Summary: This patch makes Table and TableBuilder a abstract class and make all the implementation of the current table into BlockedBasedTable and BlockedBasedTable Builder.

Test Plan: Make db_test.cc to work with block based table. Add a new test simple_table_db_test.cc where a different simple table format is implemented.

Reviewers: dhruba, haobo, kailiu, emayanke, vamsi

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13521

Summary: assert(Overlap) significantly slows down the benchmark. Ignore assertions when executing blob_store_bench.

Test Plan: Ran the benchmark

Reviewers: dhruba, haobo, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13737

Summary: Apparently C++ doesn't like it if you copy around its atomic<> variables. When running a benchmark for a longer time, benchmark used to stall. Changed WorkerThread in config to WorkerThread*. It works now.

Test Plan: Ran benchmark

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13731

Summary:
1. Added a new option that support user-defined table stats collection.
2. Added a deleted key stats collector in `utilities`

Test Plan:
Added a unit test for newly added code.
Also ran make check to make sure other tests are not broken.

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13491

Summary:
A latest valgrind test found a recently added unit test has memory leak,
which is because DB is not closed at the end of the test.

Test Plan: re-run the valgrind locally and make sure there's no memory leakage any more.

Reviewers: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13725

Summary:
When a Put fails, it can leave database in a messy state. We don't want to pretend that everything is OK when it may not be. We fail every write following the failed one.

I added checks for corruption to DBImpl::Write(). Is there anywhere else I need to add them?

Test Plan: Corruption unit test.

Reviewers: dhruba, haobo, kailiu

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13671

Summary:

This bug may affect the seek performance.

Test Plan:

make
make check

Also gdb into some index block builder to make sure the restart_block_interval is `1`.

Summary:

my fix patch introduced a new error in debug mode.

Test Plan:

`make` and `make release`

Summary: Fix the unused variable warning for `first` when running `make release`

Test Plan:
make
make check

Reviewers: dhruba, igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13695

Summary:
This is to simplify rocksdb public APIs and improve the code quality.
Created an additional parameter to ParseFileName for log sub type and improved the code for deleting a wal file.
Wrote exhaustive unit-tests in delete_file_test
Unification of other redundant APIs can be taken up in a separate diff

Test Plan: Expanded delete_file test

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13647

Summary:
Crash may occur during the flushes of more than two mem tables.

As the info log suggested, even when both were successfully flushed,
the recovery process still pick up one of the memtable's log for recovery.

This diff fix the problem by setting the correct "log number" in MANIFEST.

Test Plan: make test; deployed to leaf4 and make sure it doesn't result in crashes of this type.

Reviewers: haobo, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13659

Summary: Converted db_stress, db_repl_stress and db_bench to use gflags

Test Plan: I tested by printing out all the flags from old and new versions. Tried defaults, + various combinations with "interesting flags". Also, tested by running db_crashtest.py and db_crashtest2.py.

Reviewers: emayanke, dhruba, haobo, kailiu, sdong

Reviewed By: emayanke

CC: leveldb, xjin

Differential Revision: https://reviews.facebook.net/D13581

Summary:
Finally, arc diff works again! This has been sitting in my repo for a while.

I would like some comments on my BlobStore benchmark. We don't have to check this in.

Also, I don't do any fsync in the BlobStore, so this is all extremely fast. I'm not sure what durability guarantees we need from the BlobStore.

Test Plan: Nope

Reviewers: dhruba, haobo, kailiu, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13527

Summary:
I added max_size option in blobstore. Since we now know the maximum number of buckets we'll ever use, we can allocate an array of buckets and access its elements without use of any locks! Common case Get doesn't lock anything now.

Benchmarks on 16KB block size show no impact on speed, though.

Test Plan: unittests + benchmark

Reviewers: dhruba, haobo, kailiu

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13641

Summary: as title

Test Plan: make check; ./perf_context_test

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13629

Summary: as per Dhruba's suggestion

Test Plan: make all check; Seen the Id getting generated properly in db_repl_stress

Reviewers: dhruba, kailiu

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13635

Summary:
I have implemented a FreeList version that supports fragmented blob chunks. Each block gets allocated and freed in FIFO order. Since the idea for the blocks to be big, we will not take a big hit of non-sequential IO. Free list is also faster, taking only O(k) size in both free and allocate instead of O(N) as before.

