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MaxScale/server/core/monitor.cc
Johan Wikman aa11c960b1 2.3.20 Update change date
2020-06-05 09:31:45 +03:00

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/*
* 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: 2024-06-02
*
* 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 <maxscale/monitor.hh>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <chrono>
#include <string>
#include <sstream>
#include <set>
#include <zlib.h>
#include <sys/stat.h>
#include <vector>
#include <mutex>
#include <maxscale/alloc.h>
#include <maxbase/atomic.hh>
#include <maxscale/clock.h>
#include <maxscale/json_api.h>
#include <maxscale/log.h>
#include <maxscale/mariadb.hh>
#include <maxscale/mysql_utils.h>
#include <maxscale/paths.h>
#include <maxscale/pcre2.h>
#include <maxscale/routingworker.h>
#include <maxscale/secrets.h>
#include <maxscale/utils.hh>
#include <maxscale/json_api.h>
#include <mysqld_error.h>
#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<std::mutex> 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<std::mutex> 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_NOTICE("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<std::mutex> 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<std::mutex> guard(monLock);
monitor->active = false;
}
/**
* Shutdown all running monitors
*/
void monitor_stop_all()
{
std::lock_guard<std::mutex> 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<std::mutex> 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<std::mutex> 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<std::mutex> 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<std::mutex> 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<ResultSet> monitor_get_list()
{
std::unique_ptr<ResultSet> set = ResultSet::create({"Monitor", "Status"});
std::lock_guard<std::mutex> 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)
{
auto result = mon_ping_or_connect_to_db(monitor, mondb);
if (!mon_connection_is_ok(result))
{
MXS_ERROR("[%s] Failed to connect to server '%s' ([%s]:%d) when"
" checking monitor user credentials and permissions.",
monitor->name,
mondb->server->name,
mondb->server->address,
mondb->server->port);
if (result != MONITOR_CONN_ACCESS_DENIED)
{
rval = true;
}
}
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<char*>(key);
p.value = const_cast<char*>(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<uint64_t>(-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);
database->con = nullptr;
}
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);
mxs_connect_result_t conn_result = MONITOR_CONN_REFUSED;
for (int i = 0; i < mon->connect_attempts; i++)
{
MYSQL* mysql = mysql_init(nullptr);
mysql_optionsv(mysql, MYSQL_OPT_CONNECT_TIMEOUT, (void*) &mon->connect_timeout);
mysql_optionsv(mysql, MYSQL_OPT_READ_TIMEOUT, (void*) &mon->read_timeout);
mysql_optionsv(mysql, MYSQL_OPT_WRITE_TIMEOUT, (void*) &mon->write_timeout);
mysql_optionsv(mysql, MYSQL_PLUGIN_DIR, get_connector_plugindir());
time_t start = time(nullptr);
bool result = (mxs_mysql_real_connect(mysql, database->server, uname, dpwd) != nullptr);
time_t end = time(nullptr);
if (result)
{
database->con = mysql;
conn_result = MONITOR_CONN_NEWCONN_OK;
break;
}
else
{
auto err = mysql_errno(mysql);
mysql_close(mysql);
if (err == ER_ACCESS_DENIED_ERROR || err == ER_ACCESS_DENIED_NO_PASSWORD_ERROR)
{
conn_result = MONITOR_CONN_ACCESS_DENIED;
}
}
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<std::mutex> 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<std::mutex> 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<std::string> names;
std::unique_lock<std::mutex> 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<std::string>::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_NOTICE("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<std::mutex> guard(monLock);
std::map<MXS_MONITOR*, uint64_t> 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<std::string, disk::SizesAndName> 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<std::string> 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.
*/
monitor_clear_pending_status(pMs, SERVER_DOWN_CLEAR_BITS);
if (rval == MONITOR_CONN_ACCESS_DENIED)
{
monitor_set_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<int64_t>(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;
}
}
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