YQ-4779 fixed ACK sending for sys view scan

[GrigoriyPA]

Changelog entry

Fixed ACK sending for sys view scan

Changelog category

• Bugfix

Description for reviewers

Bugfix ticket: YQ-4779

[Copilot]

Pull Request Overview

This PR fixes ACK sending for system view scan operations by introducing a new TScanActorWithoutBackPressure base class and preventing duplicate scan initialization across multiple system view scan actors.

• Introduced TScanActorWithoutBackPressure template class to handle ACK processing without backpressure
• Added guards to prevent duplicate scan requests in tablet and query stats scan actors
• Refactored multiple system view scan classes to use the new base class and simplified ACK handling

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
ydb/core/sys_view/common/scan_actor_base_impl.h	Added new TScanActorWithoutBackPressure template class
ydb/core/sys_view/tablets/tablets.cpp	Added guard to prevent duplicate tablet ID requests
ydb/core/sys_view/query_stats/query_stats.cpp	Added guard to prevent duplicate old scan initialization
ydb/core/sys_view/storage/base.h	Migrated to use TScanActorWithoutBackPressure base class
ydb/core/sys_view/show_create/show_create.cpp	Migrated to use TScanActorWithoutBackPressure base class
ydb/core/sys_view/resource_pools/resource_pools.cpp	Migrated to use TScanActorWithoutBackPressure base class
ydb/core/sys_view/resource_pool_classifiers/resource_pool_classifiers.cpp	Migrated to use TScanActorWithoutBackPressure base class
ydb/core/sys_view/nodes/nodes.cpp	Migrated to use TScanActorWithoutBackPressure base class
ydb/core/sys_view/compile_cache/compile_cache.cpp	Added guard for pending proxy node requests and improved initialization
ydb/core/sys_view/auth/users.cpp	Migrated to use TScanActorWithoutBackPressure base class
ydb/core/sys_view/auth/auth_scan_base.h	Added guard to prevent duplicate navigation path requests
ydb/core/kqp/compute_actor/kqp_pure_compute_actor.h	Added new methods for source polling and free space calculation
ydb/core/kqp/compute_actor/kqp_pure_compute_actor.cpp	Implemented source polling logic and refactored free space calculation

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[github-actions]

🟢 2025-10-08 11:01:24 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-10-08 11:03:05 UTC Pre-commit check linux-x86_64-relwithdebinfo for 9c96d7e has started.
⚪ 2025-10-08 11:03:35 UTC Artifacts will be uploaded here
⚫ 2025-10-08 11:06:32 UTC Check cancelled

[github-actions]

⚪ 2025-10-08 11:04:36 UTC Pre-commit check linux-x86_64-release-asan for 9c96d7e has started.
⚪ 2025-10-08 11:04:53 UTC Artifacts will be uploaded here
⚫ 2025-10-08 11:06:32 UTC Check cancelled

[github-actions]

⚪ 2025-10-08 11:09:49 UTC Pre-commit check linux-x86_64-release-asan for a86c33c has started.
⚪ 2025-10-08 11:10:03 UTC Artifacts will be uploaded here
⚪ 2025-10-08 11:13:44 UTC ya make is running...
🟡 2025-10-08 13:45:30 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15722	15247	0	179	273	23

🟢 2025-10-08 13:45:37 UTC Build successful.
🟡 2025-10-08 13:46:04 UTC ydbd size 3.7 GiB changed* by +311.1 KiB, which is >= 100.0 KiB vs main: Warning

ydbd size dash	main: c38c114	merge: a86c33c	diff	diff %
ydbd size	4 021 180 208 Bytes	4 021 498 728 Bytes	+311.1 KiB	+0.008%
ydbd stripped size	1 494 048 320 Bytes	1 494 062 784 Bytes	+14.1 KiB	+0.001%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2025-10-08 11:12:48 UTC Pre-commit check linux-x86_64-relwithdebinfo for a86c33c has started.
⚪ 2025-10-08 11:12:52 UTC Artifacts will be uploaded here
⚪ 2025-10-08 11:16:22 UTC ya make is running...
🟡 2025-10-08 12:57:08 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
38673	35909	0	3	2739	22

⚪ 2025-10-08 12:57:20 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-10-08 13:14:29 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
263 (only retried tests)	245	0	1	0	17

⚪ 2025-10-08 13:14:32 UTC ya make is running... (failed tests rerun, try 3)
🟢 2025-10-08 13:23:49 UTC Tests successful.

Ya make output | Test bloat | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
188 (only retried tests)	173	0	0	0	15

🟢 2025-10-08 13:23:52 UTC Build successful.
🟢 2025-10-08 13:24:10 UTC ydbd size 2.3 GiB changed* by +12.5 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: c38c114	merge: a86c33c	diff	diff %
ydbd size	2 418 004 960 Bytes	2 418 017 768 Bytes	+12.5 KiB	+0.001%
ydbd stripped size	515 030 344 Bytes	515 032 968 Bytes	+2.6 KiB	+0.001%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}