Commit Graph

285 Commits

Author SHA1 Message Date
Yueh-Hsuan Chiang
be8621ffaf Fix compile warning in compact_on_deletion_collector in some environment
Summary: Fix compile warning in compact_on_deletion_collector some environment

Test Plan: make

Reviewers: igor, sdong, anthony, IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43467
2015-08-03 20:53:15 -07:00
Yueh-Hsuan Chiang
26894303c1 Add CompactOnDeletionCollector in utilities/table_properties_collectors.
Summary:
This diff adds CompactOnDeletionCollector in utilities/table_properties_collectors,
which applies a sliding window to a sst file and mark this file as need-compaction
when it observe enough deletion entries within the consecutive keys covered by
the sliding window.

Test Plan: compact_on_deletion_collector_test

Reviewers: igor, anthony, IslamAbdelRahman, kradhakrishnan, yoshinorim, sdong

Reviewed By: sdong

Subscribers: maykov, dhruba

Differential Revision: https://reviews.facebook.net/D41175
2015-08-03 20:42:55 -07:00
agiardullo
8161bdb5a0 WriteBatch Save Points
Summary:
Support RollbackToSavePoint() in WriteBatch and WriteBatchWithIndex.  Support for partial transaction rollback is needed for MyRocks.

An alternate implementation of Transaction::RollbackToSavePoint() exists in D40869.  However, the other implementation is messier because it is implemented outside of WriteBatch.  This implementation is much cleaner and also exposes a potentially useful feature to WriteBatch.

Test Plan: Added unit tests

Reviewers: IslamAbdelRahman, kradhakrishnan, maykov, yoshinorim, hermanlee4, spetrunia, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42723
2015-07-29 16:54:23 -07:00
sdong
85ac65536b Tests to avoid to use TMPDIR directly
Summary: Directly using TMPDIR can cause problems when running tests using parallel option. Fix them.

Test Plan: Run all tests in parallel

Reviewers: kradhakrishnan, yhchiang, IslamAbdelRahman, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D42807
2015-07-21 19:07:34 -07:00
agiardullo
064294081b Improved FileExists API
Summary: Add new CheckFileExists method.  Considered changing the FileExists api but didn't want to break anyone's builds.

Test Plan: unit tests

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42003
2015-07-20 17:20:40 -07:00
Islam AbdelRahman
aa8ac6445b Skip unsupported tests in ROCKSDB_LITE
Summary:
Skipping these tests in ROCKSDB_LITE since they are not supported
json_document_test
wal_manager_test
ttl_test
sst_dump_test
deletefile_test
compact_files_test
prefix_test
checkpoint_test

Test Plan:
json_document_test
wal_manager_test
ttl_test
sst_dump_test
deletefile_test
compact_files_test
prefix_test
checkpoint_test

Reviewers: igor, sdong, yhchiang, kradhakrishnan, anthony

Reviewed By: anthony

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D42573
2015-07-20 11:24:54 -07:00
Islam AbdelRahman
144d2910db Block backupable_db_test_lite in ROCKSDB_LITE
Summary: BackupableDB is not supported in ROCKSDB_LITE, blocking backupable_db_test_lite

Test Plan: backupable_db_test

Reviewers: sdong, igor, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D42165
2015-07-20 11:15:16 -07:00
sdong
6e9fbeb27c Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.

Test Plan: Run all existing unit tests.

Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D42321
2015-07-17 16:58:18 -07:00
Islam AbdelRahman
26ca893198 Block document_db_test in ROCKSDB_LITE
Summary: DocumentDB is not supported in ROCKSDB_LITE

Test Plan: document_db_test

Reviewers: yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D42177
2015-07-17 12:54:30 -07:00
Igor Canadi
35ca59364c Don't let flushes preempt compactions
Summary:
When we first started, max_background_flushes was 0 by default and compaction thread was executing flushes (since there was no flush thread). Then, we switched the default max_background_flushes to 1. However, we still support the case where there is no flush thread and flushes are done in compaction. This is making our code a bit more complicated. By not supporting this use-case we can make our code simpler.

We have a special case that when you set max_background_flushes to 0, we
schedule the flush to execute on the compaction thread.

