tidb_service_scope not works for Distributed eXecution Framework

[aytrack]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. deploy cluster with 3 tidb nodes
2. connect to tidb-0 and tidb-2 execute sql set global tidb_service_scope = "background";
3. check the mysql.dist_framework_meta
4. Import data

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

only background tidb nodes works for import data

3. What did you see instead (Required)

all the tidb nodes running for import data

[11:13:58]TiDB root:(none)> set global tidb_service_scope = "background";
Query OK, 0 rows affected
[11:14:00]TiDB root:(none)> select * from mysql.dist_framework_meta;
+---------------------------------------------------------------------------+------+-----------+-------------+
| host                                                                      | role | cpu_count | keyspace_id |
+---------------------------------------------------------------------------+------+-----------+-------------+
| tc-tidb-1.tc-tidb-peer.testbed-global-operator-tps-5550170-1-849.svc:4000 |      | 16        | -1          |
| tc-tidb-0.tc-tidb-peer.testbed-global-operator-tps-5550170-1-849.svc:4000 |      | 16        | -1          |
| tc-tidb-2.tc-tidb-peer.testbed-global-operator-tps-5550170-1-849.svc:4000 |      | 16        | -1          |
+---------------------------------------------------------------------------+------+-----------+-------------+

11:18:03]TiDB root:test> select id, task_key, type, state, step, exec_id, cast(error as char) from mysql.tidb_background_subtask where task_key = 1;
+----+----------+------+---------+------+---------------------------------------------------------------------------+---------------------+
| id | task_key | type | state   | step | exec_id                                                                   | cast(error as char) |
+----+----------+------+---------+------+---------------------------------------------------------------------------+---------------------+
| 1  | 1        | 2    | running | 3    | tc-tidb-0.tc-tidb-peer.testbed-global-operator-tps-5550170-1-849.svc:4000 | <null>              |
| 2  | 1        | 2    | running | 3    | tc-tidb-1.tc-tidb-peer.testbed-global-operator-tps-5550170-1-849.svc:4000 | <null>              |
| 3  | 1        | 2    | running | 3    | tc-tidb-2.tc-tidb-peer.testbed-global-operator-tps-5550170-1-849.svc:4000 | <null>              |
+----+----------+------+---------+------+---------------------------------------------------------------------------+---------------------+

4. What is your TiDB version? (Required)

[11:16:16]TiDB root:(none)> select tidb_version();
+-----------------------------------------------------------+
| tidb_version()                                            |
+-----------------------------------------------------------+
| Release Version: v7.6.0-alpha                             |
| Edition: Community                                        |
| Git Commit Hash: 62c83d40fe2ed742bfaf4b7c64eca0bb1853a94d |
| Git Branch: heads/refs/tags/v7.6.0-alpha                  |
| UTC Build Time: 2024-01-04 14:31:13                       |
| GoVersion: go1.21.5                                       |
| Race Enabled: false                                       |
| Check Table Before Drop: false                            |
| Store: tikv                                               |
+-----------------------------------------------------------+