocate(arg, timeout); if (cmd == NULL) { MXS_ERROR("Failed to initialize script '%s'. See previous errors for the " "cause of this failure.", script); return -1; } int rv = monitor_launch_command(mon, ptr, cmd); externcmd_free(cmd); return rv; } /** * Ping or connect to a database. If connection does not exist or ping fails, a new connection is created. * This will always leave a valid database handle in the database->con pointer, allowing the user to call * MySQL C API functions to find out the reason of the failure. * * @param mon Monitor * @param database Monitored database * @return Connection status. */ mxs_connect_result_t mon_ping_or_connect_to_db(MXS_MONITOR* mon, MXS_MONITORED_SERVER* database) { if (database->con) { /** Return if the connection is OK */ if (mysql_ping(database->con) == 0) { return MONITOR_CONN_EXISTING_OK; } /** Otherwise close the handle. */ mysql_close(database->con); } mxs_connect_result_t conn_result = MONITOR_CONN_REFUSED; if ((database->con = mysql_init(NULL))) { char* uname = mon->user; char* passwd = mon->password; if (database->server->monuser[0] && database->server->monpw[0]) { uname = database->server->monuser; passwd = database->server->monpw; } char* dpwd = decrypt_password(passwd); mysql_optionsv(database->con, MYSQL_OPT_CONNECT_TIMEOUT, (void*) &mon->connect_timeout); mysql_optionsv(database->con, MYSQL_OPT_READ_TIMEOUT, (void*) &mon->read_timeout); mysql_optionsv(database->con, MYSQL_OPT_WRITE_TIMEOUT, (void*) &mon->write_timeout); mysql_optionsv(database->con, MYSQL_PLUGIN_DIR, get_connector_plugindir()); time_t start = 0; time_t end = 0; for (int i = 0; i < mon->connect_attempts; i++) { start = time(NULL); bool result = (mxs_mysql_real_connect(database->con, database->server, uname, dpwd) != NULL); end = time(NULL); if (result) { conn_result = MONITOR_CONN_NEWCONN_OK; break; } } if (conn_result == MONITOR_CONN_REFUSED && (int)difftime(end, start) >= mon->connect_timeout) { conn_result = MONITOR_CONN_TIMEOUT; } MXS_FREE(dpwd); } return conn_result; } /** * Is the return value one of the 'OK' values. * * @param connect_result Return value of mon_ping_or_connect_to_db * @return True of connection is ok */ bool mon_connection_is_ok(mxs_connect_result_t connect_result) { return connect_result == MONITOR_CONN_EXISTING_OK || connect_result == MONITOR_CONN_NEWCONN_OK; } /** * Log an error about the failure to connect to a backend server and why it happened. * * @param database Backend database * @param rval Return value of mon_ping_or_connect_to_db */ void mon_log_connect_error(MXS_MONITORED_SERVER* database, mxs_connect_result_t rval) { mxb_assert(!mon_connection_is_ok(rval) && database); const char TIMED_OUT[] = "Monitor timed out when connecting to server %s[%s:%d] : '%s'"; const char REFUSED[] = "Monitor was unable to connect to server %s[%s:%d] : '%s'"; auto srv = database->server; MXS_ERROR(rval == MONITOR_CONN_TIMEOUT ? TIMED_OUT : REFUSED, srv->name, srv->address, srv->port, mysql_error(database->con)); } static void mon_log_state_change(MXS_MONITORED_SERVER* ptr) { SERVER srv; srv.status = ptr->mon_prev_status; char* prev = server_status(&srv); char* next = server_status(ptr->server); MXS_NOTICE("Server changed state: %s[%s:%u]: %s. [%s] -> [%s]", ptr->server->name, ptr->server->address, ptr->server->port, mon_get_event_name(ptr), prev, next); MXS_FREE(prev); MXS_FREE(next); } MXS_MONITOR* monitor_server_in_use(const SERVER* server) { MXS_MONITOR* rval = NULL; std::lock_guard guard(monLock); for (MXS_MONITOR* mon = allMonitors; mon && !rval; mon = mon->next) { pthread_mutex_lock(&mon->lock); if (mon->active) { for (MXS_MONITORED_SERVER* db = mon->monitored_servers; db && !rval; db = db->next) { if (db->server == server) { rval = mon; } } } pthread_mutex_unlock(&mon->lock); } return rval; } static bool create_monitor_config(const MXS_MONITOR* monitor, const char* filename) { int file = open(filename, O_EXCL | O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); if (file == -1) { MXS_ERROR("Failed to open file '%s' when serializing monitor '%s': %d, %s", filename, monitor->name, errno, mxs_strerror(errno)); return false; } pthread_mutex_lock((pthread_mutex_t*)&monitor->lock); dprintf(file, "[%s]\n", monitor->name); dprintf(file, "%s=monitor\n", CN_TYPE); if (monitor->monitored_servers) { dprintf(file, "%s=", CN_SERVERS); for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { if (db != monitor->monitored_servers) { dprintf(file, ","); } dprintf(file, "%s", db->server->name); } dprintf(file, "\n"); } const MXS_MODULE* mod = get_module(monitor->module_name, NULL); mxb_assert(mod); dump_param_list(file, monitor->parameters, {CN_TYPE, CN_SERVERS}, config_monitor_params, mod->parameters); pthread_mutex_unlock((pthread_mutex_t*)&monitor->lock); close(file); return true; } bool monitor_serialize(const MXS_MONITOR* monitor) { bool rval = false; char filename[PATH_MAX]; snprintf(filename, sizeof(filename), "%s/%s.cnf.tmp", get_config_persistdir(), monitor->name); if (unlink(filename) == -1 && errno != ENOENT) { MXS_ERROR("Failed to remove temporary monitor configuration at '%s': %d, %s", filename, errno, mxs_strerror(errno)); } else if (create_monitor_config(monitor, filename)) { char final_filename[PATH_MAX]; strcpy(final_filename, filename); char* dot = strrchr(final_filename, '.'); mxb_assert(dot); *dot = '\0'; if (rename(filename, final_filename) == 0) { rval = true; } else { MXS_ERROR("Failed to rename temporary monitor configuration at '%s': %d, %s", filename, errno, mxs_strerror(errno)); } } return rval; } void mon_hangup_failed_servers(MXS_MONITOR* monitor) { for (MXS_MONITORED_SERVER* ptr = monitor->monitored_servers; ptr; ptr = ptr->next) { if (mon_status_changed(ptr) && (!(server_is_usable(ptr->server)) || !(server_is_in_cluster(ptr->server)))) { dcb_hangup_foreach(ptr->server); } } } void mon_report_query_error(MXS_MONITORED_SERVER* db) { MXS_ERROR("Failed to execute query on server '%s' ([%s]:%d): %s", db->server->name, db->server->address, db->server->port, mysql_error(db->con)); } /** * Check if admin is requesting setting or clearing maintenance status on the server and act accordingly. * Should be called at the beginning of a monitor loop. * * @param monitor The target monitor */ void monitor_check_maintenance_requests(MXS_MONITOR* monitor) { /* In theory, the admin may be modifying the server maintenance status during this function. The overall * maintenance flag should be read-written atomically to prevent missing a value. */ int flags_changed = atomic_exchange_int(&monitor->check_maintenance_flag, MAINTENANCE_FLAG_NOCHECK); if (flags_changed != MAINTENANCE_FLAG_NOCHECK) { MXS_MONITORED_SERVER* ptr = monitor->monitored_servers; while (ptr) { // The only server status bit the admin may change is the [Maintenance] bit. int admin_msg = atomic_exchange_int(&ptr->server->maint_request, MAINTENANCE_NO_CHANGE); if (admin_msg == MAINTENANCE_ON) { // TODO: Change to writing MONITORED_SERVER->pending status instead once cleanup done. server_set_status_nolock(ptr->server, SERVER_MAINT); } else if (admin_msg == MAINTENANCE_OFF) { server_clear_status_nolock(ptr->server, SERVER_MAINT); } ptr = ptr->next; } } } void mon_process_state_changes(MXS_MONITOR* monitor, const char* script, uint64_t events) { bool master_down = false; bool master_up = false; for (MXS_MONITORED_SERVER* ptr = monitor->monitored_servers; ptr; ptr = ptr->next) { if (mon_status_changed(ptr)) { /** * The last executed event will be needed if a passive MaxScale is * promoted to an active one and the last event that occurred on * a server was a master_down event. * * In this case, a failover script should be called if no master_up * or new_master events are triggered within a pre-defined time limit. */ mxs_monitor_event_t event = mon_get_event_type(ptr); ptr->server->last_event = event; ptr->server->triggered_at = mxs_clock(); mon_log_state_change(ptr); if (event == MASTER_DOWN_EVENT) { master_down = true; } else if (event == MASTER_UP_EVENT || event == NEW_MASTER_EVENT) { master_up = true; } if (script && *script && (events & event)) { monitor_launch_script(monitor, ptr, script, monitor->script_timeout); } } } if (master_down && master_up) { MXS_NOTICE("Master switch detected: lost a master and gained a new one"); } } static const char* monitor_state_to_string(monitor_state_t state) { switch (state) { case MONITOR_STATE_RUNNING: return "Running"; case MONITOR_STATE_STOPPING: return "Stopping"; case MONITOR_STATE_STOPPED: return "Stopped"; default: