Commit Graph

320 Commits

Author SHA1 Message Date
Dhruba Borthakur
fbb73a4ac3 Support to disable background compactions on a database.
Summary:
This option is needed for fast bulk uploads. The goal is to load
all the data into files in L0 without any interference from
background compactions.

Test Plan: make clean check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6849
2012-11-20 21:12:06 -08:00
Dhruba Borthakur
3754f2f4ff A major bug that was not considering the compaction score of the n-1 level.
Summary:
The method Finalize() recomputes the compaction score of each
level and then sorts these score from largest to smallest. The
idea is that the level with the largest compaction score will
be a better candidate for compaction.  There are usually very
few levels, and a bubble sort code was used to sort these
compaction scores. There existed a bug in the sorting code that
skipped looking at the score for the n-1 level. This meant that
even if the compaction score of the n-1 level is large, it will
not be picked for compaction.

This patch fixes the bug and also introduces "asserts" in the
code to detect any possible inconsistencies caused by future bugs.

This bug existed in the very first code change that introduced
multi-threaded compaction to the leveldb code. That version of
code was committed on Oct 19th via
1ca0584345

Test Plan: make clean check OPT=-g

Reviewers: emayanke, sheki, MarkCallaghan

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6837
2012-11-20 15:44:21 -08:00
Dhruba Borthakur
dde70898a1 Fix asserts
Summary:
make check OPT=-g fails with the following assert.
==== Test DBTest.ApproximateSizes
db_test: db/version_set.cc:765: void leveldb::VersionSet::Builder::CheckConsistencyForDeletes(leveldb::VersionEdit*, int, int): Assertion `found' failed.

The assertion was that file #7 that was being deleted did not
preexists, but actualy it did pre-exist as shown in the manifest
dump shows below. The bug was that we did not check for file
existance at the same level.

*************************Edit[0] = VersionEdit {
  Comparator: leveldb.BytewiseComparator
}

*************************Edit[1] = VersionEdit {
  LogNumber: 8
  PrevLogNumber: 0
  NextFile: 9
  LastSeq: 80
  AddFile: 0 7 8005319 'key000000' @ 1 : 1 .. 'key000079' @ 80 : 1
}

*************************Edit[2] = VersionEdit {
  LogNumber: 8
  PrevLogNumber: 0
  NextFile: 13
  LastSeq: 80
  CompactPointer: 0 'key000079' @ 80 : 1
  DeleteFile: 0 7
  AddFile: 1 9 2101425 'key000000' @ 1 : 1 .. 'key000020' @ 21 : 1
  AddFile: 1 10 2101425 'key000021' @ 22 : 1 .. 'key000041' @ 42 : 1
  AddFile: 1 11 2101425 'key000042' @ 43 : 1 .. 'key000062' @ 63 : 1
  AddFile: 1 12 1701165 'key000063' @ 64 : 1 .. 'key000079' @ 80 : 1
}

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-19 14:51:22 -08:00
Dhruba Borthakur
a4b79b6e28 Merge branch 'master' into performance 2012-11-19 13:20:25 -08:00
Dhruba Borthakur
74054fa993 Fix compilation error while compiling unit tests with OPT=-g
Summary:
Fix compilation error while compiling with OPT=-g

Test Plan:
make clean check OPT=-g

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-19 13:16:46 -08:00
Dhruba Borthakur
48dafb2c59 Fix compilation error introduced by previous commit
7889e09455

Summary:
Fix compilation error introduced by previous commit
7889e09455

Test Plan:
make clean check
2012-11-19 12:16:45 -08:00
Dhruba Borthakur
7889e09455 Enhance manifest_dump to print each individual edit.
Summary:
The manifest file contains a series of edits. If the verbose
option is switched on, then print each individual edit in the
manifest file. This helps in debugging.

Test Plan: make clean manifest_dump

Reviewers: emayanke, sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6807
2012-11-19 12:04:35 -08:00
Abhishek Kona
661dc15721 Fix LDB dumpwal to print the messages as in the file.
Summary:
StringStream.clear() does not clear the stream. It sets some flags.
Who knew? Fixing that is not printing the stuff again and again.

