563 lines
20 KiB
C++
563 lines
20 KiB
C++
/*
|
|
* Copyright (c) 2018 MariaDB Corporation Ab
|
|
*
|
|
* Use of this software is governed by the Business Source License included
|
|
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
|
|
*
|
|
* Change Date: 2022-01-01
|
|
*
|
|
* On the date above, in accordance with the Business Source License, use
|
|
* of this software will be governed by version 2 or later of the General
|
|
* Public License.
|
|
*/
|
|
#pragma once
|
|
#include "mariadbmon_common.hh"
|
|
#include <functional>
|
|
#include <string>
|
|
#include <memory>
|
|
#include <maxbase/stopwatch.hh>
|
|
#include <maxsql/mariadb.hh>
|
|
#include <maxscale/monitor.hh>
|
|
#include "server_utils.hh"
|
|
|
|
class MariaDBServer;
|
|
// Server pointer array
|
|
typedef std::vector<MariaDBServer*> ServerArray;
|
|
|
|
/**
|
|
* Data required for checking replication topology cycles and other graph algorithms. This data is mostly
|
|
* used by the monitor object, as the data only makes sense in relation to other nodes.
|
|
*/
|
|
struct NodeData
|
|
{
|
|
// Default values for index parameters
|
|
static const int INDEX_NOT_VISITED = 0;
|
|
static const int INDEX_FIRST = 1;
|
|
// Default values for the cycle
|
|
static const int CYCLE_NONE = 0;
|
|
static const int CYCLE_FIRST = 1;
|
|
// Default value for reach
|
|
static const int REACH_UNKNOWN = -1;
|
|
|
|
// Bookkeeping for graph searches. May be overwritten by multiple algorithms.
|
|
int index; /* Marks the order in which this node was visited. */
|
|
int lowest_index; /* The lowest index node this node has in its subtree. */
|
|
bool in_stack; /* Is this node currently is the search stack. */
|
|
|
|
// Results from algorithm runs. Should only be overwritten when server data has been queried.
|
|
int cycle; /* Which cycle is this node part of, if any. */
|
|
int reach; /* How many servers replicate from this server or its children. */
|
|
ServerArray parents; /* Which nodes is this node replicating from. External masters
|
|
* excluded. */
|
|
ServerArray children; /* Which nodes are replicating from this node. */
|
|
std::vector<int64_t> external_masters; /* Server id:s of external masters. */
|
|
|
|
NodeData();
|
|
|
|
/**
|
|
* Reset result data to default values. Should be ran when starting an iteration.
|
|
*/
|
|
void reset_results();
|
|
|
|
/**
|
|
* Reset index data. Should be ran before an algorithm run.
|
|
*/
|
|
void reset_indexes();
|
|
};
|
|
|
|
/**
|
|
* Monitor specific information about a server. Eventually, this will be the primary data structure handled
|
|
* by the monitor. These are initialized in @c init_server_info.
|
|
*/
|
|
class MariaDBServer
|
|
{
|
|
public:
|
|
enum class server_type
|
|
{
|
|
UNKNOWN, /* Totally unknown. Server has not been connected to yet. */
|
|
NORMAL, /* A normal MariaDB/MySQL server, possibly supported. */
|
|
BINLOG_ROUTER, /* MaxScale binlog server. Requires special handling. */
|
|
CLUSTRIX /* Clustrix server. Requires special handling. */
|
|
};
|
|
|
|
enum class BinlogMode
|
|
{
|
|
BINLOG_ON,
|
|
BINLOG_OFF
|
|
};
|
|
|
|
// Class which encapsulates server capabilities depending on its version.
|
|
class Capabilities
|
|
{
|
|
public:
|
|
bool basic_support = false; // Is the server version supported by the monitor at all?
|
|
bool gtid = false; // Supports MariaDB gtid? Required for failover etc.
|
|
bool max_statement_time = false; // Supports max_statement_time?
|
|
};
|
|
|
|
// This class groups some miscellaneous replication related settings together.