mxb_assert(false); return "Unknown"; } } json_t* monitor_parameters_to_json(const MXS_MONITOR* monitor) { json_t* rval = json_object(); const MXS_MODULE* mod = get_module(monitor->module_name, MODULE_MONITOR); config_add_module_params_json(monitor->parameters, {CN_TYPE, CN_MODULE, CN_SERVERS}, config_monitor_params, mod->parameters, rval); return rval; } json_t* monitor_json_data(const MXS_MONITOR* monitor, const char* host) { json_t* rval = json_object(); pthread_mutex_lock((pthread_mutex_t*)&monitor->lock); json_object_set_new(rval, CN_ID, json_string(monitor->name)); json_object_set_new(rval, CN_TYPE, json_string(CN_MONITORS)); json_t* attr = json_object(); json_object_set_new(attr, CN_MODULE, json_string(monitor->module_name)); json_object_set_new(attr, CN_STATE, json_string(monitor_state_to_string(monitor->state))); json_object_set_new(attr, CN_TICKS, json_integer(monitor->ticks)); /** Monitor parameters */ json_object_set_new(attr, CN_PARAMETERS, monitor_parameters_to_json(monitor)); if (monitor->instance && monitor->api->diagnostics_json && monitor->state == MONITOR_STATE_RUNNING) { json_t* diag = monitor->api->diagnostics_json(monitor->instance); if (diag) { json_object_set_new(attr, CN_MONITOR_DIAGNOSTICS, diag); } } json_t* rel = json_object(); if (monitor->monitored_servers) { json_t* mon_rel = mxs_json_relationship(host, MXS_JSON_API_SERVERS); for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { mxs_json_add_relation(mon_rel, db->server->name, CN_SERVERS); } json_object_set_new(rel, CN_SERVERS, mon_rel); } pthread_mutex_unlock((pthread_mutex_t*)&monitor->lock); json_object_set_new(rval, CN_RELATIONSHIPS, rel); json_object_set_new(rval, CN_ATTRIBUTES, attr); json_object_set_new(rval, CN_LINKS, mxs_json_self_link(host, CN_MONITORS, monitor->name)); return rval; } json_t* monitor_to_json(const MXS_MONITOR* monitor, const char* host) { string self = MXS_JSON_API_MONITORS; self += monitor->name; return mxs_json_resource(host, self.c_str(), monitor_json_data(monitor, host)); } json_t* monitor_list_to_json(const char* host) { json_t* rval = json_array(); std::unique_lock guard(monLock); for (MXS_MONITOR* mon = allMonitors; mon; mon = mon->next) { if (mon->active) { json_t* json = monitor_json_data(mon, host); if (json) { json_array_append_new(rval, json); } } } guard.unlock(); return mxs_json_resource(host, MXS_JSON_API_MONITORS, rval); } json_t* monitor_relations_to_server(const SERVER* server, const char* host) { std::vector names; std::unique_lock guard(monLock); for (MXS_MONITOR* mon = allMonitors; mon; mon = mon->next) { pthread_mutex_lock(&mon->lock); if (mon->active) { for (MXS_MONITORED_SERVER* db = mon->monitored_servers; db; db = db->next) { if (db->server == server) { names.push_back(mon->name); break; } } } pthread_mutex_unlock(&mon->lock); } guard.unlock(); json_t* rel = NULL; if (!names.empty()) { rel = mxs_json_relationship(host, MXS_JSON_API_MONITORS); for (std::vector::iterator it = names.begin(); it != names.end(); it++) { mxs_json_add_relation(rel, it->c_str(), CN_MONITORS); } } return rel; } static const char journal_name[] = "monitor.dat"; static const char journal_template[] = "%s/%s/%s"; /** * @brief Remove .tmp suffix and rename file * * @param src File to rename * @return True if file was successfully renamed */ static bool rename_tmp_file(MXS_MONITOR* monitor, const char* src) { bool rval = true; char dest[PATH_MAX + 1]; snprintf(dest, sizeof(dest), journal_template, get_datadir(), monitor->name, journal_name); if (rename(src, dest) == -1) { rval = false; MXS_ERROR("Failed to rename journal file '%s' to '%s': %d, %s", src, dest, errno, mxs_strerror(errno)); } return rval; } /** * @brief Open temporary file * * @param monitor Monitor * @param path Output where the path is stored * @return Opened file or NULL on error */ static FILE* open_tmp_file(MXS_MONITOR* monitor, char* path) { int nbytes = snprintf(path, PATH_MAX, journal_template, get_datadir(), monitor->name, ""); int max_bytes = PATH_MAX - (int)sizeof(journal_name); FILE* rval = NULL; if (nbytes < max_bytes && mxs_mkdir_all(path, 0744)) { strcat(path, journal_name); strcat(path, "XXXXXX"); int fd = mkstemp(path); if (fd == -1) { MXS_ERROR("Failed to open file '%s': %d, %s", path, errno, mxs_strerror(errno)); } else { rval = fdopen(fd, "w"); } } else { MXS_ERROR("Path is too long: %d characters exceeds the maximum path " "length of %d bytes", nbytes, max_bytes); } return rval; } /** * @brief Store server data to in-memory buffer * * @param monitor Monitor * @param data Pointer to in-memory buffer used for storage, should be at least * PATH_MAX bytes long * @param size Size of @c data */ static void store_data(MXS_MONITOR* monitor, MXS_MONITORED_SERVER* master, uint8_t* data, uint32_t size) { uint8_t* ptr = data; /** Store the data length */ mxb_assert(sizeof(size) == MMB_LEN_BYTES); ptr = mxs_set_byte4(ptr, size); /** Then the schema version */ *ptr++ = MMB_SCHEMA_VERSION; /** Store the states of all servers */ for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { *ptr++ = (char)SVT_SERVER; // Value type memcpy(ptr, db->server->name, strlen(db->server->name));// Name of the server ptr += strlen(db->server->name); *ptr++ = '\0'; // Null-terminate the string auto status = db->server->status; static_assert(sizeof(status) == MMB_LEN_SERVER_STATUS, "Status size should be MMB_LEN_SERVER_STATUS bytes"); ptr = maxscale::set_byteN(ptr, status, MMB_LEN_SERVER_STATUS); } /** Store the current root master if we have one */ if (master) { *ptr++ = (char)SVT_MASTER; memcpy(ptr, master->server->name, strlen(master->server->name)); ptr += strlen(master->server->name); *ptr++ = '\0'; // Null-terminate the string } /** Calculate the CRC32 for the complete payload minus the CRC32 bytes */ uint32_t crc = crc32(0L, NULL, 0); crc = crc32(crc, (uint8_t*)data + MMB_LEN_BYTES, size - MMB_LEN_CRC32); mxb_assert(sizeof(crc) == MMB_LEN_CRC32); ptr = mxs_set_byte4(ptr, crc); mxb_assert(ptr - data == size + MMB_LEN_BYTES); } static int get_data_file_path(MXS_MONITOR* monitor, char* path) { int rv = snprintf(path, PATH_MAX, journal_template, get_datadir(), monitor->name, journal_name); return rv; } /** * @brief Open stored journal file * * @param monitor Monitor to reload * @param path Output where path is stored * @return Opened file or NULL on error */ static FILE* open_data_file(MXS_MONITOR* monitor, char* path) { FILE* rval = NULL; int nbytes = get_data_file_path(monitor, path); if (nbytes < PATH_MAX) { if ((rval = fopen(path, "rb")) == NULL && errno != ENOENT) { MXS_ERROR("Failed to open journal file: %d, %s", errno, mxs_strerror(errno)); } } else { MXS_ERROR("Path is too long: %d characters exceeds the maximum path " "length of %d bytes", nbytes, PATH_MAX); } return rval; } /** * Check that memory area contains a null terminator */ static bool has_null_terminator(const char* data, const char* end) { while (data < end) { if (*data == '\0') { return true; } data++; } return false; } /** * Process a generic server */ static const char* process_server(MXS_MONITOR* monitor, const char* data, const char* end) { for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { if (strcmp(db->server->name, data) == 0) { const unsigned char* sptr = (unsigned char*)strchr(data, '\0'); mxb_assert(sptr); sptr++; uint64_t status = maxscale::get_byteN(sptr, MMB_LEN_SERVER_STATUS); db->mon_prev_status = status; server_set_status_nolock(db->server, status); monitor_set_pending_status(db, status); break; } } data += strlen(data) + 1 + MMB_LEN_SERVER_STATUS; return data; } /** * Process a master */ static const char* process_master(MXS_MONITOR* monitor, MXS_MONITORED_SERVER** master, const char* data, const char* end) { if (master) { for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { if (strcmp(db->server->name, data) == 0) { *master = db; break; } } } data += strlen(data) + 1; return data; } /** * Check that the calculated CRC32 matches the one stored on disk */ static bool check_crc32(const uint8_t* data, uint32_t size, const uint8_t* crc_ptr) { uint32_t crc = mxs_get_byte4(crc_ptr); uint32_t calculated_crc = crc32(0L, NULL, 0); calculated_crc = crc32(calculated_crc, data, size); return calculated_crc == crc; } /** * Process the stored journal data */ static bool process_data_file(MXS_MONITOR* monitor, MXS_MONITORED_SERVER** master, const char* data, const char* crc_ptr) { const char* ptr = data; MXB_AT_DEBUG(const char* prevptr = ptr); while (ptr < crc_ptr) { /** All values contain a null terminated