Test Plan: ran it on a local db

Reviewers: dhruba, emayanke

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6795
2012-11-19 12:04:35 -08:00
amayank
65b035a47f Fix a coding error in db_test.cc
Summary: The new function MinLevelToCompress in db_test.cc was incomplete. It needs to tell the calling function-TEST whether the test has to be skipped or not

Test Plan: make all;./db_test

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: sheki

Differential Revision: https://reviews.facebook.net/D6771
2012-11-19 12:04:35 -08:00
Abhishek Kona
30742e1692 LDB can read WAL.
Summary:
Add option to read WAL and print a summary for each record.
facebook task => #1885013

E.G. Output :
./ldb dump_wal --walfile=/tmp/leveldbtest-5907/dbbench/026122.log --header
Sequence,Count,ByteSize
49981,1,100033
49981,1,100033
49982,1,100033
49981,1,100033
49982,1,100033
49983,1,100033
49981,1,100033
49982,1,100033
49983,1,100033
49984,1,100033
49981,1,100033
49982,1,100033

Test Plan:
Works run
./ldb read_wal --wal-file=/tmp/leveldbtest-5907/dbbench/000078.log --header

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: emayanke, leveldb, zshao

Differential Revision: https://reviews.facebook.net/D6675
2012-11-19 12:04:34 -08:00
Dhruba Borthakur
4b622ab0f2 Enhance manifest_dump to print each individual edit.
Summary:
The manifest file contains a series of edits. If the verbose
option is switched on, then print each individual edit in the
manifest file. This helps in debugging.

Test Plan: make clean manifest_dump

Reviewers: emayanke, sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6807
2012-11-19 12:02:27 -08:00
Abhishek Kona
b648401adb Fix LDB dumpwal to print the messages as in the file.
Summary:
StringStream.clear() does not clear the stream. It sets some flags.
Who knew? Fixing that is not printing the stuff again and again.

Test Plan: ran it on a local db

Reviewers: dhruba, emayanke

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6795
2012-11-19 11:14:07 -08:00
Dhruba Borthakur
62e7583f94 enhance dbstress to simulate hard crash
Summary:
dbstress has an option to reopen the database. Make it such that the
previous handle is not closed before we reopen, this simulates a
situation similar to a process crash.

Added new api to DMImpl to remove the lock file.

Test Plan: run db_stress

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6777
2012-11-18 23:16:17 -08:00
amayank
de278a6de9 Fix a coding error in db_test.cc
Summary: The new function MinLevelToCompress in db_test.cc was incomplete. It needs to tell the calling function-TEST whether the test has to be skipped or not

Test Plan: make all;./db_test

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: sheki

Differential Revision: https://reviews.facebook.net/D6771
2012-11-16 14:56:50 -08:00
Abhishek Kona
f5cdf931a0 LDB can read WAL.
Summary:
Add option to read WAL and print a summary for each record.
facebook task => #1885013

E.G. Output :
./ldb dump_wal --walfile=/tmp/leveldbtest-5907/dbbench/026122.log --header
Sequence,Count,ByteSize
49981,1,100033
49981,1,100033
49982,1,100033
49981,1,100033
49982,1,100033
49983,1,100033
49981,1,100033
49982,1,100033
49983,1,100033
49984,1,100033
49981,1,100033
49982,1,100033

Test Plan:
Works run
./ldb read_wal --wal-file=/tmp/leveldbtest-5907/dbbench/000078.log --header

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: emayanke, leveldb, zshao

Differential Revision: https://reviews.facebook.net/D6675
2012-11-16 09:09:00 -08:00
Dhruba Borthakur
c3392c9fe0 The db_stress test should also test multi-threaded compaction.
Summary:
Create more than one background compaction thread if specified.
This code peice is similar to what exists in db_bench.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D6753
2012-11-14 22:01:39 -08:00
Dhruba Borthakur
6c5a4d646a Merge branch 'master' into performance
Conflicts:
	db/db_impl.h
2012-11-14 21:39:52 -08:00
Dhruba Borthakur
e988c11f58 Enhance db_bench to be able to specify a grandparent_overlap_factor.
Summary:
The value specified in max_grandparent_overlap_factor is used to
limit the file size in a compaction run. This patch makes it
configurable when using db_bench.

Test Plan: make clean db_bench

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6729
2012-11-14 16:20:13 -08:00
Dhruba Borthakur
0f590af623 Push release 1.5.5.fb.
Summary:

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-13 16:28:11 -08:00
Dhruba Borthakur
33cf6f3bdc Make sse compilation optional.
Summary:
The fbcode compilation was always switching on msse by default.
This patch keeps the same behaviour but allows the compilation
process to switch off msse if needed.

