feat: add 'replication_lag' support for PostgreSQL monitoring

include/PgSQL_Monitor.hpp

@@ -16,6 +16,8 @@
 
 #define MONITOR_SQLITE_TABLE_PGSQL_SERVER_READ_ONLY_LOG "CREATE TABLE pgsql_server_read_only_log ( hostname VARCHAR NOT NULL , port INT NOT NULL DEFAULT 3306 , time_start_us INT NOT NULL DEFAULT 0 , success_time_us INT DEFAULT 0 , read_only INT DEFAULT 1 , error VARCHAR , PRIMARY KEY (hostname, port, time_start_us))"
 
+#define MONITOR_SQLITE_TABLE_PGSQL_SERVER_REPLICATION_LAG_LOG "CREATE TABLE pgsql_server_replication_lag_log ( hostname VARCHAR NOT NULL , port INT NOT NULL DEFAULT 3306 , time_start_us INT NOT NULL DEFAULT 0 , success_time_us INT DEFAULT 0 , repl_lag INT DEFAULT 0 , error VARCHAR , PRIMARY KEY (hostname, port, time_start_us))"
+
 #define MONITOR_SQLITE_TABLE_PGSQL_SERVERS "CREATE TABLE pgsql_servers (hostname VARCHAR NOT NULL , port INT NOT NULL DEFAULT 3306 , status INT CHECK (status IN (0, 1, 2, 3, 4)) NOT NULL DEFAULT 0 , use_ssl INT CHECK (use_ssl IN(0,1)) NOT NULL DEFAULT 0 , PRIMARY KEY (hostname, port) )"
 
 #define MONITOR_SQLITE_TABLE_PROXYSQL_SERVERS "CREATE TABLE proxysql_servers (hostname VARCHAR NOT NULL , port INT NOT NULL DEFAULT 6032 , weight INT CHECK (weight >= 0) NOT NULL DEFAULT 0 , comment VARCHAR NOT NULL DEFAULT '' , PRIMARY KEY (hostname, port) )"
@@ -39,6 +41,8 @@
 	uint64_t ping_check_OK { 0 };
 	uint64_t readonly_check_ERR { 0 };
 	uint64_t readonly_check_OK { 0 };
+	uint64_t repl_lag_check_ERR { 0 };
+	uint64_t repl_lag_check_OK { 0 };
 	uint64_t ssl_connections_OK { 0 };
 	uint64_t non_ssl_connections_OK { 0 };
 	///////////////////////////////////////////////////////////////////////////
@@ -56,6 +60,10 @@
 			const_cast<char*>("pgsql_server_read_only_log"),
 			const_cast<char*>(MONITOR_SQLITE_TABLE_PGSQL_SERVER_READ_ONLY_LOG)
 		},
+		{
+			const_cast<char*>("pgsql_server_replication_lag_log"),
+			const_cast<char*>(MONITOR_SQLITE_TABLE_PGSQL_SERVER_REPLICATION_LAG_LOG)
+		},
 	};
 
 	std::vector<table_def_t> tables_defs_monitor_internal {

include/PgSQL_Thread.h

@@ -904,6 +904,7 @@ class PgSQL_Threads_Handler
 		bool monitor_replication_lag_group_by_host;
 		//! How frequently a replication lag check is performed. Unit: 'ms'.
 		int monitor_replication_lag_interval;
+		int monitor_replication_lag_interval_window;
 		//! Read only check timeout. Unit: 'ms'.
 		int monitor_replication_lag_timeout;
 		int monitor_replication_lag_count;

include/proxysql_structs.h

@@ -749,6 +749,7 @@ enum PROXYSQL_MYSQL_ERR {
 	ER_PROXYSQL_CONNECT_TIMEOUT                       = 9020,
 	ER_PROXYSQL_READONLY_TIMEOUT                      = 9021,
 	ER_PROXYSQL_FAST_FORWARD_CONN_CREATE              = 9022,
+	ER_PROXYSQL_REPL_LAG_TIMEOUT                      = 9023,
 };
 
