rocksdb/include
Levi Tamasi 9e3ace42a4 Add statistics for BlobDB GC (#6296)
Summary:
The patch adds statistics support to the new BlobDB garbage collection implementation;
namely, it adds support for the following (pre-existing) tickers:

`BLOB_DB_GC_NUM_FILES`: the number of blob files obsoleted by the GC logic.
`BLOB_DB_GC_NUM_NEW_FILES`: the number of new blob files generated by the GC logic.
`BLOB_DB_GC_FAILURES`: the number of failed GC passes (where a GC pass is
equivalent to a (sub)compaction).
`BLOB_DB_GC_NUM_KEYS_RELOCATED`: the number of blobs relocated to new blob
files by the GC logic.
`BLOB_DB_GC_BYTES_RELOCATED`: the total size of blobs relocated to new blob files.

The tickers `BLOB_DB_GC_NUM_KEYS_OVERWRITTEN`, `BLOB_DB_GC_NUM_KEYS_EXPIRED`,
`BLOB_DB_GC_BYTES_OVERWRITTEN`, `BLOB_DB_GC_BYTES_EXPIRED`, and
`BLOB_DB_GC_MICROS` are not relevant for the new GC logic, and are thus marked
deprecated.

The patch also adds a couple of log messages that log the number and total size of
blobs encountered and relocated during a GC pass, as well as the number of blob
files created and obsoleted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6296

Test Plan: Extended unit tests and used the BlobDB mode of `db_bench`.

Differential Revision: D19402513

Pulled By: ltamasi

fbshipit-source-id: d53d2bfbf4928a1db1e9346c67ebb9007b8932ec
2020-01-29 16:46:16 -08:00
..
rocksdb Add statistics for BlobDB GC (#6296) 2020-01-29 16:46:16 -08:00