resource_control: add repeats to tidb_runaway_queries (pingcap#18909)

Author: lilin90

tidb-resource-control.md

@@ -399,19 +399,23 @@ You can get more information about runaway queries from the following system tab
     MySQL [(none)]> SELECT * FROM mysql.tidb_runaway_queries LIMIT 1\G
     *************************** 1. row ***************************
     resource_group_name: default
-                   time: 2024-09-06 17:43:09
-             match_type: identify
-                 action: kill
-           original_sql: select * from sbtest.sbtest1
-            plan_digest: cef718bcf4137307a8167e595941a92a260deb7dd9e1c9735bfba3ce3542de0f
-            tidb_server: 127.0.0.1:4000
-                   rule: RequestUnit = RRU:10.838106, WRU:0.000000, WaitDuration:0s(10)
+         start_time: 2024-09-09 17:43:42
+            repeats: 2
+         match_type: watch
+             action: kill
+         sample_sql: select sleep(2) from t
+         sql_digest: 4adbc838b86c573265d4b39a3979d0a362b5f0336c91c26930c83ab187701a55
+        plan_digest: 5d094f78efbce44b2923733b74e1d09233cb446318293492901c5e5d92e27dbc
+        tidb_server: 127.0.0.1:4000
     ```
 
-    In the preceding output,`match_type` indicates how the runaway query is identified. The value can be one of the following:
+    Field description:
 
-    - `identify` means that it matches the condition of the runaway query.
-    - `watch` means that it matches the quick identification rule in the watch list.
+    - `start_time` indicates the time when the runaway query is identified.
+    - `repeats` indicates the number of times the runaway query has been identified since `start_time`.
+    - `match_type` indicates how the runaway query is identified. The value can be one of the following:
+        - `identify` means that it matches the condition of the runaway query.
+        - `watch` means that it matches the quick identification rule in the watch list.
 
 + The `information_schema.runaway_watches` table contains records of quick identification rules for runaway queries. For more information, see [`RUNAWAY_WATCHES`](/information-schema/information-schema-runaway-watches.md).