Commit Graph

36 Commits

Author SHA1 Message Date
Islam AbdelRahman
869ae5d786 Support IngestExternalFile (remove AddFile restrictions)
Summary:
Changes in the diff

API changes:
- Introduce IngestExternalFile to replace AddFile (I think this make the API more clear)
- Introduce IngestExternalFileOptions (This struct will encapsulate the options for ingesting the external file)
- Deprecate AddFile() API

Logic changes:
- If our file overlap with the memtable we will flush the memtable
- We will find the first level in the LSM tree that our file key range overlap with the keys in it
- We will find the lowest level in the LSM tree above the the level we found in step 2 that our file can fit in and ingest our file in it
- We will assign a global sequence number to our new file
- Remove AddFile restrictions by using global sequence numbers

Other changes:
- Refactor all AddFile logic to be encapsulated in ExternalSstFileIngestionJob

Test Plan:
unit tests (still need to add more)
addfile_stress (https://reviews.facebook.net/D65037)

Reviewers: yiwu, andrewkr, lightmark, yhchiang, sdong

Reviewed By: sdong

Subscribers: jkedgar, hcz, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D65061
2016-10-20 17:05:32 -07:00
Islam AbdelRahman
b88f8e87c5 Support SST files with Global sequence numbers [reland]
Summary:
reland https://reviews.facebook.net/D62523

- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file

Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks

Test Plan: unit tests

Reviewers: sdong, yhchiang

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D65211
2016-10-18 16:59:37 -07:00
Islam AbdelRahman
d11c09d9e2 Eliminate memcpy from ForwardIterator
Summary:
This diff update ForwardIterator to support pinning keys and values, which will allow DBIter to take advantage of that and eliminate memcpy when executing merge operators
This diff is stacked on D61305

Test Plan:
existing tests (updated them to test tailing iterator)
new test

Reviewers: andrewkr, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60009
2016-08-11 19:10:16 -07:00
sdong
56dd034115 read_options.background_purge_on_iterator_cleanup to cover forward iterator and log file closing too.
Summary: With read_options.background_purge_on_iterator_cleanup=true, File deletion and closing can still happen in forward iterator, or WAL file closing. Cover those cases too.

Test Plan: I am adding unit tests.

Reviewers: andrewkr, IslamAbdelRahman, yiwu

Reviewed By: yiwu

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61503
2016-08-10 13:16:41 -07:00
Islam AbdelRahman
ccecf3f4fb UniversalCompaction should ignore sorted runs being compacted (when compacting for file num)
Summary:
If we have total number of sorted runs greater than level0_file_num_compaction_trigger, Universal compaction will always issue a compaction
even if the number of sorted runs that are not being compacted is less than level0_file_num_compaction_trigger.

This diff changes this behaviour to relay on the `number of sorted runs not being compacted` instead of `total number of sorted runs`

Test Plan: New unit test

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61533
2016-08-10 12:37:43 -07:00
Islam AbdelRahman
68a8e6b8fa Introduce FullMergeV2 (eliminate memcpy from merge operators)
Summary:
This diff update the code to pin the merge operator operands while the merge operation is done, so that we can eliminate the memcpy cost, to do that we need a new public API for FullMerge that replace the std::deque<std::string> with std::vector<Slice>