|
|
class ReplicationSettings
|
|
{
|
|
public:
|
|
bool gtid_strict_mode = false; /* Enable additional checks for replication */
|
|
bool log_bin = false; /* Is binary logging enabled? */
|
|
bool log_slave_updates = false; /* Does the slave write replicated events to binlog? */
|
|
};
|
|
|
|
/* Monitored server base class/struct. MariaDBServer does not own the struct, it is not freed
|
|
* (or connection closed) when a MariaDBServer is destroyed. */
|
|
MXS_MONITORED_SERVER* m_server_base = NULL;
|
|
/* What position this server has in the monitor config? Used for tiebreaking between servers. */
|
|
int m_config_index = 0;
|
|
|
|
server_type m_srv_type = server_type::UNKNOWN; /* Server type. */
|
|
Capabilities m_capabilities; /* Server capabilities */
|
|
|
|
int64_t m_server_id = SERVER_ID_UNKNOWN; /* Value of @@server_id. Valid values are
|
|
* 32bit unsigned. */
|
|
int64_t m_gtid_domain_id = GTID_DOMAIN_UNKNOWN; /* The value of gtid_domain_id, the domain which is used
|
|
* for new non-replicated events. */
|
|
|
|
bool m_read_only = false; /* Value of @@read_only */
|
|
GtidList m_gtid_current_pos; /* Gtid of latest event. */
|
|
GtidList m_gtid_binlog_pos; /* Gtid of latest event written to binlog. */
|
|
SlaveStatusArray m_slave_status; /* Data returned from SHOW (ALL) SLAVE(S) STATUS */
|
|
NodeData m_node; /* Replication topology data */
|
|
|
|
/* Replication lag of the server. Used during calculation so that the actual SERVER struct is
|
|
* only written to once. */
|
|
int m_replication_lag = SERVER::RLAG_UNDEFINED;
|
|
/* Copy of same field in monitor object. TODO: pass in struct when adding concurrent updating. */
|
|
bool m_assume_unique_hostnames = true;
|
|
/* Has anything that could affect replication topology changed this iteration?
|
|
* Causes: server id, slave connections, read-only. */
|
|
bool m_topology_changed = true;
|
|
/* Miscellaneous replication related settings. These are not normally queried from the server, call
|
|
* 'update_replication_settings' before use. */
|
|
ReplicationSettings m_rpl_settings;
|
|
|
|
bool m_print_update_errormsg = true; /* Should an update error be printed? */
|
|
|
|
MariaDBServer(MXS_MONITORED_SERVER* monitored_server, int config_index,
|
|
bool assume_unique_hostnames = true);
|
|
|
|
/**
|
|
* Print server information to a json object.
|
|
*
|
|
* @return Json diagnostics object
|
|
*/
|
|
json_t* to_json() const;
|
|
|
|
/**
|
|
* Print server information to a string.
|
|
*
|
|
* @return Diagnostics string
|
|
*/
|
|
std::string diagnostics() const;
|
|
|
|
/**
|
|
* Query this server.
|
|
*/
|
|
void monitor_server();
|
|
|
|
/**
|
|
* Update server version. This method should be called after (re)connecting to a
|
|
* backend. Calling this every monitoring loop is overkill.
|
|
*/
|
|
void update_server_version();
|
|
|
|
/**
|
|
* Checks monitor permissions on the server. Sets/clears the SERVER_AUTH_ERROR bit.
|
|
*/
|
|
void check_permissions();
|
|
|
|
/**
|
|
* Calculate how many events are left in the relay log of the slave connection.
|
|
*
|
|
* @param slave_conn The slave connection to calculate for
|
|
* @return Number of events in relay log. Always 0 or greater.
|
|
*/
|
|
uint64_t relay_log_events(const SlaveStatus& slave_conn);
|
|
|
|
/**
|
|
* Execute a query which returns data. The results are returned as a unique pointer to a QueryResult
|
|
* object. The column names of the results are assumed unique.
|
|
*
|
|
* @param query The query
|
|
* @param errmsg_out Where to store an error message if query fails. Can be null.
|
|
* @return Pointer to query results, or an empty pointer on failure
|
|
*/
|
|
std::unique_ptr<mxq::QueryResult> execute_query(const std::string& query, std::string* errmsg_out = NULL);
|
|
|
|
/**
|
|
* execute_cmd_ex with query retry ON.
|
|
*/
|
|
bool execute_cmd(const std::string& cmd, std::string* errmsg_out = NULL);
|
|
|
|
/**
|
|
* execute_cmd_ex with query retry OFF.
|
|
*/
|
|
bool execute_cmd_no_retry(const std::string& cmd,
|
|
std::string* errmsg_out = NULL, unsigned int* errno_out = NULL);
|
|
|
|
/**
|
|
* Update server slave connection information.
|
|
*
|
|
* @param gtid_domain Which gtid domain should be parsed.
|
|
* @param errmsg_out Where to store an error message if query fails. Can be null.
