Disagg: Fix the issue that lifetime of read-snapshots in WN may be longer than expected (#9297)

[ti-chi-bot]

This is an automated cherry-pick of #9297

What problem does this PR solve?

Issue Number: close #9298

Problem summary:
Snapshot of each SegmentReadTask will be released after FetchDisaggPages is called. But for some segments with no ColumnFileTiny or ColumnFileInMemory to fetch, FetchDisaggPages will never be called.

What is changed and how it works?

1. In WN, release snapshots of SegmentReadTasks that do not have ColumnFileTiny and ColumnFileInMemory.
2. In CN, no matter all ColumnFileTinys and ColumnFileInMemorys are cached or not, call FetchDisaggPages to release snapshot in WN.

Notes:

• From v8.1.0, CN need to fetch ColumnFileTiny and ColumnFileInMemory.
• In v7.5.0, CN only need to fetch ColumnFileTiny.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
  • Run CH-Benchmark workload and check the snapshot metrics.
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Fix the issue that lifetime of read-snapshots in write-nodes may be longer than expected in disaggregated-mode.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JinheLin, Lloyd-Pottiger

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• OWNERS [JinheLin,Lloyd-Pottiger]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-08-13 07:55:26.940722737 +0000 UTC m=+254611.644192379: ☑️ agreed by JinheLin.
• 2024-08-13 07:58:05.319266959 +0000 UTC m=+254770.022736616: ☑️ agreed by Lloyd-Pottiger.

[Lloyd-Pottiger]

/run-all-tests

[JinheLin]

/run-unit-test