This diff is stacked on top of D56493 and D56511

In this diff we
- Update FullMergeV2 arguments to be encapsulated in MergeOperationInput and MergeOperationOutput which will make it easier to add new arguments in the future
- Replace std::deque<std::string> with std::vector<Slice> to pass operands
- Replace MergeContext std::deque with std::vector (based on a simple benchmark I ran https://gist.github.com/IslamAbdelRahman/78fc86c9ab9f52b1df791e58943fb187)
- Allow FullMergeV2 output to be an existing operand

```
[Everything in Memtable | 10K operands | 10 KB each | 1 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=10000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       0.607 micros/op 1648235 ops/sec; 16121.2 MB/s
readseq      :       0.478 micros/op 2091546 ops/sec; 20457.2 MB/s
readseq      :       0.252 micros/op 3972081 ops/sec; 38850.5 MB/s
readseq      :       0.237 micros/op 4218328 ops/sec; 41259.0 MB/s
readseq      :       0.247 micros/op 4043927 ops/sec; 39553.2 MB/s

[master]
readseq      :       3.935 micros/op 254140 ops/sec; 2485.7 MB/s
readseq      :       3.722 micros/op 268657 ops/sec; 2627.7 MB/s
readseq      :       3.149 micros/op 317605 ops/sec; 3106.5 MB/s
readseq      :       3.125 micros/op 320024 ops/sec; 3130.1 MB/s
readseq      :       4.075 micros/op 245374 ops/sec; 2400.0 MB/s
```

```
[Everything in Memtable | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=1000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       3.472 micros/op 288018 ops/sec; 2817.1 MB/s
readseq      :       2.304 micros/op 434027 ops/sec; 4245.2 MB/s
readseq      :       1.163 micros/op 859845 ops/sec; 8410.0 MB/s
readseq      :       1.192 micros/op 838926 ops/sec; 8205.4 MB/s
readseq      :       1.250 micros/op 800000 ops/sec; 7824.7 MB/s

[master]
readseq      :      24.025 micros/op 41623 ops/sec;  407.1 MB/s
readseq      :      18.489 micros/op 54086 ops/sec;  529.0 MB/s
readseq      :      18.693 micros/op 53495 ops/sec;  523.2 MB/s
readseq      :      23.621 micros/op 42335 ops/sec;  414.1 MB/s
readseq      :      18.775 micros/op 53262 ops/sec;  521.0 MB/s

```

```
[Everything in Block cache | 10K operands | 10 KB each | 1 operand per key]

[FullMergeV2]
$ DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions
readseq      :      14.741 micros/op 67837 ops/sec;  663.5 MB/s
readseq      :       1.029 micros/op 971446 ops/sec; 9501.6 MB/s
readseq      :       0.974 micros/op 1026229 ops/sec; 10037.4 MB/s
readseq      :       0.965 micros/op 1036080 ops/sec; 10133.8 MB/s
readseq      :       0.943 micros/op 1060657 ops/sec; 10374.2 MB/s

[master]
readseq      :      16.735 micros/op 59755 ops/sec;  584.5 MB/s
readseq      :       3.029 micros/op 330151 ops/sec; 3229.2 MB/s
readseq      :       3.136 micros/op 318883 ops/sec; 3119.0 MB/s
readseq      :       3.065 micros/op 326245 ops/sec; 3191.0 MB/s
readseq      :       3.014 micros/op 331813 ops/sec; 3245.4 MB/s
```

```
[Everything in Block cache | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10-operands-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions

[FullMergeV2]
readseq      :      24.325 micros/op 41109 ops/sec;  402.1 MB/s
readseq      :       1.470 micros/op 680272 ops/sec; 6653.7 MB/s
readseq      :       1.231 micros/op 812347 ops/sec; 7945.5 MB/s
readseq      :       1.091 micros/op 916590 ops/sec; 8965.1 MB/s
readseq      :       1.109 micros/op 901713 ops/sec; 8819.6 MB/s

[master]
readseq      :      27.257 micros/op 36687 ops/sec;  358.8 MB/s
readseq      :       4.443 micros/op 225073 ops/sec; 2201.4 MB/s
readseq      :       5.830 micros/op 171526 ops/sec; 1677.7 MB/s
readseq      :       4.173 micros/op 239635 ops/sec; 2343.8 MB/s
readseq      :       4.150 micros/op 240963 ops/sec; 2356.8 MB/s
```

Test Plan: COMPILE_WITH_ASAN=1 make check -j64

Reviewers: yhchiang, andrewkr, sdong

Reviewed By: sdong

Subscribers: lovro, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57075
2016-07-20 09:49:03 -07:00
Aaron Gao
dda6c72ac8 Add DestroyColumnFamilyHandle(ColumnFamilyHandle**) to db.h
Summary:
add DestroyColumnFamilyHandle(ColumnFamilyHandle**) to close column family instead of deleting cfh*
User should call this to close a cf and then we can detect the deletion in this function.

