Verify database connection on interval (#9665)

src/database/database-postgresql.cpp

@@ -90,13 +90,19 @@ void Database_PostgreSQL::connectToDatabase()
 	initStatements();
 }
 
-void Database_PostgreSQL::verifyDatabase()
+void Database_PostgreSQL::pingDatabase()
 {
-	if (PQstatus(m_conn) == CONNECTION_OK)
+	// Verify DB connection with ping
-		return;
+	try {
-
-	PQreset(m_conn);
 		ping();
+	} catch (const DatabaseException &e) {
+		// If ping failed, show the error and try reconnect
+		PQreset(m_conn);
+
+		errorstream << e.what() << std::endl
+			<< "Reconnecting to database " << m_connect_string << std::endl;
+		connectToDatabase();
+	}
 }
 
 void Database_PostgreSQL::ping()
@@ -151,7 +157,7 @@ void Database_PostgreSQL::createTableIfNotExists(const std::string &table_name,
 
 void Database_PostgreSQL::beginSave()
 {
-	verifyDatabase();
+	pingDatabase();
 	checkResults(PQexec(m_conn, "BEGIN;"));
 }
 
@@ -227,7 +233,7 @@ bool MapDatabasePostgreSQL::saveBlock(const v3s16 &pos, const std::string &data)
 		return false;
 	}
 
-	verifyDatabase();
+	pingDatabase();
 
 	s32 x, y, z;
 	x = htonl(pos.X);
@@ -251,7 +257,7 @@ bool MapDatabasePostgreSQL::saveBlock(const v3s16 &pos, const std::string &data)
 
 void MapDatabasePostgreSQL::loadBlock(const v3s16 &pos, std::string *block)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	s32 x, y, z;
 	x = htonl(pos.X);
@@ -275,7 +281,7 @@ void MapDatabasePostgreSQL::loadBlock(const v3s16 &pos, std::string *block)
 
 bool MapDatabasePostgreSQL::deleteBlock(const v3s16 &pos)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	s32 x, y, z;
 	x = htonl(pos.X);
@@ -293,7 +299,7 @@ bool MapDatabasePostgreSQL::deleteBlock(const v3s16 &pos)
 
 void MapDatabasePostgreSQL::listAllLoadableBlocks(std::vector<v3s16> &dst)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	PGresult *results = execPrepared("list_all_loadable_blocks", 0,
 		NULL, NULL, NULL, false, false);
@@ -435,7 +441,7 @@ void PlayerDatabasePostgreSQL::initStatements()
 
 bool PlayerDatabasePostgreSQL::playerDataExists(const std::string &playername)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	const char *values[] = { playername.c_str() };
 	PGresult *results = execPrepared("load_player", 1, values, false);
@@ -451,7 +457,7 @@ void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
 	if (!sao)
 		return;
 
-	verifyDatabase();
+	pingDatabase();
 
 	v3f pos = sao->getBasePosition();
 	std::string pitch = ftos(sao->getLookPitch());
@@ -535,7 +541,7 @@ void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
 bool PlayerDatabasePostgreSQL::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
 {
 	sanity_check(sao);
-	verifyDatabase();
+	pingDatabase();
 
 	const char *values[] = { player->getName() };
 	PGresult *results = execPrepared("load_player", 1, values, false, false);
@@ -610,7 +616,7 @@ bool PlayerDatabasePostgreSQL::removePlayer(const std::string &name)
 	if (!playerDataExists(name))
 		return false;
 
-	verifyDatabase();
+	pingDatabase();
 
 	const char *values[] = { name.c_str() };
 	execPrepared("remove_player", 1, values);
@@ -620,7 +626,7 @@ bool PlayerDatabasePostgreSQL::removePlayer(const std::string &name)
 
 void PlayerDatabasePostgreSQL::listPlayers(std::vector<std::string> &res)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	PGresult *results = execPrepared("load_player_list", 0, NULL, false);
 

src/database/database-postgresql.h

@@ -32,12 +32,13 @@ public:
 	Database_PostgreSQL(const std::string &connect_string);
 	~Database_PostgreSQL();
 
+	virtual void pingDatabase();
+
 	void beginSave();
 	void endSave();
 
 	bool initialized() const;
 
-
 protected:
 	// Conversion helpers
 	inline int pg_to_int(PGresult *res, int row, int col)
@@ -82,7 +83,6 @@ protected:
 	}
 
 	void createTableIfNotExists(const std::string &table_name, const std::string &definition);
-	void verifyDatabase();
 
 	// Database initialization
 	void connectToDatabase();
@@ -113,6 +113,8 @@ public:
 	MapDatabasePostgreSQL(const std::string &connect_string);
 	virtual ~MapDatabasePostgreSQL() = default;
 