If one does not want to use sse, then do the following:
export USE_SSE=0
make clean all

Test Plan: make clean all

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6717
2012-11-13 16:25:57 -08:00
Dhruba Borthakur
5d16e503a6 Improved CompactionFilter api: pass in a opaque argument to CompactionFilter invocation.
Summary:
There are applications that operate on multiple leveldb instances.
These applications will like to pass in an opaque type for each
leveldb instance and this type should be passed back to the application
with every invocation of the CompactionFilter api.

Test Plan: Enehanced unit test for opaque parameter to CompactionFilter.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, sheki, emayanke

Differential Revision: https://reviews.facebook.net/D6711
2012-11-13 16:22:26 -08:00
Dhruba Borthakur
43d9a8225a Fix asserts so that "make check OPT=-g" works on performance branch
Summary:
Compilation used to fail with the error:
db/version_set.cc:1773: error: ‘number_of_files_to_sort_’ is not a member of ‘leveldb::VersionSet’

I created a new method called CheckConsistencyForDeletes() so that
all the high cost checking is done only when OPT=-g is specified.

I also fixed a bug in PickCompactionBySize that was triggered when
OPT=-g was switched on. The base_index in the compaction record
was not set correctly.

Test Plan: make check OPT=-g

Differential Revision: https://reviews.facebook.net/D6687
2012-11-13 10:40:52 -08:00
Dhruba Borthakur
a785e029f7 The db_bench utility was broken in 1.5.4.fb because of a signed-unsigned comparision.
Summary:
The db_bench utility was broken in 1.5.4.fb because of a
signed-unsigned comparision.

The static variable FLAGS_min_level_to_compress was recently
changed from int to 'unsigned in' but it is initilized to a
nagative value -1.

The segfault is of this type:
Program received signal SIGSEGV, Segmentation fault.
Open (this=0x7fffffffdee0) at db/db_bench.cc:939
939	db/db_bench.cc: No such file or directory.
(gdb) where

Test Plan: run db_bench with no options.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6663
2012-11-12 13:59:35 -08:00
amayank
e626261742 Introducing "database reopens" into the stress test. Database will reopen after a specified number of iterations (configurable) of each thread when they will wait for the databse to reopen.
Summary: FLAGS_reopen (configurable) specifies the number of times the databse is to be reopened. FLAGS_ops_per_thread is divided into points based on that reopen field. At these points all threads come together to wait for the databse to reopen. Each thread "votes" for the database to reopen and when all have voted, the database reopens.

Test Plan: make all;./db_stress

Reviewers: dhruba, MarkCallaghan, sheki, asad, heyongqiang

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6627
2012-11-12 12:26:32 -08:00
heyongqiang
c64796fd34 Fix test failure of reduce_num_levels
Summary:
I changed the reduce_num_levels logic to avoid "compactRange()" call if the current number of levels in use (levels that contain files) is smaller than the new num of levels.
And that change breaks the assert in reduce_levels_test

Test Plan: run reduce_levels_test

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

CC: emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6651
2012-11-12 12:05:38 -08:00
Dhruba Borthakur
9c6c232e47 Compilation error while compiling with OPT=-g
Summary:
make clean check OPT=-g fails
leveldb::DBStatistics::getTickerCount(leveldb::Tickers)’:
./db/db_statistics.h:34: error: ‘MAX_NO_TICKERS’ was not declared in this scope
util/ldb_cmd.cc:255: warning: left shift count >= width of type

Test Plan:
make clean check OPT=-g

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-11 00:20:40 -08:00
Abhishek Kona
0f8e4721a5 Metrics: record compaction drop's and bloom filter effectiveness
Summary: Record BloomFliter hits and drop off reasons during compaction.

Test Plan: Unit tests work.

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6591
2012-11-09 11:38:45 -08:00
heyongqiang
20d18a89a3 disable size compaction in ldb reduce_levels and added compression and file size parameter to it
Summary:
disable size compaction in ldb reduce_levels, this will avoid compactions rather than the manual comapction,

added --compression=none|snappy|zlib|bzip2 and --file_size= per-file size to ldb reduce_levels command

Test Plan: run ldb

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

CC: sheki, emayanke

Differential Revision: https://reviews.facebook.net/D6597
2012-11-09 10:14:47 -08:00
Dhruba Borthakur
e00c709661 Preparing for new release 1.5.4.fb
Summary:
Preparing for new release 1.5.4.fb

