Added knobs for RocksDB reader/writer thread priorities.

[liquid-helium]

Replace this text with your description here...

Code-Reviewer Section

The general pull request guidelines can be found here.

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.

For Release-Branches

If this PR is made against a release-branch, please also check the following:

• [ ] This change/bugfix is a cherry-pick from the next younger branch (younger release-branch or main if this is the youngest branch)
• [ ] There is a good reason why this PR needs to go into a release branch and this reason is documented (either in the description above or in a linked GitHub issue)

[foundationdb-ci]

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

• Commit ID: 0b4484c70ea91460ae1b7c3aba90ace069a9256f
• Duration 0:09:52
• Result: :x: FAILED
• Error: reference not found for primary source and source version 0b4484c70ea91460ae1b7c3aba90ace069a9256f
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 0b4484c70ea91460ae1b7c3aba90ace069a9256f
• Duration 0:10:17
• Result: :x: FAILED
• Error: reference not found for primary source and source version 0b4484c70ea91460ae1b7c3aba90ace069a9256f
• 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: ae79972566ecfc42edbfeb213d1ffb50dfef61e2
• Duration 0:08:58
• Result: :x: FAILED
• Error: reference not found for primary source and source version ae79972566ecfc42edbfeb213d1ffb50dfef61e2
• 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: f3b7e7eea4065949b02f823b8f823c05a866b9da
• Duration 0:10:09
• Result: :x: FAILED
• Error: reference not found for primary source and source version f3b7e7eea4065949b02f823b8f823c05a866b9da
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: ae79972566ecfc42edbfeb213d1ffb50dfef61e2
• Duration 0:09:48
• Result: :x: FAILED
• Error: reference not found for primary source and source version ae79972566ecfc42edbfeb213d1ffb50dfef61e2
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: f3b7e7eea4065949b02f823b8f823c05a866b9da
• Duration 0:12:01
• Result: :x: FAILED
• Error: reference not found for primary source and source version f3b7e7eea4065949b02f823b8f823c05a866b9da
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[fdb-windows-ci]

Doxense CI Report for Windows 10

• Commit ID: 2e2c198df7a8cf658b9b86551755b03135bc3ce5
• Result: :heavy_check_mark: SUCCEEDED
• Build Logs (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 2e2c198df7a8cf658b9b86551755b03135bc3ce5
• Duration 1:01:19
• Result: :x: FAILED
• Error: Error while executing command: if python3 -m joshua.joshua list --stopped | grep ${ENSEMBLE_ID} | grep -q 'pass=10[0-9][0-9][0-9]'; then echo PASS; else echo FAIL && 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: 2e2c198df7a8cf658b9b86551755b03135bc3ce5
• Duration 2:43:57
• 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)

[jzhou77]

Can you please resolve the conflict?

[foundationdb-ci]

Result of foundationdb-pr-clang-ide on Linux CentOS 7

• Commit ID: 3a15f4cf552b96e5597e7e8f97707b27b289befb
• Duration 0:19:11
• Result: :x: FAILED
• Error: Error while executing command: ninja -v -C build_output -j ${NPROC} all. Reason: exit status 1
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-clang on Linux CentOS 7

• Commit ID: 3a15f4cf552b96e5597e7e8f97707b27b289befb
• Duration 0:30:46
• Result: :x: FAILED
• Error: Error while executing command: if python3 -m joshua.joshua list --stopped | grep ${ENSEMBLE_ID} | grep -q 'pass=10[0-9][0-9][0-9]'; then echo PASS; else echo FAIL && 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 on Linux CentOS 7

• Commit ID: 3a15f4cf552b96e5597e7e8f97707b27b289befb
• Duration 0:31:17
• Result: :x: FAILED
• Error: Error while executing command: if python3 -m joshua.joshua list --stopped | grep ${ENSEMBLE_ID} | grep -q 'pass=10[0-9][0-9][0-9]'; then echo PASS; else echo FAIL && exit 1; fi. Reason: exit status 1
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[fdb-windows-ci]

Doxense CI Report for Windows 10

• Commit ID: 3a15f4cf552b96e5597e7e8f97707b27b289befb
• Result: :heavy_check_mark: SUCCEEDED
• Build Logs (available for 30 days)

[foundationdb-ci]

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

• Commit ID: 3a15f4cf552b96e5597e7e8f97707b27b289befb
• Duration 1:57:27
• 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)