fix(tests): clear MariaDB GTID slave state when repointing replicas

MariaDB relay-drain ensure_flat failed with errno 1950 (gtid strict
out-of-order) after prior local GTIDs on replicas. Disable strict mode
in test cnf, RESET + clear gtid_slave_pos on repoint, and require both
IO and SQL running in setup-replication.

Author: renecannao

tests/functional/mysql/mariadb-master.cnf

@@ -3,6 +3,6 @@ server-id=1
 log-bin=mysql-bin
 binlog-format=ROW
 log-slave-updates=ON
-gtid_strict_mode=ON
+gtid_strict_mode=OFF
 binlog-row-image=MINIMAL
 report-host=mysql1

tests/functional/mysql/mariadb-replica.cnf

@@ -3,7 +3,7 @@ server-id=2
 log-bin=mysql-bin
 binlog-format=ROW
 log-slave-updates=ON
-gtid_strict_mode=ON
+gtid_strict_mode=OFF
 binlog-row-image=MINIMAL
 read_only=ON
 report-host=mysql2

tests/functional/mysql/mariadb-replica2.cnf

@@ -3,7 +3,7 @@ server-id=3
 log-bin=mysql-bin
 binlog-format=ROW
 log-slave-updates=ON
-gtid_strict_mode=ON
+gtid_strict_mode=OFF
 binlog-row-image=MINIMAL
 read_only=ON
 report-host=mysql3

tests/functional/setup-replication.sh

@@ -40,10 +40,12 @@ echo "Verifying replication..."
 for REPLICA in mysql2 mysql3; do
     for i in $(seq 1 60); do
         if echo "$MYSQL_FULL_VERSION" | grep -qi mariadb; then
-            STATUS=$($COMPOSE exec -T "$REPLICA" mysql -uroot -ptestpass -e \
-                "SHOW SLAVE STATUS\G" 2>/dev/null | awk '/Slave_IO_Running:/{print $2; exit}' | tr -d '[:space:]')
-            if [ "$STATUS" = "Yes" ]; then
-                echo "$REPLICA: replication OK (IO thread Yes)"
+            IO=$($COMPOSE exec -T "$REPLICA" mysql -uroot -ptestpass -e \
+                "SHOW SLAVE STATUS\G" 2>/dev/null | awk -F': *' '/Slave_IO_Running:/{print $2; exit}' | tr -d '[:space:]')
+            SQL=$($COMPOSE exec -T "$REPLICA" mysql -uroot -ptestpass -e \
+                "SHOW SLAVE STATUS\G" 2>/dev/null | awk -F': *' '/Slave_SQL_Running:/{print $2; exit}' | tr -d '[:space:]')
+            if [ "$IO" = "Yes" ] && [ "$SQL" = "Yes" ]; then
+                echo "$REPLICA: replication OK (IO+SQL Yes)"
                 break
             fi
         else

tests/functional/test-mariadb-relay-drain.sh

@@ -79,21 +79,17 @@ nudge_replica_threads() {
 repoint_replica_to_mysql1() {
     local r="$1"
     $COMPOSE exec -T "$r" mysql -uroot -ptestpass -e "STOP REPLICA; STOP SLAVE;" 2>/dev/null || true
-    # Skip RESET when possible — RESET wipes GTID state and often leaves SQL=No on MariaDB
-    # until positions are re-established. Prefer CHANGE + START first.
-    if ! $COMPOSE exec -T "$r" mysql -uroot -ptestpass -e "
+    # RESET drops errant/local GTID history from prior failover tests.
+    # MariaDB errno 1950: out-of-order GTID when gtid_slave_pos / strict mode conflict.
+    $COMPOSE exec -T "$r" mysql -uroot -ptestpass -e "$RESET_REPLICA" 2>/dev/null || true
+    if mysql_is_mariadb; then
+        $COMPOSE exec -T "$r" mysql -uroot -ptestpass -e "SET GLOBAL gtid_slave_pos=''; SET GLOBAL gtid_strict_mode=OFF;" 2>/dev/null || true
+    fi
+    $COMPOSE exec -T "$r" mysql -uroot -ptestpass -e "
         $CHANGE_TO_MYSQL1
         SET GLOBAL read_only=1;
         $START_REPLICA
-    " 2>/dev/null; then
-        $COMPOSE exec -T "$r" mysql -uroot -ptestpass -e "
-            $STOP_REPLICA
-            $RESET_REPLICA
-            $CHANGE_TO_MYSQL1
-            SET GLOBAL read_only=1;
-            $START_REPLICA
-        " 2>/dev/null || true
-    fi
+    " 2>/dev/null || true
     nudge_replica_threads "$r"
 }