Add test showing range tombstones can create excessively large compactions #5956
Conversation
There was a problem hiding this comment.
@dlambrig has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
|
@dlambrig has updated the pull request. Re-import the pull request |
There was a problem hiding this comment.
@dlambrig has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
There was a problem hiding this comment.
@dlambrig has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
There was a problem hiding this comment.
@dlambrig has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
There was a problem hiding this comment.
@dlambrig has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
There was a problem hiding this comment.
@dlambrig has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
…tions (facebook#5956) Summary: For more information on the original problem see this [link](facebook#3977). This change adds two new tests. They are identical other than one uses range tombstones and the other does not. Each test generates sub files at L2 which overlap with keys L3. The test that uses range tombstones generates a single file at L2. This single file will generate a very large range overlap that will in turn create excessively large compaction. 1: T001 - T005 2: 000 - 005 In contrast, the test that uses key ranges generates 3 files at L2. As a single file is compacted at a time, those 3 files will generate less work per compaction iteration. 1: 001 - 002 1: 003 - 004 1: 005 2: 000 - 005 Pull Request resolved: facebook#5956 Differential Revision: D18071631 Pulled By: dlambrig fbshipit-source-id: 12abae75fb3e0b022d228c6371698aa5e53385df
For more information on the original problem see this link.
This change adds two new tests. They are identical other than one uses range tombstones and the other does not. Each test generates sub files at L2 which overlap with keys L3. The test that uses range tombstones generates a single file at L2. This single file will generate a very large range overlap that will in turn create excessively large compaction.
1: T001 - T005
2: 000 - 005
In contrast, the test that uses key ranges generates 3 files at L2. As a single file is compacted at a time, those 3 files will generate less work per compaction iteration.
1: 001 - 002
1: 003 - 004
1: 005
2: 000 - 005