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61b93185c5a66c3bb97d364e8f72231ea289e002
MaxScale/server/core/monitor.cc
Markus Mäkelä f525822472 Merge branch '2.2' into develop
2018-03-20 13:14:54 +02:00

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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: 2020-01-01
*
* 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 <maxscale/monitor.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <sstream>
#include <set>
#include <zlib.h>
#include <sys/stat.h>
#include <vector>
#include <maxscale/alloc.h>
#include <maxscale/hk_heartbeat.h>
#include <maxscale/json_api.h>
#include <maxscale/log_manager.h>
#include <maxscale/mysql_utils.h>
#include <maxscale/paths.h>
#include <maxscale/pcre2.h>
#include <maxscale/secrets.h>
#include <maxscale/spinlock.h>
#include <maxscale/utils.h>
#include <maxscale/json_api.h>
#include <mysqld_error.h>
#include "internal/config.h"
#include "internal/externcmd.h"
#include "internal/monitor.h"
#include "internal/modules.h"
/** Schema version, journals must have a matching version */
#define MMB_SCHEMA_VERSION 1
/** 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 4
/** 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_READ_TIMEOUT[] = "backend_read_timeout";
const char CN_BACKEND_WRITE_TIMEOUT[] = "backend_write_timeout";
const char CN_BACKEND_CONNECT_TIMEOUT[] = "backend_connect_timeout";
const char CN_MONITOR_INTERVAL[] = "monitor_interval";
const char CN_JOURNAL_MAX_AGE[] = "journal_max_age";
const char CN_SCRIPT_TIMEOUT[] = "script_timeout";
const char CN_SCRIPT[] = "script";
const char CN_EVENTS[] = "events";
static MXS_MONITOR *allMonitors = NULL;
static SPINLOCK monLock = SPINLOCK_INIT;
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);
/** Server type specific bits */
static unsigned int server_type_bits = SERVER_MASTER | SERVER_SLAVE |
SERVER_JOINED | SERVER_NDB;
/** All server bits */
static unsigned int all_server_bits = SERVER_RUNNING | SERVER_MAINT |
SERVER_MASTER | SERVER_SLAVE |
SERVER_JOINED | SERVER_NDB;
/**
* Allocate 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_alloc(const char *name, const char *module)
{
char* my_name = MXS_STRDUP(name);
char *my_module = MXS_STRDUP(module);
MXS_MONITOR *mon = (MXS_MONITOR *)MXS_MALLOC(sizeof(MXS_MONITOR));
if (!my_name || !mon || !my_module)
{
MXS_FREE(my_name);
MXS_FREE(mon);
MXS_FREE(my_module);
return NULL;
}
if ((mon->module = (MXS_MONITOR_OBJECT*)load_module(module, MODULE_MONITOR)) == NULL)
{
MXS_ERROR("Unable to load monitor module '%s'.", my_name);
MXS_FREE(my_name);
MXS_FREE(mon);
return NULL;
}
mon->active = true;
mon->state = MONITOR_STATE_ALLOC;
mon->name = my_name;
mon->module_name = my_module;
mon->handle = NULL;
mon->monitored_servers = NULL;
*mon->password = '\0';
*mon->user = '\0';
mon->read_timeout = DEFAULT_READ_TIMEOUT;
mon->write_timeout = DEFAULT_WRITE_TIMEOUT;
mon->connect_timeout = DEFAULT_CONNECT_TIMEOUT;
mon->connect_attempts = DEFAULT_CONNECTION_ATTEMPTS;
mon->interval = DEFAULT_MONITOR_INTERVAL;
mon->journal_max_age = DEFAULT_JOURNAL_MAX_AGE;
mon->script_timeout = DEFAULT_SCRIPT_TIMEOUT;
mon->parameters = NULL;
mon->server_pending_changes = false;
memset(mon->journal_hash, 0, sizeof(mon->journal_hash));
spinlock_init(&mon->lock);
spinlock_acquire(&monLock);
mon->next = allMonitors;
allMonitors = mon;
spinlock_release(&monLock);
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_free(MXS_MONITOR *mon)
{
MXS_MONITOR *ptr;
mon->module->stopMonitor(mon);
mon->state = MONITOR_STATE_FREED;
spinlock_acquire(&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;
}
}
spinlock_release(&monLock);
config_parameter_free(mon->parameters);
monitor_server_free_all(mon->monitored_servers);
MXS_FREE(mon->name);
MXS_FREE(mon->module_name);
MXS_FREE(mon);
}
/**
* Start an individual monitor that has previously been stopped.