string */ if (!has_null_terminator(ptr, crc_ptr)) { MXS_ERROR("Possible corrupted journal file (no null terminator found). Ignoring."); return false; } stored_value_type type = (stored_value_type)ptr[0]; ptr += MMB_LEN_VALUE_TYPE; switch (type) { case SVT_SERVER: ptr = process_server(monitor, ptr, crc_ptr); break; case SVT_MASTER: ptr = process_master(monitor, master, ptr, crc_ptr); break; default: MXS_ERROR("Possible corrupted journal file (unknown stored value). Ignoring."); return false; } mxb_assert(prevptr != ptr); MXB_AT_DEBUG(prevptr = ptr); } mxb_assert(ptr == crc_ptr); return true; } void store_server_journal(MXS_MONITOR* monitor, MXS_MONITORED_SERVER* master) { /** Calculate how much memory we need to allocate */ uint32_t size = MMB_LEN_SCHEMA_VERSION + MMB_LEN_CRC32; for (MXS_MONITORED_SERVER* db = monitor->monitored_servers; db; db = db->next) { /** Each server is stored as a type byte and a null-terminated string * followed by eight byte server status. */ size += MMB_LEN_VALUE_TYPE + strlen(db->server->name) + 1 + MMB_LEN_SERVER_STATUS; } if (master) { /** The master server name is stored as a null terminated string */ size += MMB_LEN_VALUE_TYPE + strlen(master->server->name) + 1; } /** 4 bytes for file length, 1 byte for schema version and 4 bytes for CRC32 */ uint32_t buffer_size = size + MMB_LEN_BYTES; uint8_t* data = (uint8_t*)MXS_MALLOC(buffer_size); char path[PATH_MAX + 1]; if (data) { /** Store the data in memory first and compare the current hash to * the hash of the last stored journal. This isn't a fool-proof * method of detecting changes but any failures are mainly of * theoretical nature. */ store_data(monitor, master, data, size); uint8_t hash[SHA_DIGEST_LENGTH]; SHA1(data, size, hash); if (memcmp(monitor->journal_hash, hash, sizeof(hash)) != 0) { FILE* file = open_tmp_file(monitor, path); if (file) { /** Write the data to a temp file and rename it to the final name */ if (fwrite(data, 1, buffer_size, file) == buffer_size && fflush(file) == 0) { if (!rename_tmp_file(monitor, path)) { unlink(path); } else { memcpy(monitor->journal_hash, hash, sizeof(hash)); } } else { MXS_ERROR("Failed to write journal data to disk: %d, %s", errno, mxs_strerror(errno)); } fclose(file); } } } MXS_FREE(data); } void load_server_journal(MXS_MONITOR* monitor, MXS_MONITORED_SERVER** master) { char path[PATH_MAX]; FILE* file = open_data_file(monitor, path); if (file) { uint32_t size = 0; size_t bytes = fread(&size, 1, MMB_LEN_BYTES, file); mxb_assert(sizeof(size) == MMB_LEN_BYTES); if (bytes == MMB_LEN_BYTES) { /** Payload contents: * * - One byte of schema version * - `size - 5` bytes of data * - Trailing 4 bytes of CRC32 */ char* data = (char*)MXS_MALLOC(size); if (data && (bytes = fread(data, 1, size, file)) == size) { if (*data == MMB_SCHEMA_VERSION) { if (check_crc32((uint8_t*)data, size - MMB_LEN_CRC32, (uint8_t*)data + size - MMB_LEN_CRC32)) { if (process_data_file(monitor, master, data + MMB_LEN_SCHEMA_VERSION, data + size - MMB_LEN_CRC32)) { MXS_NOTICE("Loaded server states from journal file: %s", path); } } else { MXS_ERROR("CRC32 mismatch in journal file. Ignoring."); } } else { MXS_ERROR("Unknown journal schema version: %d", (int)*data); } } else if (data) { if (ferror(file)) { MXS_ERROR("Failed to read journal file: %d, %s", errno, mxs_strerror(errno)); } else { MXS_ERROR("Failed to read journal file: Expected %u bytes, " "read %lu bytes.", size, bytes); } } MXS_FREE(data); } else { if (ferror(file)) { MXS_ERROR("Failed to read journal file length: %d, %s", errno, mxs_strerror(errno)); } else { MXS_ERROR("Failed to read journal file length: Expected %d bytes, " "read %lu bytes.", MMB_LEN_BYTES, bytes); } } fclose(file); } } static void remove_server_journal(MXS_MONITOR* monitor) { char path[PATH_MAX]; if (get_data_file_path(monitor, path) < PATH_MAX) { unlink(path); } else { MXS_ERROR("Path to monitor journal directory is too long."); } } static bool journal_is_stale(MXS_MONITOR* monitor, time_t max_age) { bool is_stale = true; char path[PATH_MAX]; if (get_data_file_path(monitor, path) < PATH_MAX) { struct stat st; if (stat(path, &st) == 0) { time_t tdiff = time(NULL) - st.st_mtim.tv_sec; if (tdiff >= max_age) { MXS_WARNING("Journal file was created %ld seconds