+	virtual void pingDatabase() { Database_PostgreSQL::pingDatabase(); }
+
 	bool saveBlock(const v3s16 &pos, const std::string &data);
 	void loadBlock(const v3s16 &pos, std::string *block);
 	bool deleteBlock(const v3s16 &pos);
@@ -132,6 +134,8 @@ public:
 	PlayerDatabasePostgreSQL(const std::string &connect_string);
 	virtual ~PlayerDatabasePostgreSQL() = default;
 
+	virtual void pingDatabase() { Database_PostgreSQL::pingDatabase(); }
+
 	void savePlayer(RemotePlayer *player);
 	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao);
 	bool removePlayer(const std::string &name);

src/database/database-sqlite3.cpp

@@ -121,7 +121,7 @@ Database_SQLite3::Database_SQLite3(const std::string &savedir, const std::string
 
 void Database_SQLite3::beginSave()
 {
-	verifyDatabase();
+	pingDatabase();
 	SQLRES(sqlite3_step(m_stmt_begin), SQLITE_DONE,
 		"Failed to start SQLite3 transaction");
 	sqlite3_reset(m_stmt_begin);
@@ -129,7 +129,7 @@ void Database_SQLite3::beginSave()
 
 void Database_SQLite3::endSave()
 {
-	verifyDatabase();
+	pingDatabase();
 	SQLRES(sqlite3_step(m_stmt_end), SQLITE_DONE,
 		"Failed to commit SQLite3 transaction");
 	sqlite3_reset(m_stmt_end);
@@ -171,7 +171,7 @@ void Database_SQLite3::openDatabase()
 		"Failed to enable sqlite3 foreign key support");
 }
 
-void Database_SQLite3::verifyDatabase()
+void Database_SQLite3::pingDatabase()
 {
 	if (m_initialized) return;
 
@@ -247,7 +247,7 @@ inline void MapDatabaseSQLite3::bindPos(sqlite3_stmt *stmt, const v3s16 &pos, in
 
 bool MapDatabaseSQLite3::deleteBlock(const v3s16 &pos)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	bindPos(m_stmt_delete, pos);
 
@@ -263,7 +263,7 @@ bool MapDatabaseSQLite3::deleteBlock(const v3s16 &pos)
 
 bool MapDatabaseSQLite3::saveBlock(const v3s16 &pos, const std::string &data)
 {
-	verifyDatabase();
+	pingDatabase();
 
 #ifdef __ANDROID__
 	/**
@@ -290,7 +290,7 @@ bool MapDatabaseSQLite3::saveBlock(const v3s16 &pos, const std::string &data)
 
 void MapDatabaseSQLite3::loadBlock(const v3s16 &pos, std::string *block)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	bindPos(m_stmt_read, pos);
 
@@ -311,7 +311,7 @@ void MapDatabaseSQLite3::loadBlock(const v3s16 &pos, std::string *block)
 
 void MapDatabaseSQLite3::listAllLoadableBlocks(std::vector<v3s16> &dst)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	while (sqlite3_step(m_stmt_list) == SQLITE_ROW)
 		dst.push_back(getIntegerAsBlock(sqlite3_column_int64(m_stmt_list, 0)));
@@ -439,7 +439,7 @@ void PlayerDatabaseSQLite3::initStatements()
 
 bool PlayerDatabaseSQLite3::playerDataExists(const std::string &name)
 {
-	verifyDatabase();
+	pingDatabase();
 	str_to_sqlite(m_stmt_player_load, 1, name);
 	bool res = (sqlite3_step(m_stmt_player_load) == SQLITE_ROW);
 	sqlite3_reset(m_stmt_player_load);
@@ -536,7 +536,7 @@ void PlayerDatabaseSQLite3::savePlayer(RemotePlayer *player)
 
 bool PlayerDatabaseSQLite3::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	str_to_sqlite(m_stmt_player_load, 1, player->getName());
 	if (sqlite3_step(m_stmt_player_load) != SQLITE_ROW) {
@@ -600,7 +600,7 @@ bool PlayerDatabaseSQLite3::removePlayer(const std::string &name)
 
 void PlayerDatabaseSQLite3::listPlayers(std::vector<std::string> &res)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	while (sqlite3_step(m_stmt_player_list) == SQLITE_ROW)
 		res.push_back(sqlite_to_string(m_stmt_player_list, 0));
@@ -673,7 +673,7 @@ void AuthDatabaseSQLite3::initStatements()
 
 bool AuthDatabaseSQLite3::getAuth(const std::string &name, AuthEntry &res)
 {
-	verifyDatabase();
+	pingDatabase();
 	str_to_sqlite(m_stmt_read, 1, name);
 	if (sqlite3_step(m_stmt_read) != SQLITE_ROW) {
 		sqlite3_reset(m_stmt_read);
@@ -735,7 +735,7 @@ bool AuthDatabaseSQLite3::createAuth(AuthEntry &authEntry)
 
 bool AuthDatabaseSQLite3::deleteAuth(const std::string &name)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	str_to_sqlite(m_stmt_delete, 1, name);
 	sqlite3_vrfy(sqlite3_step(m_stmt_delete), SQLITE_DONE);
@@ -749,7 +749,7 @@ bool AuthDatabaseSQLite3::deleteAuth(const std::string &name)
 
 void AuthDatabaseSQLite3::listNames(std::vector<std::string> &res)
 {
-	verifyDatabase();
+	pingDatabase();
 
 	while (sqlite3_step(m_stmt_list_names) == SQLITE_ROW) {
 		res.push_back(sqlite_to_string(m_stmt_list_names, 0));

src/database/database-sqlite3.h

@@ -36,13 +36,13 @@ public:
 	void beginSave();
 	void endSave();
 
