mirror of https://github.com/facebook/rocksdb.git
d010b02e86
Summary: In follow-up to https://github.com/facebook/rocksdb/issues/11922, fix a race in functions like CreateColumnFamily and SetDBOptions where the DB reports one option setting but a different one is left in effect. To fix, we can add an extra mutex around these rare operations. We don't want to hold the DB mutex during I/O or other slow things because of the many purposes it serves, but a mutex more limited to these cases should be fine. I believe this would fix a write-write race in https://github.com/facebook/rocksdb/issues/10079 but not the read-write race. Intended follow-up to this: * Should be able to remove write thread synchronization from DBImpl::WriteOptionsFile Pull Request resolved: https://github.com/facebook/rocksdb/pull/11929 Test Plan: Added two mini-stress style regression tests that fail with >1% probability before this change: DBOptionsTest::SetStatsDumpPeriodSecRace ColumnFamilyTest::CreateAndDropPeriodicRace I haven't reproduced such an inconsistency between in-memory options and on disk latest options, but this change at least improves safety and adds a test anyway: DBOptionsTest::SetStatsDumpPeriodSecRace Reviewed By: ajkr Differential Revision: D50024506 Pulled By: pdillinger fbshipit-source-id: 1e99a9ed4d96fdcf3ac5061ec6b3cee78aecdda4 |
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| behavior_changes | ||
| bug_fixes | ||
| new_features | ||
| performance_improvements | ||
| public_api_changes | ||
| README.txt | ||
| add.sh | ||
| release.sh | ||
README.txt
Adding release notes -------------------- When adding release notes for the next release, add a file to one of these directories: unreleased_history/new_features unreleased_history/behavior_changes unreleased_history/public_api_changes unreleased_history/bug_fixes with a unique name that makes sense for your change, preferably using the .md extension for syntax highlighting. There is a script to help, as in $ unreleased_history/add.sh unreleased_history/bug_fixes/crash_in_feature.md or simply $ unreleased_history/add.sh will take you through some prompts. The file should usually contain one line of markdown, and "* " is not required, as it will automatically be inserted later if not included at the start of the first line in the file. Extra newlines or missing trailing newlines will also be corrected. The only times release notes should be added directly to HISTORY are if * A release is being amended or corrected after it is already "cut" but not tagged, which should be rare. * A single commit contains a noteworthy change and a patch release version bump Ordering of entries ------------------- Within each group, entries will be included using ls sort order, so important entries could start their file name with a small three digit number like 100pretty_important.md. The ordering of groups such as new_features vs. public_api_changes is hard-coded in unreleased_history/release.sh Updating HISTORY.md with release notes -------------------------------------- The script unreleased_history/release.sh does this. Run the script before updating version.h to the next develpment release, so that the script will pick up the version being released. You might want to start with $ DRY_RUN=1 unreleased_history/release.sh | less to check for problems and preview the output. Then run $ unreleased_history/release.sh which will git rm some files and modify HISTORY.md. You still need to commit the changes, or revert with the command reported in the output. Why not update HISTORY.md directly? ----------------------------------- First, it was common to hit unnecessary merge conflicts when adding entries to HISTORY.md, which slowed development. Second, when a PR was opened before a release cut and landed after the release cut, it was easy to add the HISTORY entry to the wrong version's history. This new setup completely fixes both of those issues, with perhaps slighly more initial work to create each entry. There is also now an extra step in using `git blame` to map a release note to its source code implementation, but that is a relatively rare operation.