Commit Graph

196 Commits

Author SHA1 Message Date
Yueh-Hsuan Chiang
faa8d21922 Improve an assertion in RandomGenerator::Generate() in db_bench.
Summary:
RandomGenerator::Generate() currently has an assertion len < data_.size().
However, it is actually fine to have len == data_.size().
This diff change the assertion to len <= data_.size().

Test Plan:
make db_bench
./db_bench

Reviewers: haobo, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19269
2014-06-24 15:29:28 -06:00
Lei Jin
3b0dc76699 db_bench: measure the real latency of write/delete
Summary: as title

Test Plan: make release

Reviewers: haobo, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19227
2014-06-23 13:23:02 -07:00
Lei Jin
a1b5650a75 db_bench: sanity check on compression ratio
Summary: as requested by mark

Test Plan: make release

Reviewers: sdong, haobo

Reviewed By: haobo

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19221
2014-06-23 10:46:16 -07:00
Igor Canadi
d4a8423334 Remove seek compaction
Summary:
As discussed in our internal group, we don't get much use of seek compaction at the moment, while it's making code more complicated and slower in some cases.

This diff removes seek compaction and (hopefully) all code that was introduced to support seek compaction.

There is one test case that relied on didIO information. I'll try to find another way to implement it.

Test Plan: make check

Reviewers: sdong, haobo, yhchiang, ljin, dhruba

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19161
2014-06-20 10:23:02 +02:00
Lei Jin
388d2054c7 forward iterator
Summary:
Forward iterator puts everything together in a flat structure instead of
a hierarchy of nested iterators. this should simplify the code and
provide better performance. It also enables more optimization since all
information are accessiable in one place.
Init evaluation shows about 6% improvement

Test Plan: db_test and db_bench

Reviewers: dhruba, igor, tnovak, sdong, haobo

Reviewed By: haobo

Subscribers: sdong, leveldb

Differential Revision: https://reviews.facebook.net/D18795
2014-05-30 14:31:55 -07:00
Lei Jin
f29c62fc6f add an iterator refresh option for SeekRandom
Summary: One more option to allow iterator refreshing when using normal iterator

Test Plan: ran db_bench

Reviewers: haobo, sdong, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D18849
2014-05-30 14:09:22 -07:00
sdong
4e0602f941 Remove maximum key_size check in db_bench
Summary: Key size limit doesn't seem to be applicable anymore. Remove it.

Test Plan: run a couple of tests in db_bench

Reviewers: haobo, igor, yhchiang, dhruba

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18723
2014-05-15 11:06:37 -07:00
Igor Canadi
a1068c91a1 Make RocksDB work with newer gflags
Summary:
Newer gflags switched from `google` namespace to `gflags` namespace. See: https://github.com/facebook/rocksdb/issues/139 and https://github.com/facebook/rocksdb/issues/102

Unfortunately, they don't define any macro with their namespace, so we need to actually try to compile gflags with two different namespace to figure out which one is the correct one.

Test Plan: works in fbcode environemnt. I'll also try in ubutnu with newer gflags

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18537
2014-05-08 17:25:13 -07:00
Igor Canadi
0afc8bc29a xxHash
Summary:
Originally: https://github.com/facebook/rocksdb/pull/87/files

I'm taking over to apply some finishing touches

Test Plan: will add tests

Reviewers: dhruba, haobo, sdong, yhchiang, ljin

Reviewed By: yhchiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18315
2014-05-01 14:09:32 -04:00
Yueh-Hsuan Chiang
9d9d2965cb Add a new mem-table representation based on cuckoo hash.
Summary:
= Major Changes =
* Add a new mem-table representation, HashCuckooRep, which is based cuckoo hash.
  Cuckoo hash uses multiple hash functions.  This allows each key to have multiple
  possible locations in the mem-table.

  - Put: When insert a key, it will try to find whether one of its possible
    locations is vacant and store the key.  If none of its possible
    locations are available, then it will kick out a victim key and
    store at that location.  The kicked-out victim key will then be
    stored at a vacant space of its possible locations or kick-out
    another victim.  In this diff, the kick-out path (known as
    cuckoo-path) is found using BFS, which guarantees to be the shortest.

 - Get: Simply tries all possible locations of a key --- this guarantees
   worst-case constant time complexity.

 - Time complexity: O(1) for Get, and average O(1) for Put if the
   fullness of the mem-table is below 80%.

 - Default using two hash functions, the number of hash functions used
   by the cuckoo-hash may dynamically increase if it fails to find a
   short-enough kick-out path.