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-09 09:21:11 -08:00
amayank
9e97bfdcde Introducing deletes for stress test
Summary: Stress test modified to do deletes and later verify them

Test Plan: running the test: db_stress

Reviewers: dhruba, heyongqiang, asad, sheki, MarkCallaghan

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6567
2012-11-08 16:55:18 -08:00
Abhishek Kona
391885c4e4 stat's collection in leveldb
Summary:
Prototype stat's collection. Diff is a good estimate of what
the final code will look like.
A few assumptions :
  * Used a global static instance of the statistics object. Plan to pass
  it to each internal function. Static allows metrics only at app
  level.
  * In the Ticker's do not do any locking. Depend on the mutex at each
   function of LevelDB. If we ever remove the mutex, we should change
   here too. The other option is use atomic objects anyways as there
   won't be any contention as they will be always acquired only by one
   thread.
  * The counters are dumb, increment through lifecycle. Plan to use ods
    etc to get last5min stat etc.

Test Plan:
made changes in db_bench
Ran ./db_bench --statistics=1 --num=10000 --cache_size=5000
This will print the cache hit/miss stats.

Reviewers: dhruba, heyongqiang

Differential Revision: https://reviews.facebook.net/D6441
2012-11-08 13:55:49 -08:00
Dhruba Borthakur
95dda37858 Move filesize-based-sorting to outside the Mutex
Summary:
When a new version is created, we sort all the files at every
level based on their size. This is necessary because we want
to compact the largest file first. The sorting takes quite a
bit of CPU.

Moved the sorting code to be outside the mutex. Also, the
earlier code was sorting files at all levels but we do not
need to sort the highest-number level because those files
are never the cause of any compaction. To reduce sorting
costs, we sort only the first few files in each level
because it is likely that those are the only files in that
level that will be picked for compaction.

At steady state, I have seen that this patch increase
throughout from 1500 writes/sec to 1700 writes/sec at the
end of a 72 hour run. The cpu saving by not sorting the
last level was not distinctive in this test run because
there were only 100K files in the highest numbered level.
I expect the cpu saving to be significant when the number of
files is much higher.

This is mostly an early preview and not ready for rigorous review.

With this patch, the writs/sec is now bottlenecked not by the sorting code but by GetOverlappingInputs. I am working on a patch to optimize GetOverlappingInputs.

Test Plan: make check

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D6411
2012-11-07 15:39:44 -08:00
Dhruba Borthakur
18cb6004d2 Fixed compilation error in previous merge.
Summary:
Fixed compilation error in previous merge.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-07 15:24:47 -08:00
Dhruba Borthakur
8143062edd Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/version_set.cc
	util/options.cc
2012-11-07 15:11:37 -08:00
heyongqiang
3fcf533ed0 Add a readonly db
Summary: as subject

Test Plan: run db_bench readrandom

Reviewers: dhruba

Reviewed By: dhruba

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6495
2012-11-07 14:19:48 -08:00
Dhruba Borthakur
9b87a2bae8 Avoid doing a exhaustive search when looking for overlapping files.
Summary:
The Version::GetOverlappingInputs() is called multiple times in
the compaction code path. Eack invocation does a binary search
for overlapping files in the specified key range.
This patch remembers the offset of an overlapped file when
GetOverlappingInputs() is called the first time within
a compaction run. Suceeding calls to GetOverlappingInputs()
uses the remembered index to avoid the binary search.

I measured that 1000 iterations of GetOverlappingInputs
takes around 4500 microseconds without this patch. If I use
this patch with the hint on every invocation, then 1000
iterations take about 3900 microsecond.

Test Plan: make check OPT=-g

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6513
2012-11-07 11:47:17 -08:00
Abhishek Kona
4e413df3d0 Flush Data at object destruction if disableWal is used.
Summary:
Added a conditional flush in ~DBImpl to flush.
There is still a chance of writes not being persisted if there is a
crash (not a clean shutdown) before the DBImpl instance is destroyed.

Test Plan: modified db_test to meet the new expectations.

Reviewers: dhruba, heyongqiang

Differential Revision: https://reviews.facebook.net/D6519
2012-11-06 15:04:42 -08:00
Dhruba Borthakur
aa42c66814 Fix all warnings generated by -Wall option to the compiler.
Summary:
The default compilation process now uses "-Wall" to compile.
Fix all compilation error generated by gcc.

