add new system.zookeeper_watches table

[Diskein]

Implements #86736

Changelog category (leave one):

• New Feature

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

Users can now see zookeeper's watches issued by clickhouse-server using the new system.zookeeper_watches table.

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

[clickhouse-gh]

Workflow [PR], commit [2962b96]

Summary: ❌

job_name	test_name	status	info	comment
Integration tests (amd_asan, targeted)		failure
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[4-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[5-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[3-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[9-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[1-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[6-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[8-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[2-10]	FAIL	cidb
	test_move_ttl_broken_compatibility/test.py::test_bc_compatibility[7-10]	FAIL	cidb
	test_s3_aws_sdk_has_slightly_unreliable_behaviour/test.py::test_dataloss[7-10]	FAIL	cidb
	8 more test cases not shown

[Diskein]

create_time here is the time when we got response from our zookeeper and added callback on client for this watch

[clickhouse-gh]

LLVM Coverage Report

Metric	Baseline	Current	Δ
Lines	83.80%	83.80%	+0.00%
Functions	23.90%	23.90%	+0.00%
Branches	76.30%	76.30%	+0.00%

PR changed lines: PR changed-lines coverage: 92.82% (168/181, 0 noise lines excluded)
Diff coverage report
Uncovered code

[Diskein]

There is two unrelated failure which has been fixed already:

• Make test_s3_aws_sdk_has_slightly_unreliable_behaviour idempotent #100402
• fix targeted integration test test_move_ttl_broken_compatibility #100045

[Diskein]

@Michicosun could you take a look pls

[Michicosun]

First Review Notes

[Michicosun]

Basically, this structure duplicates the watches map, which doubles the byte size for watches. Why isn't this information stored not in watches map itself?

[Michicosun]

There is a bug in master; it should not remove all watches based on the triggered path; it should remove only the triggered watch.