diff --git a/plugins/shard/shard-plugin.c b/plugins/shard/shard-plugin.c
index 1ffec69..8cf893b 100644
--- a/plugins/shard/shard-plugin.c
+++ b/plugins/shard/shard-plugin.c
@@ -1294,6 +1294,11 @@ proxy_get_pooled_connection(network_mysqld_con *con,
     if (type == BACKEND_TYPE_RW) {
         backend = backend_group->master;    /* may be NULL if master down */
         if (!backend || (backend->state != BACKEND_STATE_UP && backend->state != BACKEND_STATE_UNKNOWN)) {
+            if (backend) {
+                g_message("%s: backend->state:%d", G_STRLOC, backend->state);
+            } else {
+                g_message("%s: backend is nil", G_STRLOC);
+            }
             *server_unavailable = 1;
             return FALSE;
         }
@@ -1313,6 +1318,7 @@ proxy_get_pooled_connection(network_mysqld_con *con,
             con->slave_conn_shortaged = 1;
         }
 
+        g_message("%s: conn shortaged, type:%d", G_STRLOC, type);
         return FALSE;
     }
 
diff --git a/src/network-mysqld.c b/src/network-mysqld.c
index 075107b..7dd48b1 100644
--- a/src/network-mysqld.c
+++ b/src/network-mysqld.c
@@ -2327,7 +2327,6 @@ handle_query_wait_stats(network_mysqld_con *con)
 static void
 process_service_unavailable(network_mysqld_con *con)
 {
-
     con->state = ST_SEND_QUERY_RESULT;
     g_message("%s: service unavailable for con:%p", G_STRLOC, con);
 
@@ -2342,6 +2341,7 @@ process_service_unavailable(network_mysqld_con *con)
 
         con->server_to_be_closed = 1;
         con->dist_tran = 0;
+        con->is_in_transaction = 0;
     }
 #ifndef SIMPLE_PARSER
     if (con->servers != NULL) {