 enum proxysql_session_type {
@@ -1205,6 +1206,11 @@ __thread int pgsql_thread___monitor_read_only_interval;
 __thread int pgsql_thread___monitor_read_only_interval_window;
 __thread int pgsql_thread___monitor_read_only_timeout;
 __thread int pgsql_thread___monitor_read_only_max_timeout_count;
+__thread int pgsql_thread___monitor_replication_lag_interval;
+__thread int pgsql_thread___monitor_replication_lag_interval_window;
+__thread int pgsql_thread___monitor_replication_lag_timeout;
+__thread int pgsql_thread___monitor_replication_lag_count;
+__thread char* pgsql_thread___monitor_replication_lag_use_percona_heartbeat;
 __thread bool pgsql_thread___monitor_writer_is_also_reader;
 __thread int pgsql_thread___monitor_threads;
 __thread char* pgsql_thread___monitor_username;
@@ -1527,6 +1533,11 @@ extern __thread int pgsql_thread___monitor_ping_timeout;
 extern __thread int pgsql_thread___monitor_read_only_interval;
 extern __thread int pgsql_thread___monitor_read_only_interval_window;
 extern __thread int pgsql_thread___monitor_read_only_timeout;
+extern __thread int pgsql_thread___monitor_replication_lag_interval;
+extern __thread int pgsql_thread___monitor_replication_lag_interval_window;
+extern __thread int pgsql_thread___monitor_replication_lag_timeout;
+extern __thread int pgsql_thread___monitor_replication_lag_count;
+extern __thread char* pgsql_thread___monitor_replication_lag_use_percona_heartbeat;
 extern __thread int pgsql_thread___monitor_read_only_max_timeout_count;
 extern __thread bool pgsql_thread___monitor_writer_is_also_reader;
 extern __thread int pgsql_thread___monitor_threads;

lib/PgSQL_HostGroups_Manager.cpp

@@ -2667,7 +2667,7 @@ void PgSQL_HostGroups_Manager::replication_lag_action_inner(PgSQL_HGC *myhgc, co
 				) {
 					// always increase the counter
 					mysrvc->cur_replication_lag_count += 1;
-					if (mysrvc->cur_replication_lag_count >= (unsigned int)mysql_thread___monitor_replication_lag_count) {
+					if (mysrvc->cur_replication_lag_count >= (unsigned int)pgsql_thread___monitor_replication_lag_count) {
 						proxy_warning("Shunning server %s:%d from HG %u with replication lag of %d second, count number: '%d'\n", address, port, myhgc->hid, current_replication_lag, mysrvc->cur_replication_lag_count);
 						mysrvc->status=MYSQL_SERVER_STATUS_SHUNNED_REPLICATION_LAG;
 					} else {
@@ -2678,7 +2678,7 @@ void PgSQL_HostGroups_Manager::replication_lag_action_inner(PgSQL_HGC *myhgc, co
 							myhgc->hid,
 							current_replication_lag,
 							mysrvc->cur_replication_lag_count,
-							mysql_thread___monitor_replication_lag_count
+							pgsql_thread___monitor_replication_lag_count
 						);
 					}
 				} else {
@@ -2716,7 +2716,7 @@ void PgSQL_HostGroups_Manager::replication_lag_action(const std::list<replicatio
 		const unsigned int port = std::get<PgSQL_REPLICATION_LAG_SERVER_T::PG_RLS_PORT>(server);
 		const int current_replication_lag = std::get<PgSQL_REPLICATION_LAG_SERVER_T::PG_RLS_CURRENT_REPLICATION_LAG>(server);
 
-		if (mysql_thread___monitor_replication_lag_group_by_host == false) {
+		if (/* pgsql_thread___monitor_replication_lag_group_by_host == */ false) { // feature currently not enabled
 			// legacy check. 1 check per server per hostgroup
 			PgSQL_HGC *myhgc = MyHGC_find(hid);
 			replication_lag_action_inner(myhgc,address.c_str(),port,current_replication_lag);