ARCHIVE/rippled
1
0
Fork 0
mirror of https://github.com/XRPLF/rippled.git synced 2025-12-06 17:27:55 +00:00
Code Issues Packages Projects Releases Wiki Activity

Added a parameter to limit the maximum space amplification for universal compaction.

Browse Source 
Summary:
Added a new field called max_size_amplification_ratio in the
CompactionOptionsUniversal structure. This determines the maximum
percentage overhead of space amplification.

The size amplification is defined to be the ratio between the size of
the oldest file to the sum of the sizes of all other files. If the
size amplification exceeds the specified value, then min_merge_width
and max_merge_width are ignored and a full compaction of all files is done.
A value of 10 means that the size a database that stores 100 bytes
of user data could occupy 110 bytes of physical storage.

Test Plan: Unit test DBTest.UniversalCompactionSpaceAmplification added.

Reviewers: haobo, emayanke, xjin

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12825
This commit is contained in:
Dhruba Borthakur
2013-09-09 16:06:10 -07:00
parent e2a093a6c3
commit 4012ca1c7b
7 changed files with 381 additions and 133 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
include/rocksdb/universal_compaction.h
View File

@@ -36,9 +36,21 @@ class CompactionOptionsUniversal {
// The minimum number of files in a single compaction run. Default: 2
unsigned int min_merge_width;
// The maximum number of files in a single compaction run. Default: INT_MAX
// The maximum number of files in a single compaction run. Default: UINT_MAX
unsigned int max_merge_width;
// The size amplification is defined as the amount (in percentage) of
// additional storage needed to store a single byte of data in the database.
// For example, a size amplification of 2% means that a database that
// contains 100 bytes of user-data may occupy upto 102 bytes of
// physical storage. By this definition, a fully compacted database has
// a size amplification of 0%. Rocksdb uses the following heuristic
// to calculate size amplification: it assumes that all files excluding
// the earliest file contribute to the size amplification.
// Default: 200, which means that a 100 byte database could require upto
// 300 bytes of storage.
unsigned int max_size_amplification_percent;
// The algorithm used to stop picking files into a single compaction run
// Default: kCompactionStopStyleTotalSize
CompactionStopStyle stop_style;
@@ -48,6 +60,7 @@ class CompactionOptionsUniversal {
size_ratio(1),
min_merge_width(2),
max_merge_width(UINT_MAX),
max_size_amplification_percent(200),
stop_style(kCompactionStopStyleTotalSize) {
}
};