*
* @param monitor The Monitor that should be started
*/
void
monitorStart(MXS_MONITOR *monitor, const MXS_CONFIG_PARAMETER* params)
{
if (monitor)
{
spinlock_acquire(&monitor->lock);
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->handle = (*monitor->module->startMonitor)(monitor, params)))
{
monitor->state = MONITOR_STATE_RUNNING;
}
else
{
MXS_ERROR("Failed to start monitor '%s'.", monitor->name);
}
spinlock_release(&monitor->lock);
}
}
/**
* Start all monitors
*/
void monitorStartAll()
{
MXS_MONITOR *ptr;
spinlock_acquire(&monLock);
ptr = allMonitors;
while (ptr)
{
if (ptr->active)
{
monitorStart(ptr, ptr->parameters);
}
ptr = ptr->next;
}
spinlock_release(&monLock);
}
/**
* Stop a given monitor
*
* @param monitor The monitor to stop
*/
void
monitorStop(MXS_MONITOR *monitor)
{
if (monitor)
{
spinlock_acquire(&monitor->lock);
/** Only stop the monitor if it is running */
if (monitor->state == MONITOR_STATE_RUNNING)
{
monitor->state = MONITOR_STATE_STOPPING;
monitor->module->stopMonitor(monitor);
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;
}
}
spinlock_release(&monitor->lock);
}
}
void monitorDestroy(MXS_MONITOR* monitor)
{
spinlock_acquire(&monLock);
monitor->active = false;
spinlock_release(&monLock);
}
/**
* Shutdown all running monitors
*/
void
monitorStopAll()
{
MXS_MONITOR *ptr;
spinlock_acquire(&monLock);
ptr = allMonitors;
while (ptr)
{
if (ptr->active)
{
monitorStop(ptr);
}
ptr = ptr->next;
}
spinlock_release(&monLock);
}
/**
* 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 monitorAddServer(MXS_MONITOR *mon, SERVER *server)
{
bool rval = false;
if (monitor_server_in_use(server))
{
MXS_ERROR("Server '%s' is already monitored.", server->unique_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;
db->new_event = true;
/** 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)
{
monitorStop(mon);
}
spinlock_acquire(&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;
}
spinlock_release(&mon->lock);
if (old_state == MONITOR_STATE_RUNNING)
{
monitorStart(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 monitorRemoveServer(MXS_MONITOR *mon, SERVER *server)
{
monitor_state_t old_state = mon->state;
if (old_state == MONITOR_STATE_RUNNING)
{
monitorStop(mon);
}
spinlock_acquire(&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;
}
}
spinlock_release(&mon->lock);
if (ptr)
{
monitor_server_free(ptr);
}
if (old_state == MONITOR_STATE_RUNNING)
{
monitorStart(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
monitorAddUser(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
monitorShowAll(DCB *dcb)
{
MXS_MONITOR *ptr;
spinlock_acquire(&monLock);
ptr = allMonitors;
while (ptr)
{
if (ptr->active)
{
monitorShow(dcb, ptr);
}
ptr = ptr->next;
}
spinlock_release(&monLock);
}
/**
* Show a single monitor
*
* @param dcb DCB for printing output
*/
void
monitorShow(DCB *dcb, MXS_MONITOR *monitor)
{
const char *state;
switch (monitor->state)
{
case MONITOR_STATE_RUNNING:
state = "Running";
break;
case MONITOR_STATE_STOPPING:
state = "Stopping";
break;
case MONITOR_STATE_STOPPED:
state = "Stopped";
break;
case MONITOR_STATE_ALLOC:
state = "Allocated";
break;
default:
state = "Unknown";
break;
}
dcb_printf(dcb, "Monitor: %p\n", monitor);
dcb_printf(dcb, "Name: %s\n", monitor->name);
dcb_printf(dcb, "State: %s\n", state);
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->name, db->server->port);
