Revision d3d20dcdca9dc79d893a03dfa611fb1055c28f96 authored by Sagar Vemuri on 11 April 2019, 02:24:25 UTC, committed by Facebook Github Bot on 11 April 2019, 02:31:18 UTC
Summary:
Introducing Periodic Compactions.

This feature allows all the files in a CF to be periodically compacted. It could help in catching any corruptions that could creep into the DB proactively as every file is constantly getting re-compacted.  And also, of course, it helps to cleanup data older than certain threshold.

- Introduced a new option `periodic_compaction_time` to control how long a file can live without being compacted in a CF.
- This works across all levels.
- The files are put in the same level after going through the compaction. (Related files in the same level are picked up as `ExpandInputstoCleanCut` is used).
- Compaction filters, if any, are invoked as usual.
- A new table property, `file_creation_time`, is introduced to implement this feature. This property is set to the time at which the SST file was created (and that time is given by the underlying Env/OS).

This feature can be enabled on its own, or in conjunction with `ttl`. It is possible to set a different time threshold for the bottom level when used in conjunction with ttl. Since `ttl` works only on 0 to last but one levels, you could set `ttl` to, say, 1 day, and `periodic_compaction_time` to, say, 7 days. Since `ttl < periodic_compaction_time` all files in last but one levels keep getting picked up based on ttl, and almost never based on periodic_compaction_time. The files in the bottom level get picked up for compaction based on `periodic_compaction_time`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5166

Differential Revision: D14884441

Pulled By: sagar0

fbshipit-source-id: 408426cbacb409c06386a98632dcf90bfa1bda47
1 parent ef0fc1b
History
File Mode Size
.gitignore -rw-r--r-- 200 bytes
Makefile -rw-r--r-- 2.5 KB
README.md -rw-r--r-- 120 bytes
c_simple_example.c -rw-r--r-- 2.6 KB
column_families_example.cc -rw-r--r-- 1.9 KB
compact_files_example.cc -rw-r--r-- 5.7 KB
compaction_filter_example.cc -rw-r--r-- 2.9 KB
multi_processes_example.cc -rw-r--r-- 11.7 KB
optimistic_transaction_example.cc -rw-r--r-- 4.1 KB
options_file_example.cc -rw-r--r-- 4.0 KB
rocksdb_option_file_example.ini -rw-r--r-- 4.6 KB
simple_example.cc -rw-r--r-- 2.4 KB
transaction_example.cc -rw-r--r-- 4.1 KB

README.md

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