 - Currently, HashCuckooRep does not support iteration and snapshots,
   as our current main purpose of this is to optimize point access.

= Minor Changes =
* Add IsSnapshotSupported() to DB to indicate whether the current DB
  supports snapshots.  If it returns false, then DB::GetSnapshot() will
  always return nullptr.

Test Plan:
Run existing tests.  Will develop a test specifically for cuckoo hash in
the next diff.

Reviewers: sdong, haobo

Reviewed By: sdong

CC: leveldb, dhruba, igor

Differential Revision: https://reviews.facebook.net/D16155
2014-04-29 17:13:46 -07:00
Igor Canadi
38693d99c4 Fix more signed/unsigned comparsions 2014-04-29 12:40:18 -07:00
Lei Jin
3995e801ab kill ReadOptions.prefix and .prefix_seek
Summary:
also add an override option total_order_iteration if you want to use full
iterator with prefix_extractor

Test Plan: make all check

Reviewers: igor, haobo, sdong, yhchiang

Reviewed By: haobo

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D17805
2014-04-25 12:21:34 -07:00
Igor Canadi
f9f8965e96 Print out stack trace in mac, too
Summary: While debugging Mac-only issue with ThreadLocalPtr, this was very useful. Let's print out stack trace in MAC OS, too.

Test Plan: Verified that somewhat useful stack trace was generated on mac. Will run PrintStack() on linux, too.

Reviewers: ljin, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18189
2014-04-23 09:11:35 -04:00
Igor Canadi
8dc34364d2 Rename "benchmark" back to "bench".
Also, make `benchharness.cc` not compiled into rocksdb library.
2014-04-21 13:12:15 -07:00
Pratyush Seth
ff1b5df4c6 Added benchmark functionality on the lines of folly/Benchmark.h
Summary: Added benchmark functionality on the lines of folly/Benchmark.h

Test Plan: Added unit tests

Reviewers: igor, haobo, sdong, ljin, yhchiang, dhruba

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17973
2014-04-21 12:29:55 -07:00
sdong
c87ed0942c Fix db_bench's multireadrandom
Summary: multireadrandom is broken. Fix it

Test Plan: run it and see segfault has gone.

Reviewers: ljin

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17781
2014-04-14 15:43:34 -07:00
sdong
d5e087b6df db_bench: add a mode to operate multiple DBs
Summary: This patch introduces a new parameter num_multi_db in db_bench. When this parameter is larger than 1, multiple DBs will be created. In all benchmarks, any operation applies to a random DB among them. This is to benchmark the performance of similar applications.

Test Plan: run db_bench on both of num_multi_db=0 and more.

Reviewers: haobo, ljin, igor

Reviewed By: igor

CC: igor, yhchiang, dhruba, nkg-, leveldb

Differential Revision: https://reviews.facebook.net/D17769
2014-04-11 16:59:08 -07:00
Lei Jin
0af36d6aa6 SeekRandomWhileWriting
Summary: as title

Test Plan: ran it

Reviewers: igor, haobo, yhchiang

Reviewed By: yhchiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17751
2014-04-11 09:47:20 -07:00
Lei Jin
7a92537fc4 db_bench: add IteratorCreationWhileWriting mode and allow prefix_seek
Summary: as title

Test Plan: ran it

Reviewers: igor, haobo, yhchiang

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17655
2014-04-10 10:15:59 -07:00
Igor Canadi
4daea66343 Turn on -Wmissing-prototypes
Summary: Compiling for iOS has by default turned on -Wmissing-prototypes, which causes rocksdb to fail compiling. This diff turns on -Wmissing-prototypes in our compile options and cleans up all functions with missing prototypes.

Test Plan: compiles

Reviewers: dhruba, haobo, ljin, sdong

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17649
2014-04-09 21:17:14 -07:00
Lei Jin
4824014e3b speed up db_bench filluniquerandom mode
Summary:
filluniquerandom is painfully slow due to the naive bitmap check to find
out if a key has been seen before. Majority of time is spent on searching
the last few keys. Split a giant BitSet to smaller ones so that we can
quickly check if a BitSet is full and thus can skip quickly.

It used to take over one hour to filluniquerandom for 100M keys, now it
takes about 10 mins.

