Add support for syncing 'mysql-variables' and 'admin-variables' #2820

include/ProxySQL_Cluster.hpp

@@ -114,6 +114,8 @@ class ProxySQL_Cluster_Nodes {
 	void get_peer_to_sync_mysql_query_rules(char **host, uint16_t *port);
 	void get_peer_to_sync_mysql_servers(char **host, uint16_t *port, char **peer_checksum);
 	void get_peer_to_sync_mysql_users(char **host, uint16_t *port);
+	void get_peer_to_sync_mysql_variables(char **host, uint16_t *port);
+	void get_peer_to_sync_admin_variables(char **host, uint16_t* port);
 	void get_peer_to_sync_proxysql_servers(char **host, uint16_t *port);
 };
 
@@ -141,15 +143,25 @@ struct p_cluster_counter {
 		pulled_proxysql_servers_success,
 		pulled_proxysql_servers_failure,
 
+		pulled_mysql_variables_success,
+		pulled_mysql_variables_failure,
+
+		pulled_admin_variables_success,
+		pulled_admin_variables_failure,
+
 		sync_conflict_mysql_query_rules_share_epoch,
 		sync_conflict_mysql_servers_share_epoch,
 		sync_conflict_proxysql_servers_share_epoch,
 		sync_conflict_mysql_users_share_epoch,
+		sync_conflict_mysql_variables_share_epoch,
+		sync_conflict_admin_variables_share_epoch,
 
 		sync_delayed_mysql_query_rules_version_one,
 		sync_delayed_mysql_servers_version_one,
 		sync_delayed_mysql_users_version_one,
 		sync_delayed_proxysql_servers_version_one,
+		sync_delayed_mysql_variables_version_one,
+		sync_delayed_admin_variables_version_one,
 
 		__size
 	};
@@ -168,6 +180,14 @@ struct cluster_metrics_map_idx {
 	};
 };
 
+struct variable_type {
+	enum type {
+		mysql,
+		admin,
+		__size
+	};
+};
+
 /**
  * @brief Simple struct for holding a query, and three messages to report
  *  the progress of the query execution.
@@ -196,6 +216,7 @@ class ProxySQL_Cluster {
 	pthread_mutex_t update_mysql_query_rules_mutex;
 	pthread_mutex_t update_mysql_servers_mutex;
 	pthread_mutex_t update_mysql_users_mutex;
+	pthread_mutex_t update_mysql_variables_mutex;
 	pthread_mutex_t update_proxysql_servers_mutex;
 	int cluster_check_interval_ms;
 	int cluster_check_status_frequency;
@@ -244,6 +265,14 @@ class ProxySQL_Cluster {
 	void pull_mysql_query_rules_from_peer();
 	void pull_mysql_servers_from_peer();
 	void pull_mysql_users_from_peer();
+	/**
+	 * @brief Pulls from peer the specified global variables by the type parameter.
+	 * @param type A string specifying the type of global variables to pull from the peer, supported
+	 *  values right now are:
+	 *    - 'mysql'.
+     *    - 'admin'.
+	 */
+	void pull_global_variables_from_peer(const std::string& type);
 	void pull_proxysql_servers_from_peer();
 };
 #endif /* CLASS_PROXYSQL_CLUSTER_H */

include/proxysql_admin.h

@@ -305,6 +305,11 @@ class ProxySQL_Admin {
 	void flush_mysql_query_rules__from_disk_to_memory();
 	void flush_mysql_firewall__from_memory_to_disk();
 	void flush_mysql_firewall__from_disk_to_memory();
+	void flush_mysql_variables__from_disk_to_memory();
+	void flush_mysql_variables__from_memory_to_disk();
+	void flush_admin_variables__from_disk_to_memory();
+	void flush_admin_variables__from_memory_to_disk();
+
 	void load_mysql_servers_to_runtime();
 	void save_mysql_servers_from_runtime();
 	char * load_mysql_query_rules_to_runtime();

lib/ProxySQL_Admin.cpp

@@ -3180,6 +3180,7 @@ bool ProxySQL_Admin::GenericRefreshStatistics(const char *query_no_space, unsign
 