Test Plan: make all check -j64

Reviewers: andrewkr, yiwu, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60765
2016-07-13 17:59:25 -07:00
Aaron Gao
8e6b38d895 update DB::AddFile to ingest list of sst files
Summary:
DB::AddFile(std::string file_path) API that allow them to ingest an SST file created using SstFileWriter
We want to update this interface to be able to accept a list of files that will be ingested, DB::AddFile(std::vector<std::string> file_path_list).

Test Plan:
Add test case `AddExternalSstFileList` in `DBSSTTest`. To make sure:
1. files key ranges are not overlapping with each other
2. each file key range dont overlap with the DB key range
3. make sure no snapshots are held

Reviewers: andrewkr, sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58587
2016-07-11 10:43:12 -07:00
Islam AbdelRahman
fa813f7478 Update DB::AddFile() to ingest the file to the lowest possible level
Summary:
DB::AddFile() right now always add the ingested file to L0
update the logic to add the file to the lowest possible level

Test Plan: unit tests

Reviewers: jkedgar, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, yoshinorim

Differential Revision: https://reviews.facebook.net/D59637
2016-06-21 17:57:59 -07:00
sdong
7b79238b65 Deprectate filter_deletes
Summary: filter_deltes is not a frequently used feature. Remove it.

Test Plan: Run all test suites.

Reviewers: igor, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59427
2016-06-17 10:30:47 -07:00
sdong
6a14f7a976 Change several option defaults
Summary:
Changing several option defaults:
 options.max_open_files changes from 5000 to -1
 options.base_background_compactions changes from max_background_compactions to 1
 options.wal_recovery_mode changes from kTolerateCorruptedTailRecords to kTolerateCorruptedTailRecords
 options.compaction_pri changes from kByCompensatedSize to kByCompensatedSize

Test Plan: Write unit tests to see OldDefaults() works as expected.

Reviewers: IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: MarkCallaghan, yiwu, kradhakrishnan, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56427
2016-04-28 17:50:58 -07:00
Andrew Kryczka
73a847ef89 Add per-level compression ratio property
Summary:
This is needed so we can measure compression ratio improvements
achieved by D52287.

The property compares raw data size against the total file size for a given
level. If the level is empty it should return 0.0.

Test Plan: new unit test

Reviewers: IslamAbdelRahman, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D56967
2016-04-20 18:46:54 -07:00
Yi Wu
792762c42c Split db_test.cc
Summary: Split db_test.cc into several files. Moving several helper functions into DBTestBase.

Test Plan: make check

Reviewers: sdong, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: dhruba, andrewkr, kradhakrishnan, yhchiang, leveldb, sdong

Differential Revision: https://reviews.facebook.net/D56715
2016-04-18 09:42:50 -07:00
sdong
4b6833aec1 Rename options.compaction_measure_io_stats to options.report_bg_io_stats and include flush too.
Summary: It is useful to print out IO stats in flush jobs too. Extend options.compaction_measure_io_stats to flush jobs and raname it.

Test Plan: Try db_bench and see the stats are printed out.

Reviewers: yhchiang

Reviewed By: yhchiang

Subscribers: kradhakrishnan, yiwu, IslamAbdelRahman, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56769
2016-04-15 10:22:18 -07:00
sdong
2feafa3db9 Change some RocksDB default options
Summary: Change some RocksDB default options to make it more friendly to server workloads.

Test Plan: Run all existing tests

Reviewers: yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: sumeet, muthu, benj, MarkCallaghan, igor, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D55941
2016-03-31 17:12:18 -07:00
Islam AbdelRahman
df9ba6df62 Introduce SstFileManager::SetMaxAllowedSpaceUsage() to cap disk space usage
Summary:
Introude SstFileManager::SetMaxAllowedSpaceUsage() that can be used to limit the maximum space usage allowed for RocksDB.
When this limit is exceeded WriteImpl() will fail and return Status::Aborted()

Test Plan: unit testing

Reviewers: yhchiang, anthony, andrewkr, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D53763
2016-02-17 15:20:23 -08:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Islam AbdelRahman
8e6172bc57 Add BlockBasedTableOptions::index_block_restart_interval
Summary: Add a new option to BlockBasedTableOptions that will allow us to change the restart interval for the index block