Test Plan:
unit test
also verified correctness in db_bench and make sure all keys are
generated

Reviewers: igor, haobo, yhchiang

Reviewed By: igor

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D17607
2014-04-09 11:25:21 -07:00
Igor Canadi
34455deb06 Fix Mac OS compile issues 2014-04-08 14:05:53 -07:00
Lei Jin
0c1126d4cf db_bench cleanup
Summary:
clean up the db_bench a little bit. also avoid allocating memory for key
in the loop

Test Plan:
I verified a run with filluniquerandom & readrandom. Iterator seek will be used lot
to measure performance. Will fix whatever comes up

Reviewers: haobo, igor, yhchiang

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17559
2014-04-08 11:21:09 -07:00
Lei Jin
c90d446ee7 make hash_link_list Node's key space consecutively followed at the end
Summary: per sdong's request, this will help processor prefetch on n->key case.

Test Plan: make all check

Reviewers: sdong, haobo, igor

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17415
2014-04-04 15:37:28 -07:00
Lei Jin
0d755fff14 cache friendly blocked bloomfilter
Summary:
By constraining the probes within cache line(s), we can improve the
cache miss rate thus performance. This probably only makes sense for
in-memory workload so defaults the option to off.

Numbers and comparision can be found in wiki:
https://our.intern.facebook.com/intern/wiki/index.php/Ljin/rocksdb_perf/2014_03_17#Bloom_Filter_Study

Test Plan: benchmarked this change substantially. Will run make all check as well

Reviewers: haobo, igor, dhruba, sdong, yhchiang

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17133
2014-03-28 09:21:20 -07:00
Lei Jin
8d007b4aaf Consolidate SliceTransform object ownership
Summary:
(1) Fix SanitizeOptions() to also check HashLinkList. The current
dynamic case just happens to work because the 2 classes have the same
layout.
(2) Do not delete SliceTransform object in HashSkipListFactory and
HashLinkListFactory destructor. Reason: SanitizeOptions() enforces
prefix_extractor and SliceTransform to be the same object when
Hash**Factory is used. This makes the behavior strange: when
Hash**Factory is used, prefix_extractor will be released by RocksDB. If
other memtable factory is used, prefix_extractor should be released by
user.

Test Plan: db_bench && make asan_check

Reviewers: haobo, igor, sdong

Reviewed By: igor

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D16587
2014-03-10 12:56:46 -07:00
Lei Jin
04298f8c33 output perf_context in db_bench readrandom
Summary:
Add helper function to print perf context data in db_bench if enabled.
I didn't find any code that actually exports perf context data. Not sure
if I missed anything

Test Plan: ran db_bench

Reviewers: haobo, sdong, igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16575
2014-03-05 10:32:54 -08:00
Lei Jin
64138b5d9c fix db_bench to use HashSkipList for real
Summary:
For HashSkipList case, DBImpl has sanity check to see if prefix_extractor in
options is the same as the one in memtable factory. If not, it falls
back to SkipList. As result, I was experimenting with SkipList
performance. No wonder it is much worse than LinkedList

Test Plan: ran benchmark

Reviewers: haobo, sdong, igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16569
2014-03-05 10:28:53 -08:00
Lei Jin
51560ba755 config max_background_flushes in db_bench
Summary: as title

Test Plan: make release

Reviewers: haobo, sdong, igor

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16437
2014-03-05 10:27:17 -08:00
Lei Jin
a5b1d2f146 make key evenly distributed between 0 and FLAGS_num
Summary:
The issue is that when FLAGS_num is small, the leading bytes of the key
are padded with 0s. This makes all keys have the same prefix 00000000

Most of the changes are just to make lint happy

Test Plan: ran db_bench

Reviewers: sdong, haobo, igor

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16317
2014-03-04 17:08:05 -08:00
Lei Jin
dea894ef8d expose wal_dir in db_bench
Summary: as title

Test Plan: ran db_bench

Reviewers: dhruba, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16269
2014-02-25 10:43:46 -08:00
Lei Jin
28b7f7faa8 enable plain table in db_bench
Summary: as title

Test Plan: ran db_bench to gather stats

Reviewers: haobo, sdong

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16059
2014-02-12 10:41:55 -08:00
Albert Strasheim
df2f92214a Support for LZ4 compression. 2014-02-08 14:15:51 -08:00
Igor Canadi
1560bb913e Readrandom with tailing iterator
Summary:
Added an option for readrandom benchmark to run with tailing iterator instead of Get. Benefit of tailing iterator is that it doesn't require locking DB mutex on access.

