jiaqizho opened a new pull request, #1304:
URL: https://github.com/apache/cloudberry/pull/1304
The autovacuum launcher process periodically launches workers to vacuum the
table. During this process, the UDF `pg_catalog.gp_acquire_sample_rows` will be
called. Also the vacuum task always be canceled by launcher.
The plan of `pg_catalog.gp_acquire_sample_rows` is:
```
QUERY PLAN
---------------------------------------------------------------------------------
Gather Motion 3:1 (slice1; segments: 3) (cost=0.00..45.02 rows=3000
width=32)
Output: (gp_acquire_sample_rows('17018'::oid, 1250, false))
-> ProjectSet (cost=0.00..5.02 rows=1000 width=32)
Output: gp_acquire_sample_rows('17018'::oid, 1250, false)
-> Result (cost=0.00..0.01 rows=1 width=0)
Optimizer: Postgres query optimizer
(6 rows)
```
In actual examples, we often encounter relcache leaks caused by
`pg_catalog.gp_acquire_sample_rows`. In fact, this warning is not caused by the
UDF itself.
The following are the complete steps to reproduce(not stable reproduce)
1. User use the insert/update/delete SQL. Auto-vacuum is enabled.
2. The auto-vacuum worker process call the
`pg_catalog.gp_acquire_sample_rows` 2.1 The vacuum launches in master cancel
the vacuum query. 2.2 The vacuum worker in master process the interrupt in the
intercontect. So the gather motion will be aborted. 2.3 The segment do the
tuple sender in the motion(`doSendTuple`).But it found the connection is NOT
alive. Also it have not recv the SIGN INT in this time. So segment mark the
`StopRequested` to true, and finish the current motion, and the function
`pg_catalog.gp_acquire_sample_rows` in project set can't call the `table_close`
in this time. 2.4 The segment call the `PortalDrop` to destory the resowner
which inside the current portal, and current portal status won't be FAIL,
because current segment still have not recv the SIGN INT. The resowner found
the leaked relcache, log the WARNING.
3. After step2, segments recv the SIGN INT, But nothing to do.
<!-- Thank you for your contribution to Apache Cloudberry (Incubating)! -->
Fixes #ISSUE_Number
### What does this PR do?
<!-- Brief overview of the changes, including any major features or fixes -->
### Type of Change
- [ ] Bug fix (non-breaking change)
- [ ] New feature (non-breaking change)
- [ ] Breaking change (fix or feature with breaking changes)
- [ ] Documentation update
### Breaking Changes
<!-- Remove if not applicable. If yes, explain impact and migration path -->
### Test Plan
<!-- How did you test these changes? -->
- [ ] Unit tests added/updated
- [ ] Integration tests added/updated
- [ ] Passed `make installcheck`
- [ ] Passed `make -C src/test installcheck-cbdb-parallel`
### Impact
<!-- Remove sections that don't apply -->
**Performance:**
<!-- Any performance implications? -->
**User-facing changes:**
<!-- Any changes visible to users? -->
**Dependencies:**
<!-- New dependencies or version changes? -->
### Checklist
- [ ] Followed [contribution
guide](https://cloudberry.apache.org/contribute/code)
- [ ] Added/updated documentation
- [ ] Reviewed code for security implications
- [ ] Requested review from [cloudberry
committers](https://github.com/orgs/apache/teams/cloudberry-committers)
### Additional Context
<!-- Any other information that would help reviewers? Remove if none -->
### CI Skip Instructions
<!--
To skip CI builds, add the appropriate CI skip identifier to your PR title.
The identifier must:
- Be in square brackets []
- Include the word "ci" and either "skip" or "no"
- Only use for documentation-only changes or when absolutely necessary
-->
---
<!-- Join our community:
- Mailing list:
[[email protected]](https://lists.apache.org/[email protected])
(subscribe: [email protected])
- Discussions: https://github.com/apache/cloudberry/discussions -->
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