ago. Maximum journal " "age is %ld seconds.", tdiff, max_age); } else { is_stale = false; } } else if (errno != ENOENT) { MXS_ERROR("Failed to inspect journal file: %d, %s", errno, mxs_strerror(errno)); } } else { MXS_ERROR("Path to monitor journal directory is too long."); } return is_stale; } MXS_MONITORED_SERVER* mon_get_monitored_server(const MXS_MONITOR* mon, SERVER* search_server) { mxb_assert(mon && search_server); for (MXS_MONITORED_SERVER* iter = mon->monitored_servers; iter != NULL; iter = iter->next) { if (iter->server == search_server) { return iter; } } return NULL; } int mon_config_get_servers(const MXS_CONFIG_PARAMETER* params, const char* key, const MXS_MONITOR* mon, MXS_MONITORED_SERVER*** monitored_servers_out) { mxb_assert(monitored_servers_out != NULL && *monitored_servers_out == NULL); SERVER** servers = NULL; int servers_size = config_get_server_list(params, key, &servers); int found = 0; // All servers in the array must be monitored by the given monitor. if (servers_size > 0) { MXS_MONITORED_SERVER** monitored_array = (MXS_MONITORED_SERVER**)MXS_CALLOC(servers_size, sizeof(MXS_MONITORED_SERVER*)); for (int i = 0; i < servers_size; i++) { MXS_MONITORED_SERVER* mon_serv = mon_get_monitored_server(mon, servers[i]); if (mon_serv != NULL) { monitored_array[found++] = mon_serv; } else { MXS_WARNING("Server '%s' is not monitored by monitor '%s'.", servers[i]->name, mon->name); } } MXS_FREE(servers); mxb_assert(found <= servers_size); if (found == 0) { MXS_FREE(monitored_array); monitored_array = NULL; } else if (found < servers_size) { monitored_array = (MXS_MONITORED_SERVER**)MXS_REALLOC(monitored_array, found); } *monitored_servers_out = monitored_array; } return found; } bool monitor_set_disk_space_threshold(MXS_MONITOR* monitor, const char* disk_space_threshold) { mxb_assert(monitor->state == MONITOR_STATE_STOPPED); MxsDiskSpaceThreshold dst; bool rv = config_parse_disk_space_threshold(&dst, disk_space_threshold); if (rv) { if (!monitor->disk_space_threshold) { monitor->disk_space_threshold = new(std::nothrow) MxsDiskSpaceThreshold; } if (monitor->disk_space_threshold) { monitor->disk_space_threshold->swap(dst); } else { rv = false; } } return rv; } void monitor_debug_wait() { using namespace std::chrono; std::lock_guard guard(monLock); std::map ticks; // Get tick values for all monitors for (MXS_MONITOR* mon = allMonitors; mon; mon = mon->next) { ticks[mon] = mxb::atomic::load(&mon->ticks); } // Wait for all running monitors to advance at least one tick for (MXS_MONITOR* mon = allMonitors; mon; mon = mon->next) { if (mon->state == MONITOR_STATE_RUNNING) { auto start = steady_clock::now(); while (ticks[mon] == mxb::atomic::load(&mon->ticks) && steady_clock::now() - start < seconds(60)) { std::this_thread::sleep_for(milliseconds(100)); } } } } namespace maxscale { MonitorInstance::MonitorInstance(MXS_MONITOR* pMonitor) : m_monitor(pMonitor) , m_master(NULL) , m_thread_running(false) , m_shutdown(0) , m_checked(false) , m_loop_called(get_time_ms()) { } MonitorInstance::~MonitorInstance() { } monitor_state_t MonitorInstance::monitor_state() const { static_assert(sizeof(monitor_state_t) == 4, "Unexpected size for enum"); return (monitor_state_t)atomic_load_uint32((uint32_t*)(&m_monitor->state)); } void MonitorInstance::stop() { // This should only be called by monitor_stop(). NULL worker is allowed since the main worker may // not exist during program start/stop. mxb_assert(mxs_rworker_get_current() == NULL || mxs_rworker_get_current() == mxs_rworker_get(MXS_RWORKER_MAIN)); mxb_assert(Worker::state() != Worker::STOPPED); mxb_assert(monitor_state() == MONITOR_STATE_STOPPING); mxb_assert(m_thread_running.load() == true); Worker::shutdown(); Worker::join(); m_thread_running.store(false, std::memory_order_release); } void MonitorInstance::diagnostics(DCB* pDcb) const { } json_t* MonitorInstance::diagnostics_json() const { return json_object(); } bool MonitorInstance::start(const MXS_CONFIG_PARAMETER* pParams) { // This should only be called by monitor_start(). NULL worker is allowed since the main worker may // not exist during program start/stop. mxb_assert(mxs_rworker_get_current() == NULL || mxs_rworker_get_current() == mxs_rworker_get(MXS_RWORKER_MAIN)); // This can be a