Test Plan: make check (there might be some unit tests that depend on this behavior)

Reviewers: IslamAbdelRahman, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D41931
2015-07-17 12:02:52 -07:00
Andres Notzli
1d20fa9d0f Fixed and simplified merge_helper
Summary:
MergeUntil was not reporting a success when merging an operand with
a Value/Deletion despite the comments in MergeHelper and CompactionJob
indicating otherwise. This lead to operands being written to the compaction
output unnecessarily:

M1 M2 M3 P M4 M5 --> (P+M1+M2+M3) M2 M3 M4 M5 (before the diff)
M1 M2 M3 P M4 M5 --> (P+M1+M2+M3) M4 M5 (after the diff)

In addition, the code handling Values/Deletion was basically identical.
This patch unifies the code. Finally, this patch also adds testing for
merge_helper.

Test Plan: make && make check

Reviewers: sdong, rven, yhchiang, tnovak, igor

Reviewed By: igor

Subscribers: tnovak, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42351
2015-07-17 09:27:24 -07:00
Dmitri Smirnov
d1a457181d Ensure Windows build w/o port/port.h in public headers
- Remove make file defines from public headers and use _WIN32 because it is compiler defined
 - use __GNUC__ and __clang__ to guard non-portable attributes
 - add #include "port/port.h" to some new .cc files.
 - minor changes in CMakeLists to reflect recent changes
2015-07-16 12:10:16 -07:00
agiardullo
81d072623c move convenience.h out of utilities
Summary: Moved convenience.h out of utilities to remove a dependency on utilities in db.

Test Plan: unit tests.  Also compiled a link to the old location to verify the _Pragma works.

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42201
2015-07-15 14:51:51 -07:00
Igor Canadi
8a9fca2619 Better error handling in BackupEngine
Summary:
Couple of changes here:
* NewBackupEngine() and NewReadOnlyBackupEngine() are now removed. They were deprecated since RocksDB 3.8. Changing these to new functions should be pretty straight-forward. As a followup, I'll fix all fbcode callsights
* Instead of initializing backup engine in the constructor, we initialize it in a separate function now. That way, we can catch all errors and return appropriate status code.
* We catch all errors during initializations and return them to the client properly.
* Added new tests to backupable_db_test, to make sure that we can't open BackupEngine when there are Env errors.
* Transitioned backupable_db_test to use BackupEngine rather than BackupableDB. From the two available APIs, judging by the current use-cases, it looks like BackupEngine API won. It's much more flexible since it doesn't require StackableDB.

Test Plan: Added a new unit test to backupable_db_test

Reviewers: yhchiang, sdong, AaronFeldman

Reviewed By: AaronFeldman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D41925
2015-07-14 20:51:36 +02:00
agiardullo
18d5e1bf88 Remove db_impl_readonly dependency on utilities
Summary: Seems like the cleanest way to resolve this is to move CompactedDBImpl into db/.  CompactedDBImpl should probably live in the same place as DBImplReadonly since Opening the latter could end up instantiating the former.  Both DBImplReadonly and CompactedDBImpl inherit from DBImpl access protected members of DBImpl( and the latter access friendly private methods).

Test Plan: unit tests

Reviewers: sdong, yhchiang, kradhakrishnan, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42027
2015-07-14 11:32:54 -07:00
Islam AbdelRahman
04d201fa0b Block spatial_db_test in ROCKSDB_LITE
Summary: Block spatial_db_test in ROCKSDB_LITE as SpatialDB is not supported

Test Plan: spatial_db_test

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D41991
2015-07-13 18:35:03 -07:00
Islam AbdelRahman
e8e8c90499 fix compile for optimistic_transaction_test under ROCKSDB_LITE
Summary: Adding a main for optimistic_transaction_test that report that it was skipped when using ROCKSDB_LITE

Test Plan: optimistic_transaction_test

Reviewers: yhchiang, sdong, igor, anthony

Reviewed By: anthony

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D41979
2015-07-13 16:42:40 -07:00
sdong
f9728640f3 "make format" against last 10 commits
Summary: This helps Windows port to format their changes, as discussed. Might have formatted some other codes too becasue last 10 commits include more.

Test Plan: Build it.

Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D41961
2015-07-13 13:50:18 -07:00
Dmitri Smirnov
c903ccc4c2 Merge from github/master 2015-07-09 18:01:08 -07:00
Dmitri Smirnov
ef4b87f1b2 Commit both PR and internal code review changes 2015-07-07 16:58:20 -07:00
Aaron Feldman
e12b403991 Initialize threads later in constructor
Summary: This addresses a test failure where an exception occured in the constructor's call to CreateDirIfMissing(). The existence of unjoined threads prevented this exception from propogating properly. See http://stackoverflow.com/questions/7381757/c-terminate-called-without-an-active-exception

Test Plan: Re-run tests from task #7626266

Reviewers: sdong, anthony, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D41313
2015-07-07 10:49:16 -07:00
Dmitri Smirnov
d2f0912bd3 Merge the latest changes from github/master 2015-07-02 17:23:41 -07:00
Dmitri Smirnov
feb99c31a4 Merge remote-tracking branch 'origin' into ms_win_port 2015-07-02 13:14:18 -07:00
Aaron Feldman
e70115e71b Fix unity build by removing anonymous namespace
Summary: see title

Test Plan: run 'make unity'

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D41079
2015-07-02 12:27:35 -07:00
Aaron Feldman
a69bc91e37 Multithreaded backup and restore in BackupEngineImpl
Summary:
Add a new field: BackupableDBOptions.max_background_copies.
CreateNewBackup() and RestoreDBFromBackup() will use this number of threads to perform copies.
If there is a backup rate limit, then max_background_copies must be 1.
Update backupable_db_test.cc to test multi-threaded backup and restore.
Update backupable_db_test.cc to test backups when the backup environment is not the same as the database environment.

Test Plan:
Run ./backupable_db_test
Run valgrind ./backupable_db_test
Run with TSAN and ASAN

Reviewers: yhchiang, rven, anthony, sdong, igor

Reviewed By: igor

Subscribers: yhchiang, anthony, sdong, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D40725
2015-07-02 11:35:51 -07:00
Dmitri Smirnov
9dbde7277c Merge remote-tracking branch 'origin' into ms_win_port 2015-07-02 11:34:22 -07:00
Dmitri Smirnov
ca2fe2c1b6 Address GCC compilation issues
invalid suffix on literal
 no return statement in function returning non-void CuckooStep::operator=
 extra qualification ‘rocksdb::spatial::Variant::
 dereferencing type-punned pointer will break strict-aliasing rules
2015-07-01 17:04:08 -07:00
Dmitri Smirnov
18285c1e2f Windows Port from Microsoft
Summary: Make RocksDb build and run on Windows to be functionally
 complete and performant. All existing test cases run with no
 regressions. Performance numbers are in the pull-request.

 Test plan: make all of the existing unit tests pass, obtain perf numbers.

 Co-authored-by: Praveen Rao praveensinghrao@outlook.com
 Co-authored-by: Sherlock Huang baihan.huang@gmail.com
 Co-authored-by: Alex Zinoviev alexander.zinoviev@me.com
 Co-authored-by: Dmitri Smirnov dmitrism@microsoft.com
2015-07-01 16:13:56 -07:00
Yueh-Hsuan Chiang
62a8fd154a Make stringappend_test runnable in ROCKSDB_LITE
Summary: Make stringappend_test runnable in ROCKSDB_LITE

Test Plan: stringappend_test

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

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40593
2015-06-24 15:01:43 -07:00
Yueh-Hsuan Chiang
72cab88959 Block redis_test in ROCKSDB_LITE
Summary: Block redis_test in ROCKSDB_LITE as utilities not supported in ROCKSDB_LITE.

Test Plan: redis_test

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

Reviewed By: IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40587
2015-06-24 01:44:21 -07:00
Venkatesh Radhakrishnan
e1d3c7dbe4 Fixing valgrind error in checkpoint_test
Summary: Fixed a valgrind issue in checkpoint_test

Test Plan: valgrind on checkpoint_test

Reviewers: igor, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40455
2015-06-19 20:21:23 -07:00
Venkatesh Radhakrishnan
04251e1e3a Add wal files to Checkpoint for multiple column families.
Summary:
When there are multiple column families, the flush in
GetLiveFiles is not atomic, so that there are entries in the wal files
which are needed to get a consisten RocksDB. We now add the log files to
the checkpoint.