|
|
* @return True on success
|
|
*/
|
|
bool do_show_slave_status(std::string* errmsg_out = NULL);
|
|
|
|
/**
|
|
* Query gtid_current_pos and gtid_binlog_pos and save the values to the server.
|
|
*
|
|
* @param errmsg_out Where to store an error message if query fails. Can be null.
|
|
* @return True if query succeeded
|
|
*/
|
|
bool update_gtids(std::string* errmsg_out = NULL);
|
|
|
|
/**
|
|
* Query a few miscellaneous replication settings.
|
|
*
|
|
* @param error_out Query error output
|
|
* @return True on success
|
|
*/
|
|
bool update_replication_settings(std::string* error_out = NULL);
|
|
|
|
/**
|
|
* Query and save server_id, read_only and (if 10.X) gtid_domain_id.
|
|
*
|
|
* @param errmsg_out Where to store an error message if query fails. Can be null.
|
|
* @return True on success.
|
|
*/
|
|
bool read_server_variables(std::string* errmsg_out = NULL);
|
|
|
|
/**
|
|
* Print warnings if gtid_strict_mode or log_slave_updates is off. Does not query the server,
|
|
* so 'update_replication_settings' should have been called recently to update the values.
|
|
*/
|
|
void warn_replication_settings() const;
|
|
|
|
/**
|
|
* Wait until server catches up to demotion target. Only considers gtid domains common
|
|
* to this server and the target. The gtid compared to on the demotion target is 'gtid_binlog_pos'.
|
|
* It is not updated during this method.
|
|
*
|
|
* The gtid used for comparison on this server is 'gtid_binlog_pos' if this server has both 'log_bin'
|
|
* and 'log_slave_updates' on, and 'gtid_current_pos' otherwise. This server is updated during the
|
|
* method.
|
|
*
|
|
* @return True, if target server gtid was reached within allotted time
|
|
*/
|
|
bool catchup_to_master(GeneralOpData& op, const GtidList& target);
|
|
|
|
/**
|
|
* Find slave connection to the target server. If the IO thread is trying to connect
|
|
* ("Connecting"), the connection is only accepted if the 'Master_Server_Id' is known to be correct.
|
|
* If the IO or the SQL thread is stopped, the connection is not returned.
|
|
*
|
|
* @param target Immediate master or relay server
|
|
* @return The slave status info of the slave thread, or NULL if not found or not accepted
|
|
*/
|
|
const SlaveStatus* slave_connection_status(const MariaDBServer* target) const;
|
|
|
|
/**
|
|
* Find slave connection to the target server. Only considers host and port when selecting
|
|
* the connection. A matching connection is accepted even if its IO or SQL thread is stopped.
|
|
*
|
|
* @param target Immediate master or relay server
|
|
* @return The slave status info of the slave thread, or NULL if not found
|
|
*/
|
|
const SlaveStatus* slave_connection_status_host_port(const MariaDBServer* target) const;
|
|
|
|
/**
|
|
* Checks if this server can replicate from master. Only considers gtid:s and only detects obvious
|
|
* errors. The non-detected errors will mostly be detected once the slave tries to start replicating.
|
|
* Before calling this, update the gtid:s of the master so that the the gtid:s of the master are more
|
|
* recent than those of this server.
|
|
*
|
|
* @param master_info Master server
|
|
* @param reason_out Details the reason for a negative result
|
|
* @return True if slave can replicate from master
|
|
*/
|
|
bool can_replicate_from(MariaDBServer* master, std::string* reason_out);
|
|
|
|
/**
|
|
* Redirect one slave server to another master
|
|
*
|
|
* @param change_cmd Change master command, usually generated by generate_change_master_cmd()
|
|
* @return True if slave accepted all commands
|
|
*/
|
|
bool redirect_one_slave(const std::string& change_cmd);
|
|
|
|
/**
|
|
* Check if the server can be demoted by switchover.
|
|
*
|
|
* @param reason_out Output explaining why server cannot be demoted
|
|
* @return True if server can be demoted
|
|
*/
|
|
bool can_be_demoted_switchover(std::string* reason_out);
|
|
|
|
/**
|
|
* Check if the server can be demoted by failover.
|
|
*
|
|
* @param operation Switchover or failover
|
|
* @param reason_out Output explaining why server cannot be demoted
|
|
* @return True if server can be demoted
|
|
*/
|
|
bool can_be_demoted_failover(std::string* reason_out);
|
|
|
|
/**
|
|
* Check if the server can be promoted by switchover or failover.