+	// Open and initialize the database if needed
+	virtual void pingDatabase();
+
 	bool initialized() const { return m_initialized; }
 protected:
 	Database_SQLite3(const std::string &savedir, const std::string &dbname);
 
-	// Open and initialize the database if needed
-	void verifyDatabase();
-
 	// Convertors
 	inline void str_to_sqlite(sqlite3_stmt *s, int iCol, const std::string &str) const
 	{
@@ -146,6 +146,8 @@ public:
 	MapDatabaseSQLite3(const std::string &savedir);
 	virtual ~MapDatabaseSQLite3();
 
+	virtual void pingDatabase() { Database_SQLite3::pingDatabase(); }
+
 	bool saveBlock(const v3s16 &pos, const std::string &data);
 	void loadBlock(const v3s16 &pos, std::string *block);
 	bool deleteBlock(const v3s16 &pos);
@@ -173,6 +175,8 @@ public:
 	PlayerDatabaseSQLite3(const std::string &savedir);
 	virtual ~PlayerDatabaseSQLite3();
 
+	virtual void pingDatabase() { Database_SQLite3::pingDatabase(); }
+
 	void savePlayer(RemotePlayer *player);
 	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao);
 	bool removePlayer(const std::string &name);
@@ -208,6 +212,8 @@ public:
 	AuthDatabaseSQLite3(const std::string &savedir);
 	virtual ~AuthDatabaseSQLite3();
 
+	virtual void pingDatabase() { Database_SQLite3::pingDatabase(); }
+
 	virtual bool getAuth(const std::string &name, AuthEntry &res);
 	virtual bool saveAuth(const AuthEntry &authEntry);
 	virtual bool createAuth(AuthEntry &authEntry);

src/database/database.h

@@ -32,6 +32,7 @@ public:
 	virtual void beginSave() = 0;
 	virtual void endSave() = 0;
 	virtual bool initialized() const { return true; }
+	virtual void pingDatabase() {}
 };
 
 class MapDatabase : public Database
@@ -57,6 +58,8 @@ class PlayerDatabase
 public:
 	virtual ~PlayerDatabase() = default;
 
+	virtual void pingDatabase() {}
+
 	virtual void savePlayer(RemotePlayer *player) = 0;
 	virtual bool loadPlayer(RemotePlayer *player, PlayerSAO *sao) = 0;
 	virtual bool removePlayer(const std::string &name) = 0;
@@ -83,4 +86,5 @@ public:
 	virtual bool deleteAuth(const std::string &name) = 0;
 	virtual void listNames(std::vector<std::string> &res) = 0;
 	virtual void reload() = 0;
+	virtual void pingDatabase() {}
 };

src/map.cpp

@@ -1887,6 +1887,11 @@ MapDatabase *ServerMap::createDatabase(
 	throw BaseException(std::string("Database backend ") + name + " not supported.");
 }
 
+void ServerMap::pingDatabase()
+{
+	dbase->pingDatabase();
+}
+
 void ServerMap::beginSave()
 {
 	dbase->beginSave();

src/map.h

@@ -385,6 +385,7 @@ public:
 		Database functions
 	*/
 	static MapDatabase *createDatabase(const std::string &name, const std::string &savedir, Settings &conf);
+	void pingDatabase();
 
 	// Call these before and after saving of blocks
 	void beginSave();

src/serverenvironment.cpp

@@ -1219,6 +1219,11 @@ void ServerEnvironment::step(float dtime)
 		}
 	}
 
+	if (m_database_check_interval.step(dtime, 10.0f)) {
+		m_auth_database->pingDatabase();
+		m_player_database->pingDatabase();
+		m_map->pingDatabase();
+	}
 	/*
 		Manage active block list
 	*/

src/serverenvironment.h

@@ -435,6 +435,7 @@ private:
 	IntervalLimiter m_object_management_interval;
 	// List of active blocks
 	ActiveBlockList m_active_blocks;
+	IntervalLimiter m_database_check_interval;
 	IntervalLimiter m_active_blocks_management_interval;
 	IntervalLimiter m_active_block_modifier_interval;
 	IntervalLimiter m_active_blocks_nodemetadata_interval;