The query may be blocking after identifying a runaway query with a cooldown action.

[nolouch]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

prepare data

use test;
create table t (id int auto_increment, k int,c varchar(255),  unique index(id));
insert into t (k,c) values (1,'abcqwer');
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
insert into t (k,c) select k,c from t;
split table t between (0) and (135536) regions 100;

create table t2 (id int auto_increment, k int,c varchar(255),  unique index(id));
insert into t2 (k,c) values (1,'abcqwer');
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
insert into t2 (k,c) select k,c from t2;
split table t2 between (0) and (135536) regions 100;

add resource group

create user IF NOT EXISTS rg1;
GRANT ALL PRIVILEGES ON *.* TO rg1;
CREATE RESOURCE GROUP IF NOT EXISTS rg1 RU_PER_SEC = 1000 QUERY_LIMIT=(EXEC_ELAPSED '1ms' ACTION  COOLDOWN WATCH = PLAN);
ALTER USER rg1 RESOURCE GROUP rg1;

run twice SQL with user rg1:

SELECT * FROM t use index(id),t2  use index(id) WHERE t.id IN (2341, 4165, 9296, 11817, 12777, 16624, 17053, 17774, 18116, 18676, 19961, 21765, 21802, 23445, 23505, 24263, 24390, 24875, 25957, 27511, 29661, 29857, 30594, 35296, 37182, 38732, 41018, 43542, 44735, 49167, 50970, 51187, 52959, 54317, 54875, 58803, 58826, 62412, 62533, 63510, 64303, 65832, 66437, 66454, 66855, 68154, 68672, 69308, 70891, 76299, 77548, 79204, 80046, 84291, 84348, 84547, 86196, 86812, 89537, 89570, 91826, 94030, 94906, 96240, 96642, 97319, 98775, 99893, 100022, 101823, 101931, 103945, 104560, 104954, 107281, 109624, 110020, 111812, 112112, 113417, 113485, 113711, 113931, 114348, 114885, 116465, 117571, 118674, 121347, 122221, 122716, 122965, 126227, 127175, 127815, 128580, 129646, 130410, 132717, 133089) or  t2.id between 1 and  10 or t2.id between 124660 and 132790;

2. What did you expect to see? (Required)

SQL can run

3. What did you see instead (Required)

SQL blocking forever

4. What is your TiDB version? (Required)

8.4