See more info on the task: https://our.intern.facebook.com/intern/tasks/?t=2990558

Also, I'm taking Slice instead of const char * and size in Put function.

Test Plan: unittests

Reviewers: haobo, kailiu, dhruba, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13569

Summary:
Create a new type of file on startup if it doesn't already exist called DBID.
This will store a unique number generated from boost library's uuid header file.
The use-case is to identify the case of a db losing all its data and coming back up either empty or from an image(backup/live replica's recovery)
the key point to note is that DBID is not stored in a backup or db snapshot
It's preferable to use Boost for uuid because:
1) A non-standard way of generating uuid is not good
2) /proc/sys/kernel/random/uuid generates a uuid but only on linux environments and the solution would not be clean
3) c++ doesn't have any direct way to get a uuid
4) Boost is a very good library that was already having linkage in rocksdb from third-party
Note: I had to update the TOOLCHAIN_REV in build files to get latest verison of boost from third-party as the older version had a bug.
I had to put Wno-uninitialized in Makefile because boost-1.51 has an unitialized variable and rocksdb would not comiple otherwise. Latet open-source for boost is 1.54 but is not there in third-party. I have notified the concerned people in fbcode about it.
@kailiu : While releasing to third-party, an additional dependency will need to be created for boost in TARGETS file. I can help identify.

Test Plan:
Expand db_test to test 2 cases
1) Restarting db with Id file present - verify that no change to Id
2)Restarting db with Id file deleted - verify that a different Id is there after reopen
Also run make all check

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13587

Summary:
This is expected to solve the "gaps in transaction log iterator" problem.
* After a lot of observations on the gaps on the sigmafio machines I found that it is due to a race between log reader and writer always.
* So when we drop the wormhole subscription and refresh the iterator, the gaps are not there.
* It is NOT due to some boundary or corner case left unattended in the iterator logic because I checked many instances of the gaps against their log files with ldb. The log files are NOT corrupted also.
* The solution is to not allow the iterator to read incompletely written sequences and detect gaps inside itself and invalidate it which will cause the application to refresh the iterator normally and seek to the required sequence properly.
* Thus, the iterator can at least guarantee that it will not give any gaps.

Test Plan:
* db_test based log iterator tests
* db_repl_stress
* testing on sigmafio setup to see gaps go away

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13593

Summary: Per @haobo's request, rephrasing the comment for allocate

Test Plan: It's a comment!

Reviewers: haobo, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13575

Summary:

Previous the newly added test called NewBloomFilter without releasing it at the end of the test, which resulted in memory leak and was detected by valgrind.

Test Plan:

Ran valgrind test.

Summary: This caused Siying's unit test to fail.

Test Plan: Unittest

Reviewers: dhruba, kailiu, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13539

Fix Bug: iterator.Prev() or iterator.SeekToLast() might return the first element instead of the correct one

Summary:
Recent patch https://reviews.facebook.net/D11865 introduced a regression bug:

DBIter::FindPrevUserEntry(), which is called by DBIter::Prev() (and also implicitly if calling iterator.SeekToLast())  might do issue a seek when having skipped too many entries. If the skipped entry just before the seek() is a delete, the saved key is erased so that it seeks to the front, so Prev() would return the first element.

This patch fixes the bug by not doing seek() in DBIter::FindNextUserEntry() if saved key has been erased.

Test Plan: Add a test DBTest.IterPrevMaxSkip which would fail without the patch and would pass with the change.

Reviewers: dhruba, xjin, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13557

Summary:
This patch adds a option for universal compaction to allow us to only compress output files if the files compacted previously did not yet reach a specified ratio, to save CPU costs in some cases.

Compression is always skipped for flushing. This is because the size information is not easy to evaluate for flushing case. We can improve it later.

Test Plan:
add test
DBTest.UniversalCompactionCompressRatio1 and DBTest.UniversalCompactionCompressRatio12

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13467

Summary: As title.

Test Plan: Updated the unit tests to make sure new statistic is correctly written/read.

