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*: activate txn for query on infoschema tables (#57937) #57951

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This is an automated cherry-pick of #57937

What problem does this PR solve?

Issue Number: close #57874

Problem Summary:

The GC should be blocked by query.

What changed and how does it work?

There are two places that the transaction should blcok GC:

  • The query "SELECT COUNT(1) as c FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='SEQUENCE'" itself
  • The internal transaction meta.ListTables invoked by SchemaTableInfos() API

This commit just fix the first one. It should be enough to fix issue 57874.
The root cause is that whe we query on infoschema tables, the transaction is not activated.
So the session process info would not be collected to block GC.

The second issue is caused by the fact that the meta API call does not block GC.
I don't take investigation on it further more, meta API is limited used.

Check List

Tests

  • Unit test
  • Integration test
  • Manual test (add detailed scripts or steps below)

Modify the code and build tidb, check no more "GC life time is shorter than transaction duration" error.

diff --git a/pkg/planner/core/memtable_infoschema_extractor.go b/pkg/planner/core/memtable_infoschema_extractor.go
index c527dde968..34cabb3677 100644
--- a/pkg/planner/core/memtable_infoschema_extractor.go
+++ b/pkg/planner/core/memtable_infoschema_extractor.go
@@ -15,6 +15,7 @@
 package core
 
 import (
+       "time"
        "bytes"
        "context"
        "fmt"
@@ -184,6 +185,7 @@ func (e *InfoSchemaBaseExtractor) ListSchemasAndTables(
                return findTableAndSchemaByName(ctx, is, schemas, tableNames)
        }
        schemas := e.ListSchemas(is)
+       time.Sleep(12 * time.Minute)
        return listTablesForEachSchema(ctx, e, is, schemas)
 }
mysql> set @@tidb_mem_quota_query = 12*1024*1024*1024;
Query OK, 0 rows affected (0.00 sec)

mysql> select count(tidb_table_id) from information_schema.tables where table_name != 'test';
+----------------------+
| count(tidb_table_id) |
+----------------------+
|              1000818 |
+----------------------+
1 row in set (12 min 28.84 sec)
  • 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

@ti-chi-bot ti-chi-bot added release-note-none Denotes a PR that doesn't merit a release note. size/M Denotes a PR that changes 30-99 lines, ignoring generated files. type/cherry-pick-for-release-8.5 This PR is cherry-picked to release-8.5 from a source PR. labels Dec 3, 2024
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codecov bot commented Dec 3, 2024

Codecov Report

Attention: Patch coverage is 75.00000% with 8 lines in your changes missing coverage. Please review.

Please upload report for BASE (release-8.5@0eb3c0b). Learn more about missing BASE report.

Additional details and impacted files
@@               Coverage Diff                @@
##             release-8.5     #57951   +/-   ##
================================================
  Coverage               ?   56.9497%           
================================================
  Files                  ?       1772           
  Lines                  ?     627086           
  Branches               ?          0           
================================================
  Hits                   ?     357124           
  Misses                 ?     245878           
  Partials               ?      24084           
Flag Coverage Δ
integration 36.8292% <75.0000%> (?)
unit 72.6351% <75.0000%> (?)

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

Components Coverage Δ
dumpling 52.8711% <0.0000%> (?)
parser ∅ <0.0000%> (?)
br 52.2495% <0.0000%> (?)

@ti-chi-bot ti-chi-bot bot added approved needs-1-more-lgtm Indicates a PR needs 1 more LGTM. labels Dec 4, 2024
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ti-chi-bot bot commented Dec 4, 2024

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lance6716, wjhuang2016

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:
  • OWNERS [lance6716,wjhuang2016]

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@ti-chi-bot ti-chi-bot bot added lgtm and removed needs-1-more-lgtm Indicates a PR needs 1 more LGTM. labels Dec 4, 2024
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ti-chi-bot bot commented Dec 4, 2024

[LGTM Timeline notifier]

Timeline:

  • 2024-12-04 02:33:55.346469858 +0000 UTC m=+1208622.966124374: ☑️ agreed by lance6716.
  • 2024-12-04 03:02:58.975851031 +0000 UTC m=+1210366.595505541: ☑️ agreed by wjhuang2016.

@ti-chi-bot ti-chi-bot bot added cherry-pick-approved Cherry pick PR approved by release team. and removed do-not-merge/cherry-pick-not-approved labels Dec 4, 2024
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/test mysql-test

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tiprow bot commented Dec 4, 2024

@tiancaiamao: No presubmit jobs available for pingcap/[email protected]

In response to this:

/test mysql-test

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-sigs/prow repository.

@ti-chi-bot ti-chi-bot bot added cherry-pick-approved Cherry pick PR approved by release team. and removed cherry-pick-approved Cherry pick PR approved by release team. labels Dec 4, 2024
@ti-chi-bot ti-chi-bot bot merged commit 1df27e0 into pingcap:release-8.5 Dec 4, 2024
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4 participants