[#2734] tcp_user_timeout for PostgreSQL 12+

Added conditional compilation to set tcp_user_timeout parameter for the
PostgreSQL 12 or later. Log a warning for earlier PostgreSQL versions.

configure.ac

@@ -802,6 +802,7 @@ if test "$PG_CONFIG" != "" ; then
     PGSQL_LIBS=`$PG_CONFIG --libdir`
     PGSQL_LIBS="-L$PGSQL_LIBS -lpq"
     PGSQL_VERSION=`$PG_CONFIG --version`
+    PGSQL_MAJOR_VERSION=`$PG_CONFIG --version | cut -f2 -d' ' | cut -f1 -d'.'`
 
     AC_SUBST(PGSQL_CPPFLAGS)
     AC_SUBST(PGSQL_LIBS)
@@ -831,6 +832,10 @@ if test "$PG_CONFIG" != "" ; then
 
     # Note that PostgreSQL is present in the config.h file
     AC_DEFINE([HAVE_PGSQL], [1], [PostgreSQL is present])
+
+if test $PGSQL_MAJOR_VERSION -ge 12; then
+   AC_DEFINE([HAVE_PGSQL_TCP_USER_TIMEOUT], [1], [PostgreSQL connection parameter tcp_user_timeout supported])
+fi
 fi
 
 # ... and at the shell level, so Makefile.am can take action depending on this.

src/lib/database/db_log.cc

@@ -1,4 +1,4 @@
-// Copyright (C) 2018-2022 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2018-2023 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -31,6 +31,7 @@ const DbLogger::MessageMap db_message_map = {
     { PGSQL_ROLLBACK,                     DATABASE_PGSQL_ROLLBACK },
     { PGSQL_CREATE_SAVEPOINT,             DATABASE_PGSQL_CREATE_SAVEPOINT },
     { PGSQL_ROLLBACK_SAVEPOINT,           DATABASE_PGSQL_ROLLBACK_SAVEPOINT },
+    { PGSQL_TCP_USER_TIMEOUT_UNSUPPORTED, DATABASE_PGSQL_TCP_USER_TIMEOUT_UNSUPPORTED },
 
     { MYSQL_FATAL_ERROR,                  DATABASE_MYSQL_FATAL_ERROR },
     { MYSQL_START_TRANSACTION,            DATABASE_MYSQL_START_TRANSACTION },

src/lib/database/db_log.h

@@ -1,4 +1,4 @@
-// Copyright (C) 2018-2022 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2018-2023 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -58,6 +58,7 @@ enum DbMessageID {
     PGSQL_ROLLBACK,
     PGSQL_CREATE_SAVEPOINT,
     PGSQL_ROLLBACK_SAVEPOINT,
+    PGSQL_TCP_USER_TIMEOUT_UNSUPPORTED,
 
     MYSQL_FATAL_ERROR,
     MYSQL_START_TRANSACTION,

src/lib/database/db_messages.mes

@@ -80,6 +80,12 @@ inserted into multiple tables with multiple INSERT statements
 and there may be a need to rollback the whole transaction if
 any of these INSERT statements fail.
 
+% DATABASE_PGSQL_TCP_USER_TIMEOUT_UNSUPPORTED tcp_user_timeout is not supported in this PostgreSQL version
+This warning message is issued when a user has configured the tcp_user_timeout
+parameter in the connection to the PostgreSQL database but the installed database
+does not support this parameter. This parameter is supported by the PostgreSQL
+version 12 or later. The parameter setting will be ignored.
+
 % DATABASE_TO_JSON_BOOLEAN_ERROR Internal logic error: invalid boolean value found in database connection parameters: %1=%2
 This error message is printed when conversion to JSON of the internal state is requested,
 but the connection string contains a boolean parameter with invalid value. It is a programming

src/lib/pgsql/pgsql_connection.cc

@@ -249,11 +249,17 @@ PgSqlConnection::getConnParameters() {
         isc_throw(DbInvalidTimeout, ex.what());
     }
 
-    // Append timeouts.
+    // Append connection timeout.
     std::ostringstream oss;
     oss << " connect_timeout = " << connect_timeout;
+
     if (tcp_user_timeout > 0) {
+// tcp_user_timeout parameter is a PostgreSQL 12+ feature.
+#ifdef HAVE_PGSQL_TCP_USER_TIMEOUT
         oss << " tcp_user_timeout = " << tcp_user_timeout * 1000;
+#else
+        DB_LOG_WARN(PGSQL_TCP_USER_TIMEOUT_UNSUPPORTED).arg();
+#endif
     }
     dbconnparameters += oss.str();
 

src/lib/pgsql/tests/pgsql_connection_unittest.cc

@@ -611,7 +611,9 @@ TEST_F(PgSqlConnectionTest, connectionTimeoutInvalid3) {
     EXPECT_THROW(conn.getConnParameters(), DbInvalidTimeout);
 }
 
-// Tests that valid tcp user timeout is accepted.
+// Tests that valid tcp user timeout is accepted. This parameter is
+// supported by PostgreSQL 12 and later.
+#ifdef HAVE_PGSQL_TCP_USER_TIMEOUT
 TEST_F(PgSqlConnectionTest, tcpUserTimeout) {
     std::string conn_str = connectionString(PGSQL_VALID_TYPE, VALID_NAME,
                                             VALID_USER, VALID_PASSWORD,
@@ -622,6 +624,7 @@ TEST_F(PgSqlConnectionTest, tcpUserTimeout) {
     EXPECT_TRUE(parameters.find("tcp_user_timeout = 8000") != std::string::npos)
         << "parameter not found in " << parameters;
 }
+#endif
 
 // Tests that a zero tcp user timeout is accepted.
 TEST_F(PgSqlConnectionTest, tcpUserTimeoutZero) {