 		if (admin) {
 			if (dump_global_variables) {
+				pthread_mutex_lock(&GloVars.checksum_mutex);
 				admindb->execute("DELETE FROM runtime_global_variables");	// extra
 				flush_admin_variables___runtime_to_database(admindb, false, false, false, true);
 				flush_mysql_variables___runtime_to_database(admindb, false, false, false, true);
@@ -3188,6 +3189,7 @@ bool ProxySQL_Admin::GenericRefreshStatistics(const char *query_no_space, unsign
 #endif /* PROXYSQLCLICKHOUSE */
 				flush_sqliteserver_variables___runtime_to_database(admindb, false, false, false, true);
 				flush_ldap_variables___runtime_to_database(admindb, false, false, false, true);
+				pthread_mutex_unlock(&GloVars.checksum_mutex);
 			}
 			if (runtime_mysql_servers) {
 				int old_hostgroup_manager_verbose = mysql_thread___hostgroup_manager_verbose;
@@ -6009,7 +6011,7 @@ void ProxySQL_Admin::flush_mysql_variables___database_to_runtime(SQLite3DB *db,
 			int cols=0;
 			int affected_rows=0;
 			SQLite3_result *resultset=NULL;
-			char *q=(char *)"SELECT variable_name, variable_value FROM runtime_global_variables WHERE variable_name LIKE 'mysql-\%' ORDER BY variable_name";
+			char *q=(char *)"SELECT variable_name, variable_value FROM runtime_global_variables WHERE variable_name LIKE 'mysql-%' ORDER BY variable_name";
 			admindb->execute_statement(q, &error , &cols , &affected_rows , &resultset);
 			uint64_t hash1 = resultset->raw_checksum();
 			uint32_t d32[2];
@@ -9455,6 +9457,38 @@ void ProxySQL_Admin::flush_mysql_query_rules__from_memory_to_disk() {
 	admindb->wrunlock();
 }
 
+void ProxySQL_Admin::flush_mysql_variables__from_disk_to_memory() {
+	admindb->wrlock();
+	admindb->execute("PRAGMA foreign_keys = OFF");
+	admindb->execute("INSERT OR REPLACE INTO main.global_variables SELECT * FROM disk.global_variables WHERE variable_name LIKE 'mysql-%'");
+	admindb->execute("PRAGMA foreign_keys = ON");
+	admindb->wrunlock();
+}
+
+void ProxySQL_Admin::flush_mysql_variables__from_memory_to_disk() {
+	admindb->wrlock();
+	admindb->execute("PRAGMA foreign_keys = OFF");
+	admindb->execute("INSERT OR REPLACE INTO disk.global_variables SELECT * FROM main.global_variables WHERE variable_name LIKE 'mysql-%'");
+	admindb->execute("PRAGMA foreign_keys = ON");
+	admindb->wrunlock();
+}
+
+void ProxySQL_Admin::flush_admin_variables__from_disk_to_memory() {
+	admindb->wrlock();
+	admindb->execute("PRAGMA foreign_keys = OFF");
+	admindb->execute("INSERT OR REPLACE INTO main.global_variables SELECT * FROM disk.global_variables WHERE variable_name LIKE 'admin-%'");
+	admindb->execute("PRAGMA foreign_keys = ON");
+	admindb->wrunlock();
+}
+
+void ProxySQL_Admin::flush_admin_variables__from_memory_to_disk() {
+	admindb->wrlock();
+	admindb->execute("PRAGMA foreign_keys = OFF");
+	admindb->execute("INSERT OR REPLACE INTO disk.global_variables SELECT * FROM main.global_variables WHERE variable_name LIKE 'admin-%'");
+	admindb->execute("PRAGMA foreign_keys = ON");
+	admindb->wrunlock();
+}
+
 void ProxySQL_Admin::__attach_db(SQLite3DB *db1, SQLite3DB *db2, char *alias) {
 	const char *a="ATTACH DATABASE '%s' AS %s";
 	int l=strlen(a)+strlen(db2->get_url())+strlen(alias)+5;