rocksdb/unreleased_history
akankshamahajan c1a97fe1f6 Fix Assertion `roundup_len2 >= alignment' failed in crash tests (#11852)
Summary:
When auto_readahead_size is enabled in async_io, during seek, first buffer will prefetch the data - (current block + readahead till upper_bound). There can be cases where
1.  first buffer prefetched all the data till upper bound, or
2.  first buffer already has the data from prev seek call
and second buffer prefetch further leading to alignment issues.

This PR fixes that assertion and second buffer won't go for prefetching if first buffer has already prefetched till upper_bound.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11852

Test Plan:
- Added new unit test that failed without this fix.
- crash tests passed locally

Reviewed By: pdillinger

Differential Revision: D49384138

Pulled By: akankshamahajan15

fbshipit-source-id: 54417e909e4d986f1e5a17dbaea059cd4962fd4d
2023-09-20 16:13:20 -07:00
..
behavior_changes Conditionally exclude some L0 input files in size amp compaction (#11749) 2023-09-12 15:53:15 -07:00
bug_fixes Fix Assertion `roundup_len2 >= alignment' failed in crash tests (#11852) 2023-09-20 16:13:20 -07:00
new_features Release note for #11738 AutoHCC (#11855) 2023-09-19 11:35:43 -07:00
performance_improvements Avoid double block cache lookup during Seek with async_io option (#11616) 2023-09-18 11:32:30 -07:00
public_api_changes Expose more info about input files in CompactionFilter::Context (#11857) 2023-09-20 13:34:39 -07:00
add.sh Some fixes to unreleased_history/ (#11504) 2023-06-02 15:55:02 -07:00
README.txt Better management of unreleased HISTORY (#11481) 2023-05-30 16:42:49 -07:00
release.sh Update for 8.5.fb branch cut (#11642) 2023-08-02 12:34:11 -07:00

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.