Test Plan:
CheckpointCF - This test forces more data to be written to
the other column families after the flush of the first column family but
before the second.

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

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40323
2015-06-19 16:08:31 -07:00
Yueh-Hsuan Chiang
4d6d47688c Block geodb_test in ROCKSDB_LITE
Summary:
Block geodb_test in ROCKSDB_LITE as geodb is not supported
in ROCKSDB_LITE

Test Plan: geodb_test

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

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40335
2015-06-18 15:57:19 -07:00
Yueh-Hsuan Chiang
eade498bda Block utilities/write_batch_with_index in ROCKSDB_LITE
Summary:
Block utilities/write_batch_with_index in ROCKSDB_LITE as we
don't include anly utilities in ROCKSDB_LITE

Test Plan: write_batch_with_index_test

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

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40347
2015-06-18 15:54:05 -07:00
Igor Canadi
760e9a94de Fail DB::Open() when the requested compression is not available
Summary:
Currently RocksDB silently ignores this issue and doesn't compress the data. Based on discussion, we agree that this is pretty bad because it can cause confusion for our users.

This patch fails DB::Open() if we don't support the compression that is specified in the options.

Test Plan: make check with LZ4 not present. If Snappy is not present all tests will just fail because Snappy is our default library. We should make Snappy the requirement, since without it our default DB::Open() fails.

Reviewers: sdong, MarkCallaghan, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D39687
2015-06-18 14:55:05 -07:00
Islam AbdelRahman
12e030a992 Use CompactRangeOptions for CompactRange
Summary:
This diff update DB::CompactRange to use RangeCompactionOptions instead of using multiple parameters
Old CompactRange is still available but deprecated

Test Plan:
make all check
make rocksdbjava
USE_CLANG=1 make all
OPT=-DROCKSDB_LITE make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D40209
2015-06-17 14:36:14 -07:00
Igor Canadi
821cff114e Re-generate WriteEntry on WBWIIterator::Entry()
Summary:
[This is the resubmit of D39813. Tests were failing, so I reverted the diff. I found the bug and I'm now resubmitting]

If we don't do this, any calls to Entry() after WBWI mutation will result in undefined behavior. We need to re-fetch the offset from the skip list and regenerate the new pointer (because string's base pointer can change while mutating).

Test Plan: COMPILE_WITH_ASAN=1 make write_batch_with_index_test && ./write_batch_with_index_test

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D39897
2015-06-10 12:57:38 -07:00
Igor Canadi
75222d130e Revert "Fix compile"
This reverts commit 51440f83ec.

Revert "Re-generate WriteEntry on WBWIIterator::Entry()"

This reverts commit 4949ef08db.
2015-06-10 11:05:27 -07:00
Igor Canadi
51440f83ec Fix compile
Summary: Ooops, sorry about this.

Test Plan: compiles

Reviewers: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D39885
2015-06-10 10:42:15 -07:00
Igor Canadi
4949ef08db Re-generate WriteEntry on WBWIIterator::Entry()
Summary: If we don't do this, any calls to Entry() after WBWI mutation will result in undefined behavior. We need to re-fetch the offset from the skip list and regenerate the new pointer (because string's base pointer can change while mutating).

Test Plan: COMPILE_WITH_ASAN=1 make write_batch_with_index_test && ./write_batch_with_index_test

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D39813
2015-06-10 10:35:19 -07:00
sdong
e409d3d745 Make "make all" work for CYGWIN
Summary: Some test and benchmark codes don't build for CYGWIN. Fix it.

Test Plan: Build "make all" with TARGET_OS=Cygwin on cygwin and make sure it passes.

Reviewers: rven, yhchiang, anthony, igor, kradhakrishnan

Reviewed By: igor, kradhakrishnan

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D39711
2015-06-09 16:36:07 -07:00
Igor Canadi
62c3a95796 Add test for iteration+mutation of WBWI
Summary: We should support use-cases that mutate WBWI while they're iterating it. This diff adds a unit test to check this behavior.

