Summary:
Currently, transactions can fail even if there is no actual write conflict.  This is due to relying on only the memtables to check for write-conflicts.  Users have to tune memtable settings to try to avoid this, but it's hard to figure out exactly how to tune these settings.

With this diff, TransactionDB will use both memtables and SST files to determine if there are any write conflicts.  This relies on the fact that BlockBasedTable stores sequence numbers for all writes that happen after any open snapshot.  Also, D50295 is needed to prevent SingleDelete from disappearing writes (the TODOs in this test code will be fixed once the other diff is approved and merged).

Note that Optimistic transactions will still rely on tuning memtable settings as we do not want to read from SST while on the write thread.  Also, memtable settings can still be used to reduce how often TransactionDB needs to read SST files.

Test Plan: unit tests, db bench

Reviewers: rven, yhchiang, kradhakrishnan, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb, yoshinorim

Differential Revision: https://reviews.facebook.net/D50475

Summary: For Transactions, we want to start using the SST files to do write conflict checking.  To do this, we need to make sure that compaction never removes all writes if an earlier snapshot exists.  So I had to change the way we process SingleDeletes to sometimes leave a SingleDelete behind when we encounter a Put followed by a SingleDelete.  See the comments in this diff for a more detailed explanation.

Test Plan: added more unit tests

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

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50295

Summary:
This patch fix a race condition in persisting options which will cause a crash when:

* Thread A obtain cf options and start to persist options based on that cf options.
* Thread B kicks in and finish DropColumnFamily and delete cf_handle.
* Thread A wakes up and tries to finish the persisting options and crashes.

Test Plan: Add a test in column_family_test that can reproduce the crash

Reviewers: anthony, IslamAbdelRahman, rven, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51717

Summary:
D51183 was reverted due to breaking the LITE build.

This diff is the same as D51183 but with a fix for the LITE BUILD(D51693)

Test Plan: run all unit tests

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51711

This reverts commit ec704aaf for it broke RocksDB LITE build.

Summary:
D50475 enables using SST files for transaction write-conflict checking.  In order for this to work, we need to make sure not to compact out SingleDeletes when there is an earlier transaction snapshot(D50295).  If there is a long-held snapshot, this could reduce the benefit of the SingleDelete optimization.

This diff allows Transactions to mark snapshots as being used for write-conflict checking.  Then, during compaction, we will be able to optimize SingleDeletes better in the future.

This diff adds a flag to SnapshotImpl which is used by Transactions.  This diff also passes the earliest write-conflict snapshot's sequence number to CompactionIterator.  This diff does not actually change Compaction (after this diff is pushed, D50295 will be able to use this information).

Test Plan: no behavior change, ran existing tests

Reviewers: rven, kradhakrishnan, yhchiang, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51183

This reverts commit 2fa3ed51. It breaks RocksDB lite build

Summary:
This patch fix a race condition in persisting options which will cause a crash when:

* Thread A obtain cf options and start to persist options based on that cf options.
* Thread B kicks in and finish DropColumnFamily and delete cf_handle.
* Thread A wakes up and tries to finish the persisting options and crashes.

Test Plan: Add a test in column_family_test that can reproduce the crash

Reviewers: anthony, IslamAbdelRahman, rven, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51609

Summary:
Fixes T8781168.

Added a new function EnableAutoCompactions in db.h to be publicly
avialable.  This allows compaction to be re-enabled after disabling it via
SetOptions

Refactored code to set the dbptr earlier on in TransactionDB::Open and DB::Open
Temporarily disable auto_compaction in TransactionDB::Open until dbptr is set to
prevent race condition.

Test Plan:
Ran make all check

verified fix on myrocks side:
was able to reproduce the seg fault with
../tools/mysqltest.sh --mem --force rocksdb.drop_table

method was to manually sleep the thread after DB::Open but before TransactionDB ptr was
assigned in transaction_db_impl.cc:
  DB::Open(db_options, dbname, column_families_copy, handles, &db);
  clock_t goal = (60000 * 10) + clock();
  while (goal > clock());
  ...dbptr(aka rdb) gets assigned below

verified my changes fixed the issue.

Also added unit test 'ToggleAutoCompaction' in transaction_test.cc

Reviewers: hermanlee4, anthony

Reviewed By: anthony

Subscribers: alex, dhruba

Differential Revision: https://reviews.facebook.net/D51147

DB to only flush the column family with the largest memtable while option.db_write_buffer_size is hit

Summary: When option.db_write_buffer_size is hit, we currently flush all column families. Move to flush the column family with the largest active memt table instead. In this way, we can avoid too many small files in some cases.

Test Plan: Modify test DBTest.SharedWriteBuffer to work with the updated behavior

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

Reviewed By: igor

Subscribers: march, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51291

Summary: Handle multiple calls to DBImpl::PauseBackgroundWork() and DBImpl::ContinueBackgroundWork()

Test Plan: rocksdb.information_schema handles this case.

Reviewers: igor

Reviewed By: igor

Subscribers: hermanlee4, jkedgar, dhruba

Differential Revision: https://reviews.facebook.net/D50781

Summary:
Since level 0 files can overlap, two level 0 compactions cannot
run in parallel. Compact files needs to check this before running a
compaction.

Test Plan: CompactFilesTest.L0ConflictsFiles

Reviewers: igor, IslamAbdelRahman, anthony, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50079

Summary:
There's no need for WriteImpl to flatten the write batch group
into a single WriteBatch if the WAL is disabled.  This diff moves the
flattening into the WAL step, and skips flattening entirely if it isn't
needed.  It's good for about 5% speedup on a multi-threaded workload
with no WAL.

