sst_dump to reduce number of file reads #6836
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Summary: sst_dump can issue many file reads from the file system. This doesn't work well with file systems without a OS cache, especially remote file systems. In order to mitigate this problem, several improvements are done: 1. --readahead_size is added, so that users can specify readahead size when scanning the data. 2. Force a 512KB tail readahead, which prevents three I/Os for footer, meta index and property blocks and hopefully index and filter blocks too. 3. Consoldiate SSTDump's I/Os before opening the file for read. Use the same file prefetch buffer. Test Plan: Add a test that covers this new feature.
There was a problem hiding this comment.
@siying 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.
@siying has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
pdillinger
approved these changes
May 12, 2020
| // To force tail prefetching, we directly tail tail prefetching to | ||
| // read 512KB blocks. | ||
| bbtf->tail_prefetch_stats()->RecordEffectiveSize(512 * 1024); | ||
| bbtf->tail_prefetch_stats()->RecordEffectiveSize(512 * 1024); |
There was a problem hiding this comment.
Yes. The stats only start to kick in after two.
tools/sst_dump_tool.cc
Outdated
| @@ -318,8 +337,15 @@ Status SstFileDumper::SetTableOptionsByMagicNumber( | |||
| assert(table_properties_); | |||
| if (table_magic_number == kBlockBasedTableMagicNumber || | |||
| table_magic_number == kLegacyBlockBasedTableMagicNumber) { | |||
| options_.table_factory = std::make_shared<BlockBasedTableFactory>(); | |||
| BlockBasedTableFactory* bbtf = new BlockBasedTableFactory(); | |||
| // To force tail prefetching, we directly tail tail prefetching to | |||
|
And of course fixing Windows and MacOS build errors |
|
@siying has updated the pull request. Re-import the pull request |
There was a problem hiding this comment.
@siying has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
|
This pull request has been merged in 4a4b8a1. |
levichen94
pushed a commit
to bytedance/terarkdb
that referenced
this pull request
Jun 18, 2021
Summary: sst_dump can issue many file reads from the file system. This doesn't work well with file systems without a OS cache, especially remote file systems. In order to mitigate this problem, several improvements are done: 1. --readahead_size is added, so that users can specify readahead size when scanning the data. 2. Force a 512KB tail readahead, which prevents three I/Os for footer, meta index and property blocks and hopefully index and filter blocks too. 3. Consoldiate SSTDump's I/Os before opening the file for read. Use the same file prefetch buffer. Pull Request resolved: facebook/rocksdb#6836 Test Plan: Add a test that covers this new feature. Reviewed By: pdillinger Differential Revision: D21516607 fbshipit-source-id: 3ae43526286f67b2f4a5bdedfbc92719d579b87e Signed-off-by: Changlong Chen <levisonchen@live.cn>
mm304321141
pushed a commit
to bytedance/terarkdb
that referenced
this pull request
Jun 23, 2021
Summary: sst_dump can issue many file reads from the file system. This doesn't work well with file systems without a OS cache, especially remote file systems. In order to mitigate this problem, several improvements are done: 1. --readahead_size is added, so that users can specify readahead size when scanning the data. 2. Force a 512KB tail readahead, which prevents three I/Os for footer, meta index and property blocks and hopefully index and filter blocks too. 3. Consoldiate SSTDump's I/Os before opening the file for read. Use the same file prefetch buffer. Pull Request resolved: facebook/rocksdb#6836 Test Plan: Add a test that covers this new feature. Reviewed By: pdillinger Differential Revision: D21516607 fbshipit-source-id: 3ae43526286f67b2f4a5bdedfbc92719d579b87e Signed-off-by: Changlong Chen <levisonchen@live.cn>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary: sst_dump can issue many file reads from the file system. This doesn't work well with file systems without a OS cache, especially remote file systems. In order to mitigate this problem, several improvements are done:
Test Plan: Add a test that covers this new feature.