ddl: roll back txn before handling ErrEntryTooLarge

[tangenta]

What problem does this PR solve?

Issue Number: close #43725

Problem Summary:

DDL will use the same transaction to complete the update of the schema (onCreateTables) and the update of the job status (updateDDLJob). When the latter reports ErrEntryTooLarge error, it does not roll back the schema update, but sets the job to canceled and commits, resulting in the illusion that the DDL failed but the schema was actually updated.

err = w.updateDDLJob(t, job, runJobErr != nil)
if err = w.handleUpdateJobError(t, job, err); err != nil { // ---------------- ErrEntryTooLarge is ignored
    w.sess.rollback()
    d.unlockSchemaVersion(job.ID)
    return 0, err
}
writeBinlog(d.binlogCli, txn, job)
w.sess.GetSessionVars().StmtCtx.ResetSQLDigest(job.Query)
err = w.sess.commit()                                      // ---------------- the schema is updated here

What is changed and how it works?

• Roll back the transaction before handling ErrEntryTooLarge.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

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]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• wjhuang2016
• zimulala

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[tangenta]

/retest

[zimulala]

LGTM

[tangenta]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 3c91d0c

[hawkingrei]

/retest

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #43878.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #43879.