I also have some results when running on my machine. The results highly depend on number of cache shards. With our current benchmark setting of 4 table cache shards and 6 block cache shards, I don't see much improvements of using tailing iterator. In that case, we're probably seeing cache mutex contention.

Here are the results for different number of shards

    cache shards       tailing iterator        get
       6                      1.38M           1.16M
      10                      1.58M           1.15M

As soon as we get rid of cache mutex contention, we're seeing big improvements in using tailing iterator vs. ordinary get.

Test Plan: ran regression test

Reviewers: dhruba, haobo, ljin, kailiu, sding

Reviewed By: haobo

CC: tnovak

Differential Revision: https://reviews.facebook.net/D15867
2014-02-07 09:47:47 -08:00
kailiu
84f8185fc0 Merge branch 'master' into performance
Conflicts:
	HISTORY.md
	db/db_impl.cc
	db/memtable.cc
2014-02-05 21:21:00 -08:00
Lei Jin
5b3b6549d6 use super_version in NewIterator() and MultiGet() function
Summary:
Use super_version insider NewIterator to avoid Ref() each component
separately under mutex
The new added bench shows NewIterator QPS increases from 515K to 719K
No meaningful improvement for multiget I guess due to its relatively small
cost comparing to 90 keys fetch in the test.

Test Plan: unit test and db_bench

Reviewers: igor, sdong

Reviewed By: igor

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D15609
2014-02-03 13:13:36 -08:00
Igor Canadi
5c6ef56152 Fix printf format 2014-02-03 10:25:37 -08:00
kailiu
a5e220f5ef Merge branch 'master' into performance
Conflicts:
	Makefile
	db/db_impl.cc
	db/db_test.cc
	db/memtable_list.cc
	db/memtable_list.h
	table/block_based_table_reader.cc
	table/table_test.cc
	util/cache.cc
	util/coding.cc
2014-01-28 10:35:55 -08:00
Siying Dong
8477255da3 Moving Some includes from options.h to forward declaration
Summary: By removing some includes form options.h and reply on forward declaration, we can more easily reason the dependencies.

Test Plan: make all check

Reviewers: kailiu, haobo, igor, dhruba

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15411
2014-01-24 17:16:22 -08:00
Igor Canadi
e832e72b31 Revert "Moving to glibc-fb"
This reverts commit d24961b65e.

For some reason, glibc2.17-fb breaks gflags. Reverting for now
2014-01-24 11:50:38 -08:00
Igor Canadi
d24961b65e Moving to glibc-fb
Summary:
It looks like we might have some trouble when building the new release with 4.8, since fbcode is using glibc2.17-fb by default and we are using glibc2.17. It was reported by Benjamin Renard in our internal group.

This diff moves our fbcode build to use glibc2.17-fb by default. I got some linker errors when compiling, complaining that `google::SetUsageMessage()` was undefined. After deleting all offending lines, the compile was successful and everything works.

Test Plan:
Compiled
Ran ./db_bench ./db_stress ./db_repl_stress

Reviewers: kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15405
2014-01-24 10:24:08 -08:00
Kai Liu
054c5dda8c Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/db_test.cc
	db/memtable.cc
	db/version_set.cc
	include/rocksdb/statistics.h
	util/statistics_imp.h
2014-01-23 16:32:49 -08:00
Igor Canadi
83681bf9ef Statistics code cleanup
Summary: I'm separating code-cleanup part of https://reviews.facebook.net/D14517. This will make D14517 easier to understand and this diff easier to review.

Test Plan: make check

Reviewers: haobo, kailiu, sdong, dhruba, tnovak

Reviewed By: tnovak

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15099
2014-01-17 12:46:06 -08:00
kailiu
1304d8c8ce Merge branch 'master' into performance
Conflicts:
	Makefile
	db/db_impl.cc
	db/db_impl.h
	db/db_test.cc
	db/memtable.cc
	db/memtable.h
	db/version_edit.h
	db/version_set.cc
	include/rocksdb/options.h
	util/hash_skiplist_rep.cc
	util/options.cc
2014-01-15 23:12:31 -08:00
Schalk-Willem Kruger
a09ee1069d Improve RocksDB "get" performance by computing merge result in memtable
Summary:
Added an option (max_successive_merges) that can be used to specify the
maximum number of successive merge operations on a key in the memtable.
This can be used to improve performance of the "get" operation. If many
successive merge operations are performed on a key, the performance of "get"
operations on the key deteriorates, as the value has to be computed for each
"get" operation by applying all the successive merge operations.