sep = ", ";
}
dcb_printf(dcb, "\n");
if (monitor->handle)
{
if (monitor->module->diagnostics)
{
monitor->module->diagnostics(dcb, monitor);
}
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
monitorList(DCB *dcb)
{
MXS_MONITOR *ptr;
spinlock_acquire(&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");
spinlock_release(&monLock);
}
/**
* 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)
{
MXS_MONITOR *ptr;
spinlock_acquire(&monLock);
ptr = allMonitors;
while (ptr)
{
if (!strcmp(ptr->name, name) && ptr->active)
{
break;
}
ptr = ptr->next;
}
spinlock_release(&monLock);
return ptr;
}
/**
* 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;
spinlock_acquire(&monLock);
for (MXS_MONITOR *ptr = allMonitors; ptr; ptr = ptr->next)
{
if (strcmp(ptr->name, name) == 0 && strcmp(ptr->module_name, module) == 0)
{
ss_dassert(!ptr->active);
ptr->active = true;
rval = ptr;
}
}
spinlock_release(&monLock);
return rval;
}
/**
* Set the monitor sampling interval.
*
* @param mon The monitor instance
* @param interval The sampling interval in milliseconds
*/
void
monitorSetInterval(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 monitorSetJournalMaxAge(MXS_MONITOR *mon, time_t value)
{
mon->journal_max_age = value;
}
void monitorSetScriptTimeout(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 monitorSetNetworkTimeout(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);
ss_dassert(!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;
}
/**
* Provide a row to the result set that defines the set of monitors
*
* @param set The result set
* @param data The index of the row to send
* @return The next row or NULL
*/
static RESULT_ROW *
monitorRowCallback(RESULTSET *set, void *data)
{
int *rowno = (int *)data;
int i = 0;;
char buf[20];
RESULT_ROW *row;
MXS_MONITOR *ptr;
spinlock_acquire(&monLock);
ptr = allMonitors;
while (i < *rowno && ptr)
{
i++;
ptr = ptr->next;
}
if (ptr == NULL)
{
spinlock_release(&monLock);
MXS_FREE(data);
return NULL;
}
(*rowno)++;
row = resultset_make_row(set);
resultset_row_set(row, 0, ptr->name);
resultset_row_set(row, 1, ptr->state & MONITOR_STATE_RUNNING
? "Running" : "Stopped");
spinlock_release(&monLock);
return row;
}
/**
* Return a resultset that has the current set of monitors in it
*
* @return A Result set
*/
RESULTSET *
monitorGetList()
{
RESULTSET *set;
int *data;
if ((data = (int *)MXS_MALLOC(sizeof(int))) == NULL)
{
return NULL;
}
*data = 0;
if ((set = resultset_create(monitorRowCallback, data)) == NULL)
{
MXS_FREE(data);
return NULL;
}
resultset_add_column(set, "Monitor", 20, COL_TYPE_VARCHAR);
resultset_add_column(set, "Status", 10, COL_TYPE_VARCHAR);
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_ping_or_connect_to_db(monitor, mondb) != MONITOR_CONN_OK)
{
MXS_ERROR("[%s] Failed to connect to server '%s' ([%s]:%d) when"
" checking monitor user credentials and permissions: %s",
monitor->name, mondb->server->unique_name, mondb->server->name,
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 monitorAddParameters(MXS_MONITOR *monitor, MXS_CONFIG_PARAMETER *params)
{
spinlock_acquire(&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;
}
spinlock_release(&monitor->lock);
}
bool monitorRemoveParameter(MXS_MONITOR *monitor, const char *key)
{
MXS_CONFIG_PARAMETER *prev = NULL;
bool rval = false;
spinlock_acquire(&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;
