Improve CHECK TABLE system query

[vdimir]

Changelog category (leave one):

• Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

• QueryCHECK TABLE has better performance and usability (sends progress updates, cancellable)

TODO

• Document this query
• Add test for progress and cancellation

[robot-clickhouse-ci-2]

This is an automated comment for commit 1183dac with description of existing statuses. It's updated for the latest CI running
The full report is available here
The overall status of the commit is 🔴 failure

Check name	Description	Status
AST fuzzer	Runs randomly generated queries to catch program errors. The build type is optionally given in parenthesis. If it fails, ask a maintainer for help	🟢 success
CI running	A meta-check that indicates the running CI. Normally, it's in success or pending state. The failed status indicates some problems with the PR	🟢 success
ClickHouse build check	Builds ClickHouse in various configurations for use in further steps. You have to fix the builds that fail. Build logs often has enough information to fix the error, but you might have to reproduce the failure locally. The cmake options can be found in the build log, grepping for cmake. Use these options and follow the general build process	🟢 success
Compatibility check	Checks that clickhouse binary runs on distributions with old libc versions. If it fails, ask a maintainer for help	🟢 success
Docker image for servers	The check to build and optionally push the mentioned image to docker hub	🟢 success
Docs Check	Builds and tests the documentation	🟢 success
Fast test	Normally this is the first check that is ran for a PR. It builds ClickHouse and runs most of stateless functional tests, omitting some. If it fails, further checks are not started until it is fixed. Look at the report to see which tests fail, then reproduce the failure locally as described here	🟢 success
Flaky tests	Checks if new added or modified tests are flaky by running them repeatedly, in parallel, with more randomization. Functional tests are run 100 times with address sanitizer, and additional randomization of thread scheduling. Integrational tests are run up to 10 times. If at least once a new test has failed, or was too long, this check will be red. We don't allow flaky tests, read the doc	🟢 success
Install packages	Checks that the built packages are installable in a clear environment	🟢 success
Integration tests	The integration tests report. In parenthesis the package type is given, and in square brackets are the optional part/total tests	🟢 success
Mergeable Check	Checks if all other necessary checks are successful	🟢 success
Performance Comparison	Measure changes in query performance. The performance test report is described in detail here. In square brackets are the optional part/total tests	🔴 failure
Push to Dockerhub	The check for building and pushing the CI related docker images to docker hub	🟢 success
SQLancer	Fuzzing tests that detect logical bugs with SQLancer tool	🟢 success
Sqllogic	Run clickhouse on the sqllogic test set against sqlite and checks that all statements are passed	🟢 success
Stateful tests	Runs stateful functional tests for ClickHouse binaries built in various configurations -- release, debug, with sanitizers, etc	🟢 success
Stateless tests	Runs stateless functional tests for ClickHouse binaries built in various configurations -- release, debug, with sanitizers, etc	🟢 success
Stress test	Runs stateless functional tests concurrently from several clients to detect concurrency-related errors	🟢 success
Style Check	Runs a set of checks to keep the code style clean. If some of tests failed, see the related log from the report	🟢 success
Unit tests	Runs the unit tests for different release types	🟢 success
Upgrade check	Runs stress tests on server version from last release and then tries to upgrade it to the version from the PR. It checks if the new server can successfully startup without any errors, crashes or sanitizer asserts	🟢 success

[nikitamikhaylov]

I'm not sure, but I thought this query is single-threaded.. Is it true? Can we make it parallelized?

[alesapin]

I think we have tests for progress, maybe it make sense to add it here.

[alesapin]

Isn't it a semantic change? I think we should process all data parts regardless of check_query_single_value_result.

[vdimir]

I assumed it was good to have a mode with early exit and thought we could do it since the user couldn't know how many errors there were with single-value result. However, it's doubtful, so I returned it to the original behavior.

[vdimir]

@alesapin

I updated the implementation to build a more sophisticated pipeline and use its features properly.

It allowed to eliminate std::async and sleep entirely and execute everything in the pipeline executor pool. And also query is naturally parallelized like any other query.

I split checkData into two methods:
The first method obtains some container with a list of work to check table (parts or files depending on an engine). And the second executes one entry from this list.
We retrieve all sets of parts to check and then simultaneously execute entries from it by several processors.

I also added a doc (we have this query documented, so I added more information and examples) and added a test for progress.

[alesapin]

we return chunk only once, right?

[vdimir]

Yes, only one block with single row is expected in the result

[vdimir]

Docs Check — Found errors in docs Details

[ERROR] Error: Docusaurus found broken links!

Please check the pages of your site in the list below, and make sure you don't reference any path that does not exist.
Note: it's possible to ignore broken links with the 'onBrokenLinks' Docusaurus configuration, and let the build pass.

Exhaustive list of all broken links found:

- On source page path = /docs/en/sql-reference/statements/check-table:
   -> linking to ../../operations/settings/settings.md#settings-max_threads (resolved as: /docs/en/operations/settings/settings.md)

- On source page path = /docs/zh/sql-reference/statements/check-table:
   -> linking to ../../operations/settings/settings.md#settings-max_threads (resolved as: /docs/zh/operations/settings/settings.md)

The path ../../operations/settings/settings.md#settings-max_threads should be ok

$ cd docs/en/sql-reference/statements
$ cat ../../operations/settings/settings.md | grep -F settings-max_threads
## max_threads {#settings-max_threads}
Parallel `INSERT SELECT` has effect only if the `SELECT` part is executed in parallel, see [max_threads](#settings-max_threads) setting.
$ 

[tavplubix]

Looks like it makes 01710_projection_part_check flaky:
https://s3.amazonaws.com/clickhouse-test-reports/0/57025eed65ab0962464c23254c3394ecbfd98aef/stateless_tests__asan__[4_4].html
https://s3.amazonaws.com/clickhouse-test-reports/0/57025eed65ab0962464c23254c3394ecbfd98aef/stateless_tests__msan__[2_6].html

[tavplubix]

And the CI caught it, it failed on commit dc98d33:
https://s3.amazonaws.com/clickhouse-test-reports/52745/dc98d3393804590b3c6aab6a1c049e14d345b41b/fast_test.html