Test Plan: this is a test

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D39501
2015-06-09 13:10:31 -07:00
Islam AbdelRahman
643bbbf081 Use nullptr for default compaction_filter_factory
Summary:
Replacing the default value for compaction_filter_factory and compaction_filter_factory_v2 to be nullptr instead of DefaultCompactionFilterFactory / DefaultCompactionFilterFactoryV2
The reason for this is to be able to determine easily if we have compaction filter factory or not without depending on RTTI

Test Plan: make check

Reviewers: yoshinorim, ott, igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D39693
2015-06-08 16:34:26 -07:00
sdong
21f2492ac0 Fix CYGWin release build
Summary: Change from one std::to_string() to ToString() for Cygwin build

Test Plan: Build it under cygwin

Reviewers: rven, anthony, IslamAbdelRahman, igor, kradhakrishnan

Reviewed By: igor, kradhakrishnan

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D39657
2015-06-08 11:35:22 -07:00
agiardullo
ca8b85ac04 better document max_write_buffer_number_to_maintain
Test Plan: compile

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D39285
2015-06-02 21:24:19 -07:00
sdong
4266d4fd90 Allow users to migrate to options.level_compaction_dynamic_level_bytes=true using CompactRange()
Summary: In DB::CompactRange(), change parameter "reduce_level" to "change_level". Users can compact all data to the last level if needed. By doing it, users can migrate the DB to options.level_compaction_dynamic_level_bytes=true.

Test Plan: Add a unit test for it.

Reviewers: yhchiang, anthony, kradhakrishnan, igor, rven

Reviewed By: rven

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D39099
2015-06-01 18:21:14 -07:00
Igor Canadi
4c181f08bc Fix compile on darwin
Summary: As title

Test Plan: make check

Reviewers: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D39243
2015-05-30 12:25:45 -04:00
agiardullo
dc9d70de65 Optimistic Transactions
Summary: Optimistic transactions supporting begin/commit/rollback semantics.  Currently relies on checking the memtable to determine if there are any collisions at commit time.  Not yet implemented would be a way of enuring the memtable has some minimum amount of history so that we won't fail to commit when the memtable is empty.  You should probably start with transaction.h to get an overview of what is currently supported.

Test Plan: Added a new test, but still need to look into stress testing.

Reviewers: yhchiang, igor, rven, sdong

Reviewed By: sdong

Subscribers: adamretter, MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D33435
2015-05-29 14:36:35 -07:00
agiardullo
711465ccec API to fetch from both a WriteBatchWithIndex and the db
Summary:
Added a couple functions to WriteBatchWithIndex to make it easier to query the value of a key including reading pending writes from a batch.  (This is needed for transactions).

I created write_batch_with_index_internal.h to use to store an internal-only helper function since there wasn't a good place in the existing class hierarchy to store this function (and it didn't seem right to stick this function inside WriteBatchInternal::Rep).

Since I needed to access the WriteBatchEntryComparator, I moved some helper classes from write_batch_with_index.cc into write_batch_with_index_internal.h/.cc.  WriteBatchIndexEntry, ReadableWriteBatch, and WriteBatchEntryComparator are all unchanged (just moved to a different file(s)).

Test Plan: Added new unit tests.

Reviewers: rven, yhchiang, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D38037
2015-05-11 14:51:51 -07:00
Igor Canadi
50eab9cf30 Fix BackupEngine
Summary:
In D28521 we removed GarbageCollect() from BackupEngine's constructor. The reason was that opening BackupEngine on HDFS was very slow and in most cases we didn't have any garbage. We allowed the user to call GarbageCollect() when it detects some garbage files in his backup directory.

Unfortunately, this left us vulnerable to an interesting issue. Let's say we started a backup and copied files {1, 3} but the backup failed. On another host, we restore DB from backup and generate {1, 3, 5}. Since {1, 3} is already there, we will not overwrite. However, these files might be from a different database so their contents might be different. See internal task t6781803 for more info.

Now, when we're copying files and we discover a file already there, we check:
1. if the file is not referenced from any backups, we overwrite the file.
2. if the file is referenced from other backups AND the checksums don't match, we fail the backup. This will only happen if user is using a single backup directory for backing up two different databases.
3. if the file is referenced from other backups AND the checksums match, it's all good. We skip the copy and go copy the next file.

Test Plan: Added new test to backupable_db_test. The test fails before this patch.

Reviewers: sdong, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D37599
2015-05-07 17:39:19 -07:00