Test Plan: unit tests

Reviewers: yhchiang, anthony, andrewkr, sdong

Reviewed By: sdong

Subscribers: march, dhruba

Differential Revision: https://reviews.facebook.net/D53721
2016-02-05 10:22:37 -08:00
Nathan Bronson
9c2cf9479b Fix for --allow_concurrent_memtable_write with batching
Summary:
Concurrent memtable adds were incorrectly computing
the last sequence number for a write batch group when the
write batches were not solitary.  This is the cause of
https://github.com/facebook/mysql-5.6/issues/155

Test Plan:
1. unit tests
2. new unit test
3. parallel db_bench stress tests with batch size of 10 and asserts enabled

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: IslamAbdelRahman, MarkCallaghan, dhruba

Differential Revision: https://reviews.facebook.net/D53595
2016-02-01 20:41:57 -08:00
Islam AbdelRahman
d6c838f1e1 Add SstFileManager (component tracking all SST file in DBs and control the deletion rate)
Summary:
Add a new class SstFileTracker that will be notified whenever a DB add/delete/move and sst file, it will also replace DeleteScheduler
SstFileTracker can be used later to abort writes when we exceed a specific size

Test Plan: unit tests

Reviewers: rven, anthony, yhchiang, sdong

Reviewed By: sdong

Subscribers: igor, lovro, march, dhruba

Differential Revision: https://reviews.facebook.net/D50469
2016-01-28 18:35:01 -08:00
sdong
da33dfe188 Parameterize DBTest.Randomized
Summary: Break down DBTest.Randomized to multiple gtest tests based on config type

Test Plan: Run the test and all tests. Make sure configurations are correctly set

Reviewers: yhchiang, IslamAbdelRahman, rven, kradhakrishnan, andrewkr, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53247
2016-01-25 14:49:08 -08:00
Siying Dong
fa3dbf203f Merge pull request #853 from Vaisman/enable_C4267_warning
Enable C4267 warning
2015-12-08 17:59:24 -08:00
krad
d3bb572da6 Build break fix.
Summary: Skip list now cannot estimate memory across allocators
consistently and hence triggers flush at different time. This breaks certain
unit tests.

The fix is to adopt key count instead of size for flush.

Test Plan: Ran test on dev box and mac (where it used to fail)

Reviewers: sdong

CC: leveldb@

Task ID: #9273334

Blame Rev:
2015-12-04 11:45:51 -08:00
sdong
ef8ed3681c Fix DBTest.SuggestCompactRangeTest for disable jemalloc case
Summary: DBTest.SuggestCompactRangeTest fails for the case when jemalloc is disabled, including ASAN and valgrind builds. It is caused by the improvement of skip list, which allocates different size of nodes for a new records. Fix it by using a special mem table that triggers a flush by number of entries. In that way the behavior will be consistent for all allocators.

Test Plan: Run the test with both of DISABLE_JEMALLOC=1 and 0

Reviewers: anthony, rven, yhchiang, kradhakrishnan, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51423
2015-11-30 16:40:47 -08:00
Vasili Svirski
41b32c6059 Enable C4267 warning
* conversion from 'size_t' to 'type', by add static_cast

Tested:
* by build solution on Windows, Linux locally,
* run tests
* build CI system successful
2015-11-24 16:33:09 +03:00
sdong
189b3e03df Fix uninitilizeded SpecialEnv::time_elapse_only_sleep_
Summary: SpecialEnv::time_elapse_only_sleep_ is not initialized, which might cause some test failures. Fix it.

Test Plan: Run some unit tests. Since tests already broken. Might want to commit it sooner.

Reviewers: IslamAbdelRahman, yhchiang, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D50937
2015-11-17 16:22:17 -08:00
Yueh-Hsuan Chiang
e114f0abb8 Enable RocksDB to persist Options file.
Summary:
This patch allows rocksdb to persist options into a file on
DB::Open, SetOptions, and Create / Drop ColumnFamily.
Options files are created under the same directory as the rocksdb
instance.

