deprioritise system tablets in balancer

[vporyadke]

Changelog entry

make less coordinator&mediator moves

Changelog category

• Performance improvement

Additional information

...

[github-actions]

⚪ 2024-07-18 16:30:54 UTC Pre-commit check for 065e373 has started.
⚪ 2024-07-18 16:33:51 UTC Build+Tests linux-x86_64-release-clang14 is running...
🟢 2024-07-18 17:07:24 UTC Build successful.

[github-actions]

⚪ 2024-07-18 16:30:54 UTC Pre-commit check for 065e373 has started.
⚪ 2024-07-18 16:33:49 UTC Build+Tests linux-x86_64-release-asan is running...
🟢 2024-07-18 19:01:32 UTC Build successful.
🔴 2024-07-18 19:03:30 UTC Some tests failed, follow the links below.

Test history | Ya make output

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
11029	10438	0	96	323	172

🟢 2024-07-18 19:04:15 UTC ydbd size 5.2 GiB changed* by +16.0 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: d1fc6c4	merge: 065e373	diff	diff %
ydbd size	5 546 630 944 Bytes	5 546 647 296 Bytes	+16.0 KiB	+0.000%
ydbd stripped size	1 195 268 144 Bytes	1 195 271 088 Bytes	+2.9 KiB	+0.000%

^{*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]

⚪ 2024-07-18 16:31:20 UTC Pre-commit check for 065e373 has started.
⚪ 2024-07-18 16:34:22 UTC Build+Tests linux-x86_64-relwithdebinfo is running...
🟢 2024-07-18 18:51:48 UTC Build successful.
🔴 2024-07-18 18:56:09 UTC Some tests failed, follow the links below.

Test history | Ya make output

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
39559	34314	0	7	5222	16

🟢 2024-07-18 18:56:54 UTC ydbd size 8.0 GiB changed* by +19.6 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: d1fc6c4	merge: 065e373	diff	diff %
ydbd size	8 642 072 136 Bytes	8 642 092 200 Bytes	+19.6 KiB	+0.000%
ydbd stripped size	470 505 760 Bytes	470 506 848 Bytes	+1.1 KiB	+0.000%

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

[adameat]

I would advise of not using first-last semantics, where it's clear that it's a begin-end semantics.
the key difference is that "last" usually points to existing element, while "end" points to the position, after the last element