|
|
*
|
|
* @param op Switchover or failover
|
|
* @param demotion_target The server this should be promoted to
|
|
* @param reason_out Output for the reason server cannot be promoted
|
|
* @return True, if suggested new master is a viable promotion candidate
|
|
*/
|
|
bool can_be_promoted(OperationType op, const MariaDBServer* demotion_target, std::string* reason_out);
|
|
|
|
/**
|
|
* Read the file contents and send them as sql queries to the server. Any data
|
|
* returned by the queries is discarded.
|
|
*
|
|
* @param server Server to send queries to
|
|
* @param path Text file path.
|
|
* @param error_out Error output
|
|
* @return True if file was read and all commands were completed successfully
|
|
*/
|
|
bool run_sql_from_file(const std::string& path, json_t** error_out);
|
|
|
|
/**
|
|
* Enable any "SLAVESIDE_DISABLED" events. Event scheduler is not touched.
|
|
*
|
|
* @param error_out Error output
|
|
* @return True if all SLAVESIDE_DISABLED events were enabled
|
|
*/
|
|
bool enable_events(json_t** error_out);
|
|
|
|
/**
|
|
* Disable any "ENABLED" events. Event scheduler is not touched.
|
|
*
|
|
* @param binlog_mode If OFF, binlog event creation is disabled for the session during method execution.
|
|
* @param error_out Error output
|
|
* @return True if all ENABLED events were disabled
|
|
*/
|
|
bool disable_events(BinlogMode binlog_mode, json_t** error_out);
|
|
|
|
/**
|
|
* Stop and delete all slave connections.
|
|
*
|
|
* @param error_out Error output
|
|
* @return True if successful. If false, some connections may have been successfully deleted.
|
|
*/
|
|
bool reset_all_slave_conns(json_t** error_out);
|
|
|
|
/**
|
|
* Promote this server to take role of demotion target. Remove slave connections from this server.
|
|
* If target is/was a master, set read-only to OFF. Copy slave connections from target.
|
|
*
|
|
* @param op Cluster operation descriptor
|
|
* @return True if successful
|
|
*/
|
|
bool promote(GeneralOpData& op, ServerOperation& promotion, OperationType type,
|
|
const MariaDBServer* demotion_target);
|
|
|
|
/**
|
|
* Demote this server. Removes all slave connections. If server was master, sets read_only.
|
|
*
|
|
* @param op Cluster operation descriptor
|
|
* @return True if successful
|
|
*/
|
|
bool demote(GeneralOpData& general, ServerOperation& op);
|
|
|
|
/**
|
|
* Redirect the slave connection going to old master to replicate from new master.
|
|
*
|
|
* @param op Operation descriptor
|
|
* @param old_conn The connection which is redirected
|
|
* @param new_master The new master for the redirected connection
|
|
* @return True on success
|
|
*/
|
|
bool redirect_existing_slave_conn(GeneralOpData& op, const SlaveStatus& old_conn,
|
|
const MariaDBServer* new_master);
|
|
|
|
/**
|
|
* Copy slave connections to this server. This is usually needed during switchover promotion and on
|
|
* the demoted server. It is assumed that all slave connections of this server have
|
|
* been stopped & removed so there will be no conflicts with existing connections.
|
|
* A special rule is applied to a connection which points to this server itself: that connection
|
|
* is directed towards the 'replacement'. This is required to properly handle connections between
|
|
* the promotion and demotion targets.
|
|
*
|
|
* @param op Operation descriptor
|
|
* @params conns_to_copy The connections to add to the server
|
|
* @params replacement Which server should rep
|
|
* @return True on success
|
|
*/
|
|
bool copy_slave_conns(GeneralOpData& op, const SlaveStatusArray& conns_to_copy,
|
|
const MariaDBServer* replacement);
|
|
|
|
/**
|
|
* Create a new slave connection on the server and start it.
|
|
*
|
|
* @param op Operation descriptor
|
|
* @param slave_conn Existing connection to emulate
|
|
* @return True on success
|
|
*/
|
|
bool create_start_slave(GeneralOpData& op, const SlaveStatus& slave_conn);
|
|
|
|
/**
|
|
* Is binary log on? 'update_replication_settings' should be ran before this function to query the data.
|
|
*
|
|
* @return True if server has binary log enabled
|
|
*/
|
|
bool binlog_on() const;
|
|
|
|
/**
|
|
* Check if server is a running master.
|
|
*
|
|
* @return True if server is a master
|
|
*/
|
|
bool is_master() const;
|
|
|
|
/**
|
|
* Check if server is a running slave.