}
spinlock_release(&monitor->lock);
return rval;
}
void mon_alter_parameter(MXS_MONITOR* monitor, const char* key, const char* value)
{
spinlock_acquire(&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;
}
}
spinlock_release(&monitor->lock);
}
/**
* Set a pending status bit in the monitor server
*
* @param server The server to update
* @param bit The bit to clear for the server
*/
void
monitor_set_pending_status(MXS_MONITORED_SERVER *ptr, int bit)
{
ptr->pending_status |= bit;
}
/**
* Clear a pending status bit in the monitor server
*
* @param server The server to update
* @param bit The bit to clear for the server
*/
void
monitor_clear_pending_status(MXS_MONITORED_SERVER *ptr, int 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;
unsigned int prev = node->mon_prev_status & all_server_bits;
unsigned int present = node->server->status & all_server_bits;
if (prev == present)
{
/* This should never happen */
ss_dassert(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. */
ss_dassert(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 */
unsigned int prev_bits = prev & (SERVER_MASTER | SERVER_SLAVE);
unsigned int 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 */
ss_dassert(false);
break;
}
ss_dassert(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;
}
}
ss_dassert(false);
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->name,
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->name,
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<uint32_t>(-1))
{
unsigned int old_status = mon_srv->mon_prev_status & all_server_bits;
unsigned int 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->name << "]:" << 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, "$INITIATOR"))
{
char initiator[strlen(ptr->server->name) + 24]; // Extra space for port
snprintf(initiator, sizeof(initiator), "[%s]:%d", ptr->server->name, ptr->server->port);
externcmd_substitute_arg(cmd, "[$]INITIATOR", initiator);
}
if (externcmd_matches(cmd, "$PARENT"))
{
std::stringstream ss;
MXS_MONITORED_SERVER* parent = find_parent_node(mon->monitored_servers, ptr);
if (parent)
{
ss << "[" << parent->server->name << "]:" << parent->server->port;
}
externcmd_substitute_arg(cmd, "[$]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
{
ss_dassert(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;
}
ss_dassert(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, if connection does not exist or ping fails, connect to a database. 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 MONITOR_CONN_OK if the connection is OK, else the reason for the failure
*/
mxs_connect_result_t
mon_ping_or_connect_to_db(MXS_MONITOR* mon, MXS_MONITORED_SERVER *database)
{
/** Return if the connection is OK */
if (database->con && mysql_ping(database->con) == 0)
{
return MONITOR_CONN_OK;
}
if (database->con)
{
mysql_close(database->con);
}
mxs_connect_result_t rval = 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)
{
rval = MONITOR_CONN_OK;
break;
}
}
if (rval == MONITOR_CONN_REFUSED &&
(int)difftime(end, start) >= mon->connect_timeout)
{
rval = MONITOR_CONN_TIMEOUT;
}
MXS_FREE(dpwd);
}
return rval;
}
/**
* 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_connect_to_db
*/
void
mon_log_connect_error(MXS_MONITORED_SERVER* database, mxs_connect_result_t rval)
{
MXS_ERROR(rval == MONITOR_CONN_TIMEOUT ?