bit confusing as the workers are considered to be "finished" when the stop processing. A // better distinction between workers that temporarily stop and permanently stop should be implemented. mxb_assert(Worker::state() == Worker::STOPPED || Worker::state() == Worker::FINISHED); mxb_assert(monitor_state() == MONITOR_STATE_STOPPED); mxb_assert(m_thread_running.load() == false); if (!m_checked) { if (!has_sufficient_permissions()) { MXS_ERROR("Failed to start monitor. See earlier errors for more information."); } else { m_checked = true; } } bool started = false; if (m_checked) { m_master = NULL; if (configure(pParams)) { m_loop_called = get_time_ms() - m_monitor->interval; // Next tick should happen immediately. if (!Worker::start()) { MXS_ERROR("Failed to start worker for monitor '%s'.", m_monitor->name); } else { // Ok, so the thread started. Let's wait until we can be certain the // state has been updated. m_semaphore.wait(); started = m_thread_running.load(std::memory_order_acquire); if (!started) { // Ok, so the initialization failed and the thread will exit. // We need to wait on it so that the thread resources will not leak. Worker::join(); } } } } return started; } // static int64_t MonitorInstance::get_time_ms() { timespec t; MXB_AT_DEBUG(int rv = ) clock_gettime(CLOCK_MONOTONIC_COARSE, &t); mxb_assert(rv == 0); return t.tv_sec * 1000 + (t.tv_nsec / 1000000); } bool MonitorInstance::should_update_disk_space_status(const MXS_MONITORED_SERVER* pMs) const { bool should_check = false; if (m_monitor->disk_space_check_interval && (m_monitor->disk_space_threshold || pMs->server->disk_space_threshold) && (pMs->disk_space_checked != -1)) // -1 means disabled { int64_t now = get_time_ms(); if (now - pMs->disk_space_checked > m_monitor->disk_space_check_interval) { should_check = true; } } return should_check; } namespace { bool check_disk_space_exhausted(MXS_MONITORED_SERVER* pMs, const std::string& path, const maxscale::disk::SizesAndName& san, int32_t max_percentage) { bool disk_space_exhausted = false; int32_t used_percentage = ((san.total() - san.available()) / (double)san.total()) * 100; if (used_percentage >= max_percentage) { MXS_ERROR("Disk space on %s at %s is exhausted; %d%% of the the disk " "mounted on the path %s has been used, and the limit it %d%%.", pMs->server->name, pMs->server->address, used_percentage, path.c_str(), max_percentage); disk_space_exhausted = true; } return disk_space_exhausted; } } void MonitorInstance::update_disk_space_status(MXS_MONITORED_SERVER* pMs) { std::map info; int rv = disk::get_info_by_path(pMs->con, &info); if (rv == 0) { bool disk_space_exhausted = false; MxsDiskSpaceThreshold* pDst = pMs->server->disk_space_threshold ? pMs->server->disk_space_threshold : m_monitor->disk_space_threshold; mxb_assert(pDst); int32_t star_max_percentage = -1; std::set checked_paths; for (auto i = pDst->begin(); i != pDst->end(); ++i) { string path = i->first; int32_t max_percentage = i->second; if (path == "*") { star_max_percentage = max_percentage; } else { auto j = info.find(path); if (j != info.end()) { const disk::SizesAndName& san = j->second; disk_space_exhausted = check_disk_space_exhausted(pMs, path, san, max_percentage); checked_paths.insert(path); } else { MXS_WARNING("Disk space threshold specified for %s even though server %s at %s" "does not have that.", path.c_str(), pMs->server->name, pMs->server->address); } } } if (star_max_percentage != -1) { for (auto j = info.begin(); j != info.end(); ++j) { string path = j->first; if (checked_paths.find(path) == checked_paths.end()) { const disk::SizesAndName& san = j->second; disk_space_exhausted = check_disk_space_exhausted(pMs, path, san, star_max_percentage); } } } if (disk_space_exhausted) { pMs->pending_status |= SERVER_DISK_SPACE_EXHAUSTED; } else { pMs->pending_status &= ~SERVER_DISK_SPACE_EXHAUSTED; } pMs->disk_space_checked = get_time_ms(); } else { SERVER* pServer = pMs->server; if (mysql_errno(pMs->con) == ER_UNKNOWN_TABLE) { // Disable disk space checking for this server. pMs->disk_space_checked = -1; MXS_ERROR("Disk space cannot be checked for %s at %s, because either the " "version %s is too old, or the DISKS information schema plugin " "has not been installed. Disk space checking has