Fix basictests hostgroup hook: move instead of copy to avoid monitor conflicts

Previously the hook copied servers from 1300/1301 into 0/1, leaving
both pairs active. The replication hostgroup monitor managed both
pairs simultaneously, causing race conditions that removed servers
from 0/1.

Now moves servers in-place (UPDATE) and deletes the original 1300/1301
replication entry, so only one pair (0/1) exists for the monitor.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/tap/groups/basictests/setup-infras.bash

@@ -6,8 +6,8 @@ set -o pipefail
 #
 # The in-repo infra configures servers in hostgroup pairs like 1300/1301.
 # The legacy test scripts (proxysql-tester.py benchmark) expect servers
-# in hostgroups 0 and 1. This hook copies the first hostgroup pair into
-# hostgroups 0/1 and remaps users/rules accordingly.
+# in hostgroups 0 and 1. This hook moves everything from the original
+# pair to 0/1 and removes the originals to avoid monitor conflicts.
 #
 
 export INFRA_ID="${INFRA_ID:-dev-$USER}"
@@ -15,43 +15,36 @@ PROXY_CONTAINER="proxysql.${INFRA_ID}"
 
 MYSQL_CMD="docker exec ${PROXY_CONTAINER} mysql -uradmin -pradmin -h127.0.0.1 -P6032 -NB"
 
-# Find the first writer/reader hostgroup pair from mysql_replication_hostgroups
-PAIR=$(${MYSQL_CMD} -e "SELECT writer_hostgroup, reader_hostgroup FROM mysql_replication_hostgroups LIMIT 1;" 2>/dev/null)
+# Find the first writer/reader hostgroup pair
+PAIR=$(${MYSQL_CMD} -e "SELECT writer_hostgroup, reader_hostgroup FROM mysql_replication_hostgroups WHERE writer_hostgroup != 0 LIMIT 1;" 2>/dev/null)
 if [ -z "${PAIR}" ]; then
-    echo ">>> No replication hostgroups found. Skipping hostgroup aliasing."
+    echo ">>> No non-zero replication hostgroups found. Skipping."
     exit 0
 fi
 
 WRITER_HG=$(echo "${PAIR}" | awk '{print $1}')
 READER_HG=$(echo "${PAIR}" | awk '{print $2}')
 
-if [ "${WRITER_HG}" = "0" ] && [ "${READER_HG}" = "1" ]; then
-    echo ">>> Hostgroups already 0/1. Skipping aliasing."
-    exit 0
-fi
+echo ">>> Remapping hostgroup pair ${WRITER_HG}/${READER_HG} -> 0/1"
+
+# Move servers: update hostgroup IDs in-place
+${MYSQL_CMD} -e "UPDATE mysql_servers SET hostgroup_id = 0 WHERE hostgroup_id = ${WRITER_HG};"
+${MYSQL_CMD} -e "UPDATE mysql_servers SET hostgroup_id = 1 WHERE hostgroup_id = ${READER_HG};"
 
-echo ">>> Aliasing hostgroup pair ${WRITER_HG}/${READER_HG} -> 0/1"
-
-# Copy servers from the original hostgroups into 0/1
-${MYSQL_CMD} -e "
-    INSERT OR IGNORE INTO mysql_servers (hostgroup_id, hostname, port, max_connections, comment)
-        SELECT 0, hostname, port, max_connections, comment
-        FROM mysql_servers WHERE hostgroup_id = ${WRITER_HG};
-    INSERT OR IGNORE INTO mysql_servers (hostgroup_id, hostname, port, max_connections, comment)
-        SELECT 1, hostname, port, max_connections, comment
-        FROM mysql_servers WHERE hostgroup_id = ${READER_HG};
-    INSERT OR IGNORE INTO mysql_replication_hostgroups (writer_hostgroup, reader_hostgroup, comment)
-        VALUES (0, 1, 'basictests alias');
-"
-
-# Remap users, query rules, and replication hostgroups to 0/1
+# Replace replication hostgroup mapping
+${MYSQL_CMD} -e "DELETE FROM mysql_replication_hostgroups WHERE writer_hostgroup = ${WRITER_HG};"
+${MYSQL_CMD} -e "INSERT OR REPLACE INTO mysql_replication_hostgroups (writer_hostgroup, reader_hostgroup, comment) VALUES (0, 1, 'basictests');"
+
+# Update users
 ${MYSQL_CMD} -e "UPDATE mysql_users SET default_hostgroup = 0 WHERE default_hostgroup = ${WRITER_HG};"
+
+# Update query rules
 ${MYSQL_CMD} -e "UPDATE mysql_query_rules SET destination_hostgroup = 0 WHERE destination_hostgroup = ${WRITER_HG};"
 ${MYSQL_CMD} -e "UPDATE mysql_query_rules SET destination_hostgroup = 1 WHERE destination_hostgroup = ${READER_HG};"
 
-# Load all changes to runtime
+# Load all to runtime
 ${MYSQL_CMD} -e "LOAD MYSQL SERVERS TO RUNTIME;"
 ${MYSQL_CMD} -e "LOAD MYSQL USERS TO RUNTIME;"
 ${MYSQL_CMD} -e "LOAD MYSQL QUERY RULES TO RUNTIME;"
 
-echo ">>> Hostgroup aliasing done."
+echo ">>> Hostgroup remapping done."