"Monitor timed out when connecting to server [%s]:%d : \"%s\"" :
"Monitor was unable to connect to server [%s]:%d : \"%s\"",
database->server->name, database->server->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->unique_name, ptr->server->name, 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;
spinlock_acquire(&monLock);
for (MXS_MONITOR *mon = allMonitors; mon && !rval; mon = mon->next)
{
spinlock_acquire(&mon->lock);
if (mon->active)
{
for (MXS_MONITORED_SERVER *db = mon->monitored_servers; db && !rval; db = db->next)
{
if (db->server == server)
{
rval = mon;
}
}
}
spinlock_release(&mon->lock);
}
spinlock_release(&monLock);
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;
}
spinlock_acquire(&monitor->lock);
dprintf(file, "[%s]\n", monitor->name);
dprintf(file, "%s=monitor\n", CN_TYPE);
dprintf(file, "%s=%s\n", CN_MODULE, monitor->module_name);
dprintf(file, "%s=%s\n", CN_USER, monitor->user);
dprintf(file, "%s=%s\n", CN_PASSWORD, monitor->password);
dprintf(file, "%s=%lu\n", CN_MONITOR_INTERVAL, monitor->interval);
dprintf(file, "%s=%d\n", CN_BACKEND_CONNECT_TIMEOUT, monitor->connect_timeout);
dprintf(file, "%s=%d\n", CN_BACKEND_WRITE_TIMEOUT, monitor->write_timeout);
dprintf(file, "%s=%d\n", CN_BACKEND_READ_TIMEOUT, monitor->read_timeout);
dprintf(file, "%s=%d\n", CN_BACKEND_CONNECT_ATTEMPTS, monitor->connect_attempts);
dprintf(file, "%s=%ld\n", CN_JOURNAL_MAX_AGE, monitor->journal_max_age);
dprintf(file, "%s=%d\n", CN_SCRIPT_TIMEOUT, monitor->script_timeout);
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->unique_name);
}
dprintf(file, "\n");
}
const char* params[] =
{
CN_TYPE,
CN_MODULE,
CN_USER,
CN_PASSWORD,
"passwd", // TODO: Remove this
CN_MONITOR_INTERVAL,
CN_BACKEND_CONNECT_TIMEOUT,
CN_BACKEND_WRITE_TIMEOUT,
CN_BACKEND_READ_TIMEOUT,
CN_BACKEND_CONNECT_ATTEMPTS,
CN_JOURNAL_MAX_AGE,
CN_SCRIPT_TIMEOUT,
CN_SERVERS
};
std::set<std::string> param_set(params, params + sizeof(params) / sizeof(params[0]));
for (MXS_CONFIG_PARAMETER* p = monitor->parameters; p; p = p->next)
{
if (param_set.find(p->name) == param_set.end())
{
dprintf(file, "%s=%s\n", p->name, p->value);
}
}
spinlock_release(&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, '.');
ss_dassert(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_RUNNING(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->unique_name, db->server->name,
db->server->port, mysql_error(db->con));
}
/**
* Acquire locks on all servers monitored by this monitor. There should
* only be max 1 monitor per server.
* @param monitor The target monitor
*/
void lock_monitor_servers(MXS_MONITOR *monitor)
{
MXS_MONITORED_SERVER *ptr = monitor->monitored_servers;
while (ptr)
{
spinlock_acquire(&ptr->server->lock);
ptr = ptr->next;
}
}
/**
* Release locks on all servers monitored by this monitor. There should
* only be max 1 monitor per server.
* @param monitor The target monitor
*/
void release_monitor_servers(MXS_MONITOR *monitor)
{
MXS_MONITORED_SERVER *ptr = monitor->monitored_servers;
while (ptr)
{
spinlock_release(&ptr->server->lock);
ptr = ptr->next;
}
}
/**
* Sets the current status of all servers monitored by this monitor to
* the pending status. This should only be called at the beginning of
* a monitor loop, after the servers are locked.
* @param monitor The target monitor
*/
void servers_status_pending_to_current(MXS_MONITOR *monitor)
{
MXS_MONITORED_SERVER *ptr = monitor->monitored_servers;
while (ptr)
{
ptr->server->status = ptr->server->status_pending;
ptr = ptr->next;
}
monitor->server_pending_changes = false;
}
/**
* Sets the pending status of all servers monitored by this monitor to
* the current status. This should only be called at the end of
* a monitor loop, before the servers are released.
