ddl: make concurrent ingest job queue instead of fallback

[tangenta]

What problem does this PR solve?

Issue Number: close #47758

Problem Summary:

1. only 1 ddl job can use ingest model and global sort.
2. another add index job using txn merge.

What is changed and how it works?

• This PR fixes problem 2 by making the concurrent adding index job queue.
• Remove useless code.
• Refactor improper usage of system variable.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
  Add time.Sleep(20*time.Second) to the first phase of onCreateIndex().
  Session 1:

  mysql> alter table t add index i1 (a);
  Query OK, 0 rows affected (27.02 sec)
  

  Session 2:

  mysql> alter table t add index i2 (b);
  Query OK, 0 rows affected (46.31 sec)
  mysql> admin show ddl jobs 2;
  +--------+---------+------------+------------------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
  | JOB_ID | DB_NAME | TABLE_NAME | JOB_TYPE               | SCHEMA_STATE | SCHEMA_ID | TABLE_ID | ROW_COUNT | CREATE_TIME         | START_TIME          | END_TIME            | STATE  |
  +--------+---------+------------+------------------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
  |    110 | test    | t          | add index /* ingest */ | public       |         2 |      104 |         3 | 2023-11-16 16:47:15 | 2023-11-16 16:47:38 | 2023-11-16 16:48:01 | synced |
  |    109 | test    | t          | add index /* ingest */ | public       |         2 |      104 |         3 | 2023-11-16 16:47:14 | 2023-11-16 16:47:14 | 2023-11-16 16:47:38 | synced |
  +--------+---------+------------+------------------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
  2 rows in set (0.00 sec)
  

  Both jobs can use ingest now. You can also check the log:

  [2023/11/16 16:47:15.427 +08:00] [INFO] [backend_mgr.go:79] ["ingest backfill worker is already in used by another DDL job"] [category=ddl-ingest] ["processing job ID"=109]
  

• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[tiprow]

Hi @tangenta. Thanks for your PR.

PRs from untrusted users cannot be marked as trusted with /ok-to-test in this repo meaning untrusted PR authors can never trigger tests themselves. Collaborators can still trigger tests on the PR using /test all.

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[ywqzzy]

If enbaleDistTask == true and enableFastReorg == false, what will happen?

[tangenta]

mysql> set global tidb_enable_dist_task = 1;
Query OK, 0 rows affected (0.02 sec)

mysql> set global tidb_ddl_enable_fast_reorg = 0;
Query OK, 0 rows affected (0.03 sec)

mysql> alter table t add index i3(c);
Query OK, 0 rows affected (0.43 sec)

mysql> admin show ddl jobs 1;
+--------+---------+------------+---------------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
| JOB_ID | DB_NAME | TABLE_NAME | JOB_TYPE            | SCHEMA_STATE | SCHEMA_ID | TABLE_ID | ROW_COUNT | CREATE_TIME         | START_TIME          | END_TIME            | STATE  |
+--------+---------+------------+---------------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
|    111 | test    | t          | add index /* txn */ | public       |         2 |      104 |         3 | 2023-11-16 17:16:52 | 2023-11-16 17:16:52 | 2023-11-16 17:16:53 | synced |
+--------+---------+------------+---------------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
1 row in set (0.01 sec)

[codecov]

Codecov Report

Merging #48645 (b949d74) into master (3d176fc) will increase coverage by 1.5827%.
Report is 1 commits behind head on master.
The diff coverage is 53.8461%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #48645        +/-   ##
================================================
+ Coverage   71.1018%   72.6846%   +1.5827%     
================================================
  Files          1365       1389        +24     
  Lines        404348     411021      +6673     
================================================
+ Hits         287499     298749     +11250     
+ Misses        96883      93375      -3508     
+ Partials      19966      18897      -1069     

Flag	Coverage Δ
integration	43.5754% <41.7582%> (?)
unit	71.1102% <53.8461%> (+0.0083%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	53.9874% <ø> (ø)
parser	∅ <ø> (∅)
br	48.7687% <ø> (-4.3201%)	⬇️

[ywqzzy]

/hold

[ywqzzy]

/unhold

[Benjamin2037]

Why here use

Suggested change

	Unsupported tidb_enable_dist_task setting. Please enable tidb_ddl_enable_fast_reorg to use distributed task execution.
	Unsupported tidb_enable_dist_task setting. To utilize distributed task execution, please enable tidb_ddl_enable_fast_reorg first.

[GMHDBJD]

LGTM

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: GMHDBJD, ywqzzy

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Needs approval from an approver in each of these files:

• OWNERS [GMHDBJD]
• pkg/ddl/OWNERS [ywqzzy]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-11-16 09:44:34.770032581 +0000 UTC m=+4328672.357142726: ☑️ agreed by ywqzzy.
• 2023-11-17 09:18:01.68907343 +0000 UTC m=+4413479.276183559: ☑️ agreed by GMHDBJD.

[tangenta]

/retest

[tiprow]

@tangenta: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

In response to this:

/retest

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[tangenta]

/retest

[tiprow]

@tangenta: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

In response to this:

/retest

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[hawkingrei]

/ok-to-test

[tangenta]

/retest

[hawkingrei]

/test all

[hawkingrei]

/retest

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #48739.