In addition, this patch also adds a fail_if_missing_options_file in DBOptions
that makes any function call return non-ok status when it is not able to
persist options properly.

  // If true, then DB::Open / CreateColumnFamily / DropColumnFamily
  // / SetOptions will fail if options file is not detected or properly
  // persisted.
  //
  // DEFAULT: false
  bool fail_if_missing_options_file;

Options file names are formatted as OPTIONS-<number>, and RocksDB
will always keep the latest two options files.

Test Plan:
Add options_file_test.

options_test
column_family_test

Reviewers: igor, IslamAbdelRahman, sdong, anthony

Reviewed By: anthony

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48285
2015-11-10 22:58:01 -08:00
Nathan Bronson
b81b430987 Switch to thread-local random for skiplist
Summary:
Using a TLS random instance for skiplist makes it smaller
(useful for hash_skiplist_rep) and prepares skiplist for concurrent
adds.  This diff also modifies the branching factor math to avoid an
unnecessary division.

This diff has the effect of changing the sequence of skip list node
height choices made by tests, so it has the potential to cause unit
test failures for tests that implicitly rely on the exact structure
of the skip list.  Tests that try to exactly trigger a compaction are
likely suspects for this problem (these tests have always been brittle to
changes in the skiplist details).  I've minimizes this risk by reseeding
the main thread's Random at the beginning of each test, increasing the
universal compaction size_ratio limit from 101% to 105% for some tests,
and verifying that the tests pass many times.

Test Plan: for i in `seq 0 9`; do make check; done

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D50439
2015-11-09 19:25:22 -08:00
Siying Dong
138876a62c Merge pull request #746 from ceph/wip-recycle
Add Options.recycle_log_file_num for Recycling WAL Files
2015-10-26 15:01:28 -07:00
Dmitri Smirnov
3c750b59ae No need to #ifdef test only code on windows 2015-10-22 15:15:37 -07:00
Sage Weil
7188052107 db_test_util: add recycle_log_files to set of tested options
Signed-off-by: Sage Weil <sage@redhat.com>
2015-10-18 21:24:32 -04:00
Islam AbdelRahman
952ad994a9 Fix db_test under ROCKSDB_LITE
Summary:
This diff exclude alot of tests in db_test that are not compiling / failing under ROCKSD_LITE

Test Plan:
OPT=-DROCKSDB_LITE make check -j64
make check -j64

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48771
2015-10-15 10:59:31 -07:00
Islam AbdelRahman
f55d3009c0 Make db_test_util compile under ROCKSDB_LITE
Summary: db_test_util is used in multiple test files but it dont compile under ROCKSDB_LITE

Test Plan:
make check
make static_lib
OPT=-DROCKSDB_LITE make db_wal_test

Reviewers: igor, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48579
2015-10-13 17:33:23 -07:00
sdong
35ad531be3 Seperate InternalIterator from Iterator
Summary:
Separate a new class InternalIterator from class Iterator, when the look-up is done internally, which also means they operate on key with sequence ID and type.

This change will enable potential future optimizations but for now InternalIterator's functions are still the same as Iterator's.
At the same time, separate the cleanup function to a separate class and let both of InternalIterator and Iterator inherit from it.

Test Plan: Run all existing tests.

Reviewers: igor, yhchiang, anthony, kradhakrishnan, IslamAbdelRahman, rven

Reviewed By: rven

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48549
2015-10-13 15:32:13 -07:00
Islam AbdelRahman
c64ae05b1c Move TEST_NewInternalIterator to NewInternalIterator
Summary:
Long time ago we add InternalDumpCommand to ldb_tool https://reviews.facebook.net/D11517
This command is using TEST_NewInternalIterator although it's not a test. This patch move TEST_NewInternalIterator outside of db_impl_debug.cc

Test Plan:
make check
make static_lib

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48561
2015-10-12 17:22:37 -07:00
Venkatesh Radhakrishnan
f1fdf5205b Clean up dependency: Move db_test_util.* to db directory
Summary:
As part of tech debt week, we are cleaning up dependencies.
This diff moves db_test_util.[h,cc] from util to db directory.

Test Plan: make check

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D48543
2015-10-12 13:05:42 -07:00