* @param monitor The target monitor
*/
void servers_status_current_to_pending(MXS_MONITOR *monitor)
{
MXS_MONITORED_SERVER *ptr = monitor->monitored_servers;
while (ptr)
{
ptr->server->status_pending = ptr->server->status;
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 = hkheartbeat;
ptr->server->active_event = !config_get_global_options()->passive;
ptr->new_event = true;
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)
{
// We either lost the master or gained a new one
if (master_down)
{
monitor->master_has_failed = true;
}
else if (master_up)
{
monitor->master_has_failed = false;
}
}
else if (master_down && master_up)
{
MXS_INFO("Master switch detected: lost a master and gained a new one");
}
}
static const char* monitor_state_to_string(int state)
{
switch (state)
{
case MONITOR_STATE_RUNNING:
return "Running";
case MONITOR_STATE_STOPPING:
return "Stopping";
case MONITOR_STATE_STOPPED:
return "Stopped";
case MONITOR_STATE_ALLOC:
return "Allocated";
default:
ss_dassert(false);
return "Unknown";
}
}
json_t* monitor_parameters_to_json(const MXS_MONITOR* monitor)
{
json_t* rval = json_object();
json_object_set_new(rval, CN_USER, json_string(monitor->user));
json_object_set_new(rval, CN_PASSWORD, json_string(monitor->password));
json_object_set_new(rval, CN_MONITOR_INTERVAL, json_integer(monitor->interval));
json_object_set_new(rval, CN_BACKEND_CONNECT_TIMEOUT, json_integer(monitor->connect_timeout));
json_object_set_new(rval, CN_BACKEND_READ_TIMEOUT, json_integer(monitor->read_timeout));
json_object_set_new(rval, CN_BACKEND_WRITE_TIMEOUT, json_integer(monitor->write_timeout));
json_object_set_new(rval, CN_BACKEND_CONNECT_ATTEMPTS, json_integer(monitor->connect_attempts));
json_object_set_new(rval, CN_JOURNAL_MAX_AGE, json_integer(monitor->journal_max_age));
json_object_set_new(rval, CN_SCRIPT_TIMEOUT, json_integer(monitor->script_timeout));
/** Add custom module parameters */
const MXS_MODULE* mod = get_module(monitor->module_name, MODULE_MONITOR);
config_add_module_params_json(mod, monitor->parameters, config_monitor_params, rval);
/** Don't show the default value for events if no script is defined */
if (json_object_get(rval, CN_SCRIPT) == NULL)
{
json_object_del(rval, CN_EVENTS);
}
return rval;
}
json_t* monitor_json_data(const MXS_MONITOR* monitor, const char* host)
{
json_t* rval = json_object();
spinlock_acquire(&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)));
/** Monitor parameters */
json_object_set_new(attr, CN_PARAMETERS, monitor_parameters_to_json(monitor));
if (monitor->handle && monitor->module->diagnostics_json)
{
json_t* diag = monitor->module->diagnostics_json(monitor);
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->unique_name, CN_SERVERS);
}
json_object_set_new(rel, CN_SERVERS, mon_rel);
}
spinlock_release(&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();
spinlock_acquire(&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);
}
}
}
spinlock_release(&monLock);
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;
spinlock_acquire(&monLock);
for (MXS_MONITOR* mon = allMonitors; mon; mon = mon->next)
{
spinlock_acquire(&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;
}
}
}
spinlock_release(&mon->lock);
}
spinlock_release(&monLock);
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 */
ss_dassert(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->unique_name, strlen(db->server->unique_name)); // Name of the server
ptr += strlen(db->server->unique_name);
*ptr++ = '\0'; // Null-terminate the string
uint32_t status = db->server->status; // Server status as 4 byte integer
ss_dassert(sizeof(status) == MMB_LEN_SERVER_STATUS);
ptr = mxs_set_byte4(ptr, status);
}
/** Store the current root master if we have one */
if (master)
{
*ptr++ = (char)SVT_MASTER;
memcpy(ptr, master->server->unique_name, strlen(master->server->unique_name));
ptr += strlen(master->server->unique_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);
ss_dassert(sizeof(crc) == MMB_LEN_CRC32);
ptr = mxs_set_byte4(ptr, crc);
ss_dassert(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->unique_name, data) == 0)
{
const unsigned char *sptr = (unsigned char*)strchr(data, '\0');
ss_dassert(sptr);
sptr++;
uint32_t state = mxs_get_byte4(sptr);
db->mon_prev_status = state;
db->server->status_pending = state;
server_set_status_nolock(db->server, state);
monitor_set_pending_status(db, state);
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->unique_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;
ss_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;
}
ss_dassert(prevptr != ptr);
ss_debug(prevptr = ptr);
}
ss_dassert(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->unique_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->unique_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);
ss_dassert(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)
{
ss_dassert(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)
{
ss_dassert(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]->unique_name, mon->name);
}
}
MXS_FREE(servers);
ss_dassert(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;
}
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