Test Plan: make all check

Reviewers: heyongqiang, emayanke, sheki

Reviewed By: heyongqiang

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6525
2012-11-06 14:07:31 -08:00
Dhruba Borthakur
5f91868cee Merge branch 'master' into performance
Conflicts:
	db/version_set.cc
	util/options.cc
2012-11-05 16:51:55 -08:00
Dhruba Borthakur
cb7a00227f The method GetOverlappingInputs should use binary search.
Summary:
The method Version::GetOverlappingInputs used a sequential search
to map a kay-range to a set of files. But the files are arranged
in ascending order of key, so a biary search is more effective.

This patch implements Version::GetOverlappingInputsBinarySearch
that finds one file that corresponds to the specified key range
and then iterates backwards and forwards to find all overlapping
files.

This patch is critical for making compactions efficient, especially
when there are thousands of files in a single level.

I measured that 1000 iterations of TEST_MaxNextLevelOverlappingBytes
takes 16000 microseconds without this patch. With this patch, the
same method takes about 4600 microseconds.

Test Plan: Almost all unit tests in db_test uses this method to lookup keys.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6465
2012-11-05 16:08:01 -08:00
Dhruba Borthakur
5273c81483 Ability to invoke application hook for every key during compaction.
Summary:
There are certain use-cases where the application intends to
delete older keys aftre they have expired a certian time period.
One option for those applications is to periodically scan the
entire database and delete appropriate keys.

A better way is to allow the application to hook into the
compaction process. This patch allows the application to set
a method callback for every key that is being compacted. If
this method returns true, then the key is not preserved in
the output of the compaction.

Test Plan:
This is mostly to preview the proposed new public api.
Since it is a public api, please do due diligence on reviewing it.

I will be writing test cases for this api in mynext version of
this patch.

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: heyongqiang

CC: sheki, adsharma

Differential Revision: https://reviews.facebook.net/D6285
2012-11-05 16:02:13 -08:00
heyongqiang
f1a7c735b5 fix complie error
Summary:

as subject

Test Plan:n/a
2012-11-05 10:30:19 -08:00
heyongqiang
d55c2ba305 Add a tool to change number of levels
Summary: as subject.

Test Plan: manually test it, will add a testcase

Reviewers: dhruba, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6345
2012-11-05 10:17:39 -08:00
Dhruba Borthakur
81f735d97c Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	util/options.cc
2012-11-05 09:41:38 -08:00
Dhruba Borthakur
a1bd5b7752 Compilation problem introduced by previous
commit 854c66b089.

Summary:
Compilation problem introduced by previous
commit 854c66b089.

Test Plan:  make check
2012-11-04 22:04:14 -08:00
amayank
854c66b089 Make compression options configurable. These include window-bits, level and strategy for ZlibCompression
Summary: Leveldb currently uses windowBits=-14 while using zlib compression.(It was earlier 15). This makes the setting configurable. Related changes here: https://reviews.facebook.net/D6105

Test Plan: make all check

Reviewers: dhruba, MarkCallaghan, sheki, heyongqiang

Differential Revision: https://reviews.facebook.net/D6393
2012-11-02 11:26:39 -07:00
heyongqiang
3096fa7534 Add two more options: disable block cache and make table cache shard number configuable
Summary:

as subject

Test Plan:

run db_bench and db_test

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6111
2012-11-01 13:23:21 -07:00
Mark Callaghan
3e7e269292 Use timer to measure sleep rather than assume it is 1000 usecs
Summary:
This makes the stall timers in MakeRoomForWrite more accurate by timing
the sleeps. From looking at the logs the real sleep times are usually
about 2000 usecs each when SleepForMicros(1000) is called. The modified LOG messages are:
2012/10/29-12:06:33.271984 2b3cc872f700 delaying write 13 usecs for level0_slowdown_writes_trigger
2012/10/29-12:06:34.688939 2b3cc872f700 delaying write 1728 usecs for rate limits with max score 3.83

Task ID: #

Blame Rev:

Test Plan:
run db_bench, look at DB/LOG

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

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

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6297
2012-10-30 07:21:37 -07:00
heyongqiang
fb8d437325 fix test failure
Summary: as subject

Test Plan: db_test

Reviewers: dhruba, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6309
2012-10-29 18:55:52 -07:00
heyongqiang
925f60d39d add a test case to make sure chaning num_levels will fail Summary:
Summary: as subject

Test Plan: db_test

Reviewers: dhruba, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6303
2012-10-29 15:27:07 -07:00