I created the Placement Rules but failed to create the table

TiDB Ops & Admin
1

Note that this question was originally posted on the Chinese TiDB Forum. We copied it here to help new users solve their problems quickly.

Application environment:

Test environment

TiDB version:

Cluster name: tidb_cluster_v6.0 Cluster version: TiDB v6.0.0

Reproduction method:

I deployed a TiDB cluster using TiUP Cluster

tiup cluster deploy tidb_cluster_v6.0 v6.0.0 /home/tidb/.tiup/storage/cluster/topology.yaml --ssh system

Then I created Placement Rules

CREATE PLACEMENT POLICY 'ke_policy' PRIMARY_REGION=“zeus” REGIONS=“zeus,mars,atlas” FOLLOWERS=4;

1519×318 23.6 KB

Problem:

I created the Placement Rules but failed to create the table. The log is as follows:

11:18 10.200.118.177:4000[Writable] (ke) > CREATE PLACEMENT POLICY 'ke_policy' PRIMARY_REGION=“zeus” REGIONS=“zeus,mars,atlas” FOLLOWERS=4;
Query OK, 0 rows affected (0.08 sec)
11:18 10.200.118.177:4000[Writable] (ke) > create table t1 (id int) PLACEMENT POLICY 'ke_policy' ;
ERROR 8243 (HY000): “[PD:placement:ErrRuleContent]invalid rule content, rule ‘table_rule_74_0’ from rule group ‘TiDB_DDL_74’ can not match any store”
11:19 10.200.118.177:4000[Writable] (ke) > create table t1 (id int);
Query OK, 0 rows affected (0.09 sec)
11:36 10.200.118.177:4000[Writable] (ke) > create table t2 (id int) PLACEMENT POLICY 'ke_policy' ;
ERROR 8243 (HY000): “[PD:placement:ErrRuleContent]invalid rule content, rule ‘table_rule_78_0’ from rule group ‘TiDB_DDL_78’ can not match any store”
11:40 10.200.118.177:4000[Writable] (ke) > show CREATE PLACEMENT POLICY 'ke_policy';
±----------±------------------------------------------------------------------------------------------------+
| Policy | Create Policy |
±----------±------------------------------------------------------------------------------------------------+
| ke_policy | CREATE PLACEMENT POLICY 'ke_policy' PRIMARY_REGION=“zeus” REGIONS=“zeus,mars,atlas” FOLLOWERS=4 |
±----------±------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
11:40 10.200.118.177:4000[Writable] (ke) > alter table t1 PLACEMENT POLICY 'ke_policy' ;
ERROR 8243 (HY000): “[PD:placement:ErrRuleContent]invalid rule content, rule ‘table_rule_76_0’ from rule group ‘TiDB_DDL_76’ can not match any store”
2 
policy ke_policy  LEADER_CONSTRAINTS="[+host=zeus]" FOLLOWER_CONSTRAINTS='{"+host=mars":1,"+host=atlas":1}';

The default PLACEMENT POLICY requires region as a distinguishing label. So when you create a TiKV, you need to explicitly specify the region label of the TiKV. Otherwise, you will not see the region label in the show placement labels.

3

Thanks, I got it! If you want fine-grained control, you need to label the region. But I don’t know how to label the region. Can you give an example?

4

You can refer to the parameter specification here: Tune TiKV Memory Parameter Performance | PingCAP Docs