Added RocksDB latency samples and priority knobs.

[liquid-helium]

Added RocksDB latency samples, and server knobs to tune RocksDB read/write thread priority.

main branch pr: #8236

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Please check each of the following things and check all boxes before accepting a PR.

• [ ] The PR has a description, explaining both the problem and the solution.
• [ ] The description mentions which forms of testing were done and the testing seems reasonable.
• [ ] Every function/class/actor that was touched is reasonably well documented.

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• [ ] This change/bugfix is a cherry-pick from the next younger branch (younger release-branch or main if this is the youngest branch)
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[fdb-windows-ci]

Doxense CI Report for Windows 10

• Commit ID: 4c137f8be86060dcef12a24e32270129f4933a5d
• Result: :heavy_check_mark: SUCCEEDED
• Build Logs (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 4c137f8be86060dcef12a24e32270129f4933a5d
• Duration 1:00:02
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-cluster-tests on Linux CentOS 7

• Commit ID: 4c137f8be86060dcef12a24e32270129f4933a5d
• Duration 1:49:47
• Result: :x: FAILED
• Error: Error while executing command: if $(grep -q -- "--- FAIL:" ${CODEBUILD_SRC_DIR}/fdb-kubernetes-tests/logs/*.log); then echo "TESTS FAILED SEE THESE LOGS:"; echo ; grep -l -- "--- FAIL:" ${CODEBUILD_SRC_DIR}/fdb-kubernetes-tests/logs/*.log; exit 1; fi. Reason: exit status 1
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-cluster-tests on Linux CentOS 7

• Commit ID: 81dbf61bc8a929f67de06999addab0ec68575f00
• Duration 0:10:05
• Result: :x: FAILED
• Error: reference not found for primary source and source version 81dbf61bc8a929f67de06999addab0ec68575f00
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 81dbf61bc8a929f67de06999addab0ec68575f00
• Duration 0:11:57
• Result: :x: FAILED
• Error: reference not found for primary source and source version 81dbf61bc8a929f67de06999addab0ec68575f00
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 4c137f8be86060dcef12a24e32270129f4933a5d
• Duration 1:02:22
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-cluster-tests on Linux CentOS 7

• Commit ID: 4c137f8be86060dcef12a24e32270129f4933a5d
• Duration 1:44:20
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-macos on macOS BigSur 11.5.2

• Commit ID: 4c137f8be86060dcef12a24e32270129f4933a5d
• Duration 0:37:02
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)