been disabled.", pServer->name, pServer->address, pServer->version_string); } else { MXS_ERROR("Checking the disk space for %s at %s failed due to: (%d) %s", pServer->name, pServer->address, mysql_errno(pMs->con), mysql_error(pMs->con)); } } } bool MonitorInstance::configure(const MXS_CONFIG_PARAMETER* pParams) { return true; } bool MonitorInstance::has_sufficient_permissions() const { return true; } void MonitorInstance::flush_server_status() { for (MXS_MONITORED_SERVER* pMs = m_monitor->monitored_servers; pMs; pMs = pMs->next) { if (!server_is_in_maint(pMs->server)) { pMs->server->status = pMs->pending_status; } } } void MonitorInstanceSimple::pre_tick() { } void MonitorInstanceSimple::post_tick() { } void MonitorInstanceSimple::tick() { pre_tick(); for (MXS_MONITORED_SERVER* pMs = m_monitor->monitored_servers; pMs; pMs = pMs->next) { if (!server_is_in_maint(pMs->server)) { pMs->mon_prev_status = pMs->server->status; pMs->pending_status = pMs->server->status; mxs_connect_result_t rval = mon_ping_or_connect_to_db(m_monitor, pMs); if (mon_connection_is_ok(rval)) { monitor_clear_pending_status(pMs, SERVER_AUTH_ERROR); monitor_set_pending_status(pMs, SERVER_RUNNING); if (should_update_disk_space_status(pMs)) { update_disk_space_status(pMs); } update_server_status(pMs); } else { /** * TODO: Move the bits that do not represent a state out of * the server state bits. This would allow clearing the state by * zeroing it out. */ const uint64_t bits_to_clear = ~SERVER_WAS_MASTER; monitor_clear_pending_status(pMs, bits_to_clear); if (mysql_errno(pMs->con) == ER_ACCESS_DENIED_ERROR) { monitor_set_pending_status(pMs, SERVER_AUTH_ERROR); } else { monitor_clear_pending_status(pMs, SERVER_AUTH_ERROR); } if (mon_status_changed(pMs) && mon_print_fail_status(pMs)) { mon_log_connect_error(pMs, rval); } } #if defined (SS_DEBUG) if (mon_status_changed(pMs) || mon_print_fail_status(pMs)) { // The current status is still in pMs->pending_status. SERVER server = {}; server.status = pMs->pending_status; MXS_DEBUG("Backend server [%s]:%d state : %s", pMs->server->address, pMs->server->port, STRSRVSTATUS(&server)); } #endif if (server_is_down(pMs->server)) { pMs->mon_err_count += 1; } else { pMs->mon_err_count = 0; } } } post_tick(); } void MonitorInstance::pre_loop() { } void MonitorInstance::post_loop() { } void MonitorInstance::process_state_changes() { mon_process_state_changes(m_monitor, m_monitor->script, m_monitor->events); } bool MonitorInstance::pre_run() { bool rv = false; if (mysql_thread_init() == 0) { rv = true; // Write and post the semaphore to signal the admin thread that the start is succeeding. m_thread_running.store(true, std::memory_order_release); m_semaphore.post(); load_server_journal(m_monitor, &m_master); pre_loop(); delayed_call(1, &MonitorInstance::call_run_one_tick, this); } else { MXS_ERROR("mysql_thread_init() failed for %s. The monitor cannot start.", m_monitor->name); m_semaphore.post(); } return rv; } void MonitorInstance::post_run() { post_loop(); mysql_thread_end(); } bool MonitorInstance::call_run_one_tick(Worker::Call::action_t action) { if (action == Worker::Call::EXECUTE) { int64_t now = get_time_ms(); // Enough time has passed, if ((now - m_loop_called > static_cast(m_monitor->interval)) // or maintenance flag is set, || atomic_load_int(&m_monitor->check_maintenance_flag) == MAINTENANCE_FLAG_CHECK // or a monitor-specific condition is met. || immediate_tick_required()) { m_loop_called = now; run_one_tick(); now = get_time_ms(); } int64_t ms_to_next_call = m_monitor->interval - (now - m_loop_called); // ms_to_next_call will be negative, if the run_one_tick() call took // longer than one monitor interval. int64_t delay = ((ms_to_next_call <= 0) || (ms_to_next_call >= MXS_MON_BASE_INTERVAL_MS)) ? MXS_MON_BASE_INTERVAL_MS : ms_to_next_call; delayed_call(delay, &MonitorInstance::call_run_one_tick, this); } return false; } void MonitorInstance::run_one_tick() { monitor_check_maintenance_requests(m_monitor); tick(); mxb::atomic::add(&m_monitor->ticks, 1, mxb::atomic::RELAXED); flush_server_status(); process_state_changes(); mon_hangup_failed_servers(m_monitor); store_server_journal(m_monitor, m_master); } bool MonitorInstance::immediate_tick_required() const { return false; } }