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13497

Summary: Allow ttl flag

Test Plan:
tested on my database that has merge operations and ttl

Revert Plan: OK

Task ID: #3038186

Reviewers: emayanke, dhruba, haobo

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13503

Summary:
Add appropriate LICENSE and Copyright message.

Test Plan:
make check

Reviewers:

CC:

Task ID: #

Blame Rev:

Summary:
Developing a capability for storing values on external backing file(s).

This is just a highly unoptimized first pass - supports:
1) Allocating some portion of external file to be used to store value
2) Freeing the range, enabling it to be reused by other values

As next steps, I plan to:
1) Create some kind of stress testing. Once I can measure stuff, I can focus on optimizing.
2) Optimize locking.
3) Optimize freelist data structure. Currently we have O(n) for both freeing and allocation.
4) Figure out how to do recovery.

Test Plan: Created a unit test.

Reviewers: dhruba, haobo, kailiu

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13389

Summary:

Formatted the PATENT file so that it's easier to read.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:

Summary:
Enable background flush thread in this patch and fix unit tests with:
(1) After background flush, schedule a background compaction if condition satisfied;
(2) Fix a bug that if universal compaction is enabled and number of levels are set to be 0, compaction will not be automatically triggered
(3) Fix unit tests to wait for compaction to finish instead of flush, before checking the compaction results.

Test Plan: pass all unit tests

Reviewers: haobo, xjin, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13461

Summary:
Added Patent information to the source code repository.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:

Summary:
Fix error in previous commit of 'ftruncate' to 'fallocate'.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:

Summary:
tmpfs might not support fallocate(). Fix unit test so that this
does not cause a unit test to fail.

Test Plan: ./env_test

Reviewers: emayanke, igor, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13455

Summary:
This is needed to make existing dbs be able to open and also because BytewiseComparator was not changed since leveldb.
The inverted order in the error message caused confusion prebiously

Test Plan: make; open existing db

Reviewers: leveldb, dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D13449

Summary:
* Logstore requests a valid change of reutrning an empty iterator and not an error in case of no log files.
* Changed the code to return the writebatch containing the sequence number requested from GetupdatesSince even if it lies in the middle. Earlier we used to return the next writebatch,. This also allows me oto guarantee that no files played upon by the iterator are redundant. I mean the starting log file has at least a sequence number >= the sequence number requested form GetupdatesSince.
* Cleaned up redundant logic in Iterator::Next and made a new function SeekToStartSequence for greater readability and maintainibilty.
* Modified a test in db_test accordingly
Please check the logic carefully and suggest improvements. I have a separate patch out for more improvements like restricting reader to read till written sequences.

Test Plan:
* transaction log iterator tests in db_test,
* db_repl_stress.
* rocks_log_iterator_test in fbcode/wormhole/rocksdb/test - 2 tests thriving on hacks till now can get simplified
* testing on the shadow setup for sigma with replication

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13437

Summary:
So far we only have key/value pairs as well as bloom filter stored in the
sst file.  It will be great if we are able to store more metadata about
this table itself, for example, the entry size, bloom filter name, etc.

This diff is the first step of this effort. It allows table to keep the
basic statistics mentioned in http://fburl.com/14995441, as well as
allowing writing user-collected stats to stats block.

After this diff, we will figure out the interface of how to allow user to collect their interested statistics.

Test Plan:
1. Added several unit tests.
2. Ran `make check` to ensure it doesn't break other tests.

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13419

Summary: When I debug the unit test failures when enabling background flush thread, I feel the function names can be made clearer for people to understand. Also, if the names are fixed, in many places, some tests' bugs are obvious (and some of those tests are failing). This patch is to clean it up for future maintenance.

Test Plan: Run test suites.

Reviewers: haobo, dhruba, xjin

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13431

Summary:
With this patch, when LRUCache.Insert() is called and the cache is full, it will first try to free up entries whose reference counter is 1 (would become 0 after remo\
ving from the cache). We do it in two passes, in the first pass, we only try to release those unreferenced entries. If we cannot free enough space after traversing t\
he first remove_scan_cnt_ entries, we start from the beginning again and remove those entries being used.

Test Plan: add two unit tests to cover the codes

Reviewers: dhruba, haobo, emayanke

Reviewed By: emayanke

CC: leveldb, emayanke, xjin

Differential Revision: https://reviews.facebook.net/D13377