The timeout is too short for fetching data of INFORMATION_SCHEMA.TIFLASH_TABLES #57816
Description
Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
An issue reported in the asktug (https://asktug.com/t/topic/1036157/1)
mysql> select * from INFORMATION_SCHEMA.TIFLASH_TABLES limit 1\G
ERROR 1105 (HY000): rpc error: code = DeadlineExceeded desc = context deadline exceeded
2. What did you expect to see? (Required)
3. What did you see instead (Required)
The timeout is only 1 second for fetching the system table from tiflash instance. When there are thousand of table with tiflash replica, the query easily run into timeout.
https://github.com/pingcap/tidb/blob/v7.5.4/pkg/executor/infoschema_reader.go#L3081-L3083
Timeout is 1 second since #42720
There are about 5000 tables/partition in the cluster.
mysql> select count(*) from INFORMATION_SCHEMA.TIFLASH_REPLICA;
+----------+
| count(*) |
+----------+
| 3090 |
+----------+
1 row in set (0.04 sec)
mysql> select count(*) from INFORMATION_SCHEMA.TIFLASH_REPLICA t join INFORMATION_SCHEMA.partitions p on t.table_schema = p.table_schema and t.table_name= p.table_name;
+----------+
| count(*) |
+----------+
| 4892 |
+----------+
1 row in set (0.30 sec)
4. What is your TiDB version? (Required)
v7.5.4