MXS-1507: Test transaction replay with switchover

Added a test case that verifies that a successful transaction replay is
performed when a master switchover is performed.

maxscale-system-test/CMakeLists.txt

@@ -621,6 +621,10 @@ add_test_executable(mxs1507_trx_replay.cpp mxs1507_trx_replay mxs1507_trx_replay
 # https://jira.mariadb.org/browse/MXS-1507
 add_test_executable(mxs1507_inconsistent_trx.cpp mxs1507_inconsistent_trx mxs1507_trx_replay LABELS readwritesplit REPL_BACKEND)
 
+# MXS-1507: Transaction migration
+# https://jira.mariadb.org/browse/MXS-1507
+add_test_executable(mxs1507_migrate_trx.cpp mxs1507_migrate_trx mxs1507_trx_replay LABELS readwritesplit REPL_BACKEND)
+
 # MXS-1509: Show correct server state for multisource replication
 # https://jira.mariadb.org/browse/MXS-1509
 add_test_executable(mxs1509.cpp mxs1509 mxs1509 LABELS mysqlmon REPL_BACKEND)

maxscale-system-test/mxs1507_migrate_trx.cpp

@@ -0,0 +1,90 @@
+/**
+ * MXS-1507: Test migration of transactions
+ *
+ * https://jira.mariadb.org/browse/MXS-1507
+ */
+#include "testconnections.h"
+#include <functional>
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+int main(int argc, char** argv)
+{
+    Mariadb_nodes::require_gtid(true);
+    TestConnections test(argc, argv);
+    string master = "server1";
+    string slave = "server2";
+
+    auto switchover = [&]()
+    {
+        test.maxscales->ssh_node_f(0, true, "maxctrl call command mariadbmon switchover MySQL-Monitor %s %s",
+                                   master.c_str(), slave.c_str());
+        master.swap(slave);
+        sleep(5); // Seems that the system needs a few seconds to stabilize
+    };
+
+    auto query = [&](string q)
+    {
+        return execute_query_silent(test.maxscales->conn_rwsplit[0], q.c_str()) == 0;
+    };
+
+    auto ok = [&](string q)
+    {
+        test.assert(query(q), "Query '%s' should work: %s", q.c_str(), mysql_error(test.maxscales->conn_rwsplit[0]));
+    };
+
+    auto check = [&](string q)
+    {
+        ok("START TRANSACTION");
+        Row row = get_row(test.maxscales->conn_rwsplit[0], q.c_str());
+        ok("COMMIT");
+        test.assert(!row.empty() && row[0] == "1", "Query should return 1: %s", q.c_str());
+    };
+
+    // Create a table, insert a value and make sure it's replicated to all slaves
+    test.maxscales->connect();
+    ok("CREATE OR REPLACE TABLE test.t1 (id INT)");
+    ok("INSERT INTO test.t1 VALUES (1)");
+    test.repl->connect();
+    test.repl->sync_slaves();
+    test.maxscales->disconnect();
+
+    cout << "Commit transaction" << endl;
+    test.maxscales->connect();
+    ok("START TRANSACTION");
+    ok("SELECT id FROM test.t1 WHERE id = 1 FOR UPDATE");
+    switchover();
+    ok("UPDATE test.t1 SET id = 2 WHERE id = 1");
+    ok("COMMIT");
+    check("SELECT COUNT(*) = 1 FROM t1 WHERE id = 2");
+
+    test.maxscales->disconnect();
+
+    cout << "Rollback transaction" << endl;
+    test.maxscales->connect();
+    ok("START TRANSACTION");
+    ok("UPDATE test.t1 SET id = 1");
+    switchover();
+    ok("ROLLBACK");
+    check("SELECT COUNT(*) = 1 FROM t1 WHERE id = 2");
+    test.maxscales->disconnect();
+
+    cout << "Read-only transaction" << endl;
+    test.maxscales->connect();
+    ok("START TRANSACTION READ ONLY");
+    ok("SELECT @@server_id"); // This causes a checksum mismatch if the transaction is migrated
+    switchover();
+    ok("COMMIT");
+    test.maxscales->disconnect();
+
+    test.maxscales->connect();
+    ok("DROP TABLE test.t1");
+    test.maxscales->disconnect();
+
+    // Even number of switchovers should bring us back to the original master
+    switchover();
+
+    return test.global_result;
+}