variable: set max duration of gc interval/lifetime to 365 days

[morgo]

What problem does this PR solve?

Problem Summary:

In pingcap/docs#5752 I am working through a PR to document min/max, scope etc of system variables by generating it from the TiDB server source. This has revealed that the max values for gc interval/lifetime are quite large (292 years).

It is a very minor issue, but in this PR I propose we change it to 365 days. It is inspired by similar "time based" values in MySQL such as https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_lock_wait_timeout (1 year). The rationale for the change is that Golang doesn't print 292 years in a user-friendly way.

What is changed and how it works?

What's Changed:

The maximum duration for gc interval/lifetime changes from 292 years to 365 days. This is not expected to cause issues for users, since the typical range is specified in minutes to hours.

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch

Check List

Tests

• Unit test (covered by existing tests)

Side effects

• None

Release note

• The maximum duration for gc interval/lifetime changes from 292 years to 365 days. This is not expected to cause issues for users, since the typical range is specified in minutes to hours.

[dveeden]

5.7.25-TiDB-v5.2.0-alpha-14-g75388187f 127.0.0.1:4000  SQL  set global tidb_gc_life_time='9m';
ERROR: 1232 (42000): Incorrect argument type to variable 'tidb_gc_life_time'

Not that this should be part of this PR, but this error is both unhelpful and wrong.

• The type is not wrong, the value is.
• Would be nice to have it report the range.

Just and idea:

5.7.25-TiDB-v5.2.0-alpha-14-g75388187f 127.0.0.1:4000  SQL  set global tidb_gc_life_time='9m';
ERROR: 1232 (42000): Out of range value for variable 'tidb_gc_life_time'. Allowed range: 10m0s - 1y

[morgo]

5.7.25-TiDB-v5.2.0-alpha-14-g75388187f 127.0.0.1:4000  SQL  set global tidb_gc_life_time='9m';
ERROR: 1232 (42000): Incorrect argument type to variable 'tidb_gc_life_time'

Not that this should be part of this PR, but this error is both unhelpful and wrong.

• The type is not wrong, the value is.
• Would be nice to have it report the range.

Just and idea:

5.7.25-TiDB-v5.2.0-alpha-14-g75388187f 127.0.0.1:4000  SQL  set global tidb_gc_life_time='9m';
ERROR: 1232 (42000): Out of range value for variable 'tidb_gc_life_time'. Allowed range: 10m0s - 1y

This is easy to fix:

tidb/sessionctx/variable/sysvar.go

Lines 344 to 349 in a45b3aa

	if int64(d) < sv.MinValue {
	return value, ErrWrongTypeForVar.GenWithStackByArgs(sv.Name)
	}
	if uint64(d) > sv.MaxValue {
	return value, ErrWrongTypeForVar.GenWithStackByArgs(sv.Name)
	}

I don't think it will break many tests to fix this case, but the functions that validate integer values also return 'wrong type'. Fixing these might break a fair amount of tests.

[ti-chi-bot]

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• dveeden
• xhebox

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[xhebox]

/merge

[ti-chi-bot]

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

Commit hash: f1fd49d

[ti-chi-bot]

@morgo: Your PR was out of date, I have automatically updated it for you.

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/run-all-tests

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