FB Task ID: #3428853

Test Plan:
make all check
db_bench --benchmarks=readrandommergerandom
counter_stress_test

Reviewers: haobo, vamsi, dhruba, sdong

Reviewed By: haobo

CC: zshao

Differential Revision: https://reviews.facebook.net/D14991
2014-01-10 17:33:56 -08:00
kailiu
f1cec73a76 Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/db_test.cc
	db/memtable.cc
	db/version_set.cc
	include/rocksdb/statistics.h
2013-12-27 12:23:17 -08:00
Mark Callaghan
ca92068b12 Add 'readtocache' test
Summary:
For some tests I want to cache the database prior to running other tests on the same invocation
of db_bench. The readtocache test ignores --threads and --reads so those can be used by other tests
and it will still do a full read of --num rows with one thread. It might be invoked like:
  db_bench --benchmarks=readtocache,readrandom --reads 100 --num 10000 --threads 8

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14739
2013-12-18 16:54:53 -08:00
Mark Callaghan
e9e6b00d29 Add monitoring for universal compaction and add counters for compaction IO
Summary:
Adds these counters
{ WAL_FILE_SYNCED, "rocksdb.wal.synced" }
  number of writes that request a WAL sync
{ WAL_FILE_BYTES, "rocksdb.wal.bytes" },
  number of bytes written to the WAL
{ WRITE_DONE_BY_SELF, "rocksdb.write.self" },
  number of writes processed by the calling thread
{ WRITE_DONE_BY_OTHER, "rocksdb.write.other" },
  number of writes not processed by the calling thread. Instead these were
  processed by the current holder of the write lock
{ WRITE_WITH_WAL, "rocksdb.write.wal" },
  number of writes that request WAL logging
{ COMPACT_READ_BYTES, "rocksdb.compact.read.bytes" },
  number of bytes read during compaction
{ COMPACT_WRITE_BYTES, "rocksdb.compact.write.bytes" },
  number of bytes written during compaction

Per-interval stats output was updated with WAL stats and correct stats for universal compaction
including a correct value for write-amplification. It now looks like:
                               Compactions
Level  Files Size(MB) Score Time(sec)  Read(MB) Write(MB)    Rn(MB)  Rnp1(MB)  Wnew(MB) RW-Amplify Read(MB/s) Write(MB/s)      Rn     Rnp1     Wnp1     NewW    Count  Ln-stall Stall-cnt
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  0        7      464  46.4       281      3411      3875      3411         0      3875        2.1      12.1        13.8      621        0      240      240      628       0.0         0
Uptime(secs): 310.8 total, 2.0 interval
Writes cumulative: 9999999 total, 9999999 batches, 1.0 per batch, 1.22 ingest GB
WAL cumulative: 9999999 WAL writes, 9999999 WAL syncs, 1.00 writes per sync, 1.22 GB written
Compaction IO cumulative (GB): 1.22 new, 3.33 read, 3.78 write, 7.12 read+write
Compaction IO cumulative (MB/sec): 4.0 new, 11.0 read, 12.5 write, 23.4 read+write
Amplification cumulative: 4.1 write, 6.8 compaction
Writes interval: 100000 total, 100000 batches, 1.0 per batch, 12.5 ingest MB
WAL interval: 100000 WAL writes, 100000 WAL syncs, 1.00 writes per sync, 0.01 MB written
Compaction IO interval (MB): 12.49 new, 14.98 read, 21.50 write, 36.48 read+write
Compaction IO interval (MB/sec): 6.4 new, 7.6 read, 11.0 write, 18.6 read+write
Amplification interval: 101.7 write, 102.9 compaction
Stalls(secs): 142.924 level0_slowdown, 0.000 level0_numfiles, 0.805 memtable_compaction, 0.000 leveln_slowdown
Stalls(count): 132461 level0_slowdown, 0 level0_numfiles, 3 memtable_compaction, 0 leveln_slowdown

Task ID: #3329644, #3301695

Blame Rev:

Test Plan:
Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14583
2013-12-12 13:27:43 -08:00
kailiu
551e9428ce Merge branch 'master' into performance 2013-12-06 14:15:42 -08:00
Mark Callaghan
97aa401e2f Add compression options to db_bench
Summary:
This adds 2 options for compression to db_bench:
* universal_compression_size_percent
* compression_level - to set zlib compression level
It also logs compression_size_percent at startup in LOG

Task ID: #

Blame Rev:

Test Plan:
make check, run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14439
2013-12-03 14:28:48 -08:00