mirror of https://github.com/facebook/rocksdb.git
51a8dc6d14
Summary: The patch adds basic garbage collection support to the integrated BlobDB implementation. Valid blobs residing in the oldest blob files are relocated as they are encountered during compaction. The threshold that determines which blob files qualify is computed based on the configuration option `blob_garbage_collection_age_cutoff`, which was introduced in https://github.com/facebook/rocksdb/issues/7661 . Once a blob is retrieved for the purposes of relocation, it passes through the same logic that extracts large values to blob files in general. This means that if, for instance, the size threshold for key-value separation (`min_blob_size`) got changed or writing blob files got disabled altogether, it is possible for the value to be moved back into the LSM tree. In particular, one way to re-inline all blob values if needed would be to perform a full manual compaction with `enable_blob_files` set to `false`, `enable_blob_garbage_collection` set to `true`, and `blob_file_garbage_collection_age_cutoff` set to `1.0`. Some TODOs that I plan to address in separate PRs: 1) We'll have to measure the amount of new garbage in each blob file and log `BlobFileGarbage` entries as part of the compaction job's `VersionEdit`. (For the time being, blob files are cleaned up solely based on the `oldest_blob_file_number` relationships.) 2) When compression is used for blobs, the compression type hasn't changed, and the blob still qualifies for being written to a blob file, we can simply copy the compressed blob to the new file instead of going through decompression and compression. 3) We need to update the formula for computing write amplification to account for the amount of data read from blob files as part of GC. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7694 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D25069663 Pulled By: ltamasi fbshipit-source-id: bdfa8feb09afcf5bca3b4eba2ba72ce2f15cd06a |
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| .. | ||
| compaction.cc | ||
| compaction.h | ||
| compaction_iteration_stats.h | ||
| compaction_iterator.cc | ||
| compaction_iterator.h | ||
| compaction_iterator_test.cc | ||
| compaction_job.cc | ||
| compaction_job.h | ||
| compaction_job_stats_test.cc | ||
| compaction_job_test.cc | ||
| compaction_picker.cc | ||
| compaction_picker.h | ||
| compaction_picker_fifo.cc | ||
| compaction_picker_fifo.h | ||
| compaction_picker_level.cc | ||
| compaction_picker_level.h | ||
| compaction_picker_test.cc | ||
| compaction_picker_universal.cc | ||
| compaction_picker_universal.h | ||
| sst_partitioner.cc | ||