[BugFix] Do not cache metadata json files in IcebergCachingFileIO

[Youngwb]

Why I'm doing:

Fixes #54786

What I'm doing:

Do not cache metadata json files because the name could be same, like "v1.metadata.json" when re-create table with same name.

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 3.4
  • 3.3
  • 3.2
  • 3.1
  • 3.0

[DorianZheng]

I'm afraid about the cold query performance if we don't cache it. What do you think?

[zombee0]

I'm afraid about the cold query performance if we don't cache it. What do you think?

+1

[jason-heo]

Hello.

I'm the author of #54786

I’m new to StarRocks and have a quick question.

Does REFRESH EXTERNAL TABLE invalidate the metadata cache?

If not, could you please let me know which caches are flushed after running REFRESH EXTERNAL TABLE?

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Youngwb]

@DorianZheng @zombee0 This PR do not cache the metadata json file for iceberg hadoop catalog, It does not affect the performance of hive/glue catalog

[Youngwb]

Hello.

I'm the author of #54786

I’m new to StarRocks and have a quick question.

Does REFRESH EXTERNAL TABLE invalidate the metadata cache?

If not, could you please let me know which caches are flushed after running REFRESH EXTERNAL TABLE?

REFRESH EXTERNAL TABLE do not invalidate the metadata file cache, It only invalidate iceberg table snapshot cache, and reload the latest snapshot from metadata file, but metadata file is cached in icebergCachingFileIO(It should not be cached), so the REFRESH EXTERNAL TABLE does not work here

[jason-heo]

@Youngwb

Thank you for your detailed answer :)

It would be nice if your explanation is described on the documentation

[github-actions]

[Java-Extensions Incremental Coverage Report]

✅ pass : 0 / 0 (0%)

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 5 / 5 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	com/starrocks/connector/iceberg/io/IcebergCachingFileIO.java	5	5	100.00%	[]

[github-actions]

[BE Incremental Coverage Report]

✅ pass : 0 / 0 (0%)