This diff also adds clarifying comments about the chance for partial
failure of WriteBatchInternal::InsertInto, and always sets bg_error_ if
the memtable state diverges from the logged state or if a WriteBatch
succeeds only partially.

Benchmark for speedup:
  db_bench -benchmarks=fillrandom -threads=16 -batch_size=1 -memtablerep=skip_list -value_size=0 --num=200000 -level0_slowdown_writes_trigger=9999 -level0_stop_writes_trigger=9999 -disable_auto_compactions --max_write_buffer_number=8 -max_background_flushes=8 --disable_wal --write_buffer_size=160000000

Test Plan: asserts + make check

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D50583

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

Summary:
MyRocks testing found an issue that while iterating over keys
that are outside the prefix, sometimes wrong results were seen for keys
outside the prefix. We now tighten the range of keys seen with a new
read option called prefix_seen_at_start. This remembers the starting
prefix and then compares it on a Next for equality of prefix. If they
are from a different prefix, it sets valid to false.

Test Plan: PrefixTest.PrefixValid

Reviewers: IslamAbdelRahman, sdong, yhchiang, anthony

Reviewed By: anthony

Subscribers: spetrunia, hermanlee4, yoshinorim, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50211

Summary:
This patch adds GetAggregatedIntProperty() that returns the aggregated
value from all CFs

Test Plan: Added a test in db_test

Reviewers: igor, sdong, anthony, IslamAbdelRahman, rven

Reviewed By: rven

Subscribers: rven, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49497

Summary:
Update DB::AddFile() restrictions to be
  - Key range in loaded table file don't overlap with existing keys or tombstones in DB.
  - No other writes happen during AddFile call.

The updated AddFile() will verify that the file key range don't overlap with any keys or tombstones in the DB, and then add the file to L0

Test Plan: unit tests

Reviewers: igor, rven, anthony, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: adsharma, ameyag, dhruba

Differential Revision: https://reviews.facebook.net/D49233

Summary:
CreateLoggerFromOptions have some parameters like  db_log_dir and env, these parameters are redundant since they already exist in DBOptions

this patch remove the redundant parameters and expose CreateLoggerFromOptions to users

Test Plan: make check

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

Reviewed By: sdong

Subscribers: dhruba, hermanlee4

Differential Revision: https://reviews.facebook.net/D49713

Summary: Run "make format" for some recent commits.

Test Plan: Build and run tests

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49707

Summary:
An uninitialized parameter was being passed into the call to fetch the table
properties during the compaction notification callbacks.

Test Plan:
Build it with myrocks and verify unit test passed.
Run unit tests.

Reviewers: rven, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D49635

Fail recovery if filter provides more records than original and corresponding unit-test, fix naming conventions

Handle multiple batches in single log record - allow app to return a new batch + allow app to return corrupted record status

Summary: As above.

Test Plan: USE_CLANG=1 make check -j

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48981

Soon our behavior will depend on more than just whther we are in
kAbsoluteConsistency or not.
Signed-off-by: NSage Weil <sage@redhat.com>

We will need the log number to validate the recycle-style CRCs.  The log
is helpful for debugging, but optional, as not all callers have it.
Signed-off-by: NSage Weil <sage@redhat.com>

When we recycle log files, we need to mix the log number into the CRC
for each record.  Note that for logs that don't get recycled (like the
manifest), we always pass a log_number of 0 and false.
Signed-off-by: NSage Weil <sage@redhat.com>

If log recycling is enabled, put old WAL files on a recycle queue instead of
deleting them.  When we need a new log file, take a recycled file off the
list if one is available.
Signed-off-by: NSage Weil <sage@redhat.com>

We can't recycle the files if they are being archived.
Signed-off-by: NSage Weil <sage@redhat.com>

Summary: In MyRocks, it is sometimes important to get propeties only for the subset of the database. This diff implements the API in RocksDB.

Test Plan: ran the GetPropertiesOfTablesInRange

Reviewers: rven, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48651

Summary:
Add rocksdb.num-running-compactions and rocksdb.num-running-flushes
to GetIntProperty() that reports the number of currently running
compactions / flushes.

Test Plan: augmented existing tests in db_test

Reviewers: igor, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D48693

Summary:
Add kill points in:
1. after creating a file
2. before writing a manifest record
3. before syncing manifest
4. before creating a new current file
5. after creating a new current file

Test Plan: Run all current tests.

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

Reviewed By: kradhakrishnan

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48855

Summary:
We are cleaning up dependencies.
This diff takes a first step at moving memtable files to their own
directory called memtable. In future diffs, we will move other memtable
files from db to memtable.

Test Plan: make check

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D48915

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

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

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

Summary: It would be nice to have and access to table properties in compaction callbacks. In MyRocks project, it will make possible to update optimizer statistics online.

Test Plan: ran the unit test. Ran myrocks with the new way of collecting stats.

Reviewers: igor, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48267

Summary: Pass column family ID through TablePropertiesCollectorFactory::CreateTablePropertiesCollector() so that users can identify which column family this file is for and handle it differently.

Test Plan: Add unit test scenarios in tests related to table properties collectors to verify the information passed in is correct.

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

Reviewed By: IslamAbdelRahman

Subscribers: yoshinorim, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48411

Summary:
	Handle SST files with both ".sst" and ".ldb" suffix.
	This enables user to migrate from leveldb to rocksdb.

Test Plan:
        Added unit test with DB operating on SSTs with names schema.
        See db/dc_test.cc:SSTsWithLdbSuffixHandling for details

Reviewers: yhchiang, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D48003