|
|
*
|
|
* @return True if server is a slave
|
|
*/
|
|
bool is_slave() const;
|
|
|
|
/**
|
|
* Check if server is a slave of an external server.
|
|
*
|
|
* @return True if server is a slave of an external server
|
|
*/
|
|
bool is_slave_of_ext_master() const;
|
|
|
|
/**
|
|
* Check if server is running and not in maintenance.
|
|
*
|
|
* @return True if server is usable
|
|
*/
|
|
bool is_usable() const;
|
|
|
|
/**
|
|
* Check if server is running.
|
|
*
|
|
* @return True if server is running
|
|
*/
|
|
bool is_running() const;
|
|
|
|
/**
|
|
* Check if server is down.
|
|
*
|
|
* @return True if server is down
|
|
*/
|
|
bool is_down() const;
|
|
|
|
/**
|
|
* Check if server is in maintenance.
|
|
*/
|
|
bool is_in_maintenance() const;
|
|
|
|
/**
|
|
* Is the server a relay master.
|
|
*/
|
|
bool is_relay_master() const;
|
|
|
|
/**
|
|
* Is the server low on disk space?
|
|
*/
|
|
bool is_low_on_disk_space() const;
|
|
|
|
/**
|
|
* Check if server has the given bits on in 'pending_status'.
|
|
*
|
|
* @param bits Bits to check
|
|
* @return True if all given bits are on
|
|
*/
|
|
bool has_status(uint64_t bits) const;
|
|
|
|
/**
|
|
* Check if server has the given bits on in 'mon_prev_status'.
|
|
*
|
|
* @param bits Bits to check
|
|
* @return True if all given bits are on
|
|
*/
|
|
bool had_status(uint64_t bits) const;
|
|
|
|
/**
|
|
* Getter for m_read_only.
|
|
*
|
|
* @return True if server is in read_only mode
|
|
*/
|
|
bool is_read_only() const;
|
|
|
|
/**
|
|
* Returns the server name.
|
|
*
|
|
* @return Server unique name
|
|
*/
|
|
const char* name() const;
|
|
|
|
/**
|
|
* Clear server pending status flags.
|
|
*
|
|
* @param bits Which flags to clear
|
|
*/
|
|
void clear_status(uint64_t bits);
|
|
|
|
/**
|
|
* Set server pending status flags.
|
|
*
|
|
* @param bits Which flags to set
|
|
*/
|
|
void set_status(uint64_t bits);
|
|
|
|
private:
|
|
class EventInfo;
|
|
typedef std::function<void (const EventInfo&, json_t** error_out)> ManipulatorFunc;
|
|
|
|
enum class StopMode
|
|
{
|
|
STOP_ONLY,
|
|
RESET,
|
|
RESET_ALL
|
|
};
|
|
enum class QueryRetryMode
|
|
{
|
|
ENABLED,
|
|
DISABLED
|
|
};
|
|
enum class ReadOnlySetting
|
|
{
|
|
ENABLE,
|
|
DISABLE
|
|
};
|
|
|
|
bool update_slave_status(std::string* errmsg_out = NULL);
|
|
bool sstatus_array_topology_equal(const SlaveStatusArray& new_slave_status);
|
|
const SlaveStatus* sstatus_find_previous_row(const SlaveStatus& new_row, size_t guess);
|
|
|
|
void warn_event_scheduler();
|
|
bool events_foreach(ManipulatorFunc& func, json_t** error_out);
|
|
bool alter_event(const EventInfo& event, const std::string& target_status,
|
|
json_t** error_out);
|
|
|
|
bool stop_slave_conn(const std::string& conn_name, StopMode mode, maxbase::Duration time_limit,
|
|
json_t** error_out);
|
|
|
|
bool remove_slave_conns(GeneralOpData& op, const SlaveStatusArray& conns_to_remove);
|
|
bool execute_cmd_ex(const std::string& cmd, QueryRetryMode mode,
|
|
std::string* errmsg_out = NULL, unsigned int* errno_out = NULL);
|
|
|
|
bool execute_cmd_time_limit(const std::string& cmd, maxbase::Duration time_limit,
|
|
std::string* errmsg_out);
|
|
|
|
bool set_read_only(ReadOnlySetting value, maxbase::Duration time_limit, json_t** error_out);
|
|
bool merge_slave_conns(GeneralOpData& op, const SlaveStatusArray& conns_to_merge);
|
|
std::string generate_change_master_cmd(GeneralOpData& op, const SlaveStatus& slave_conn);
|
|
};
|