Summary:
When memtable is full it calls the registered callback. That callback then registers column family as needing the flush. Every write checks if there are some column families that need to be flushed. This completely eliminates the need for MakeRoomForWrite() function and simplifies our Write code-path.

There is some complexity with the concurrency when the column family is dropped. I made it a bit less complex by dropping the column family from the write thread in https://reviews.facebook.net/D22965. Let me know if you want to discuss this.

Test Plan: make check works. I'll also run db_stress with creating and dropping column families for a while.

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23067

Summary:
See t5106397.

Also, few more changes:
1. in unit tests, the assumption is that writes will be dropped when there is no space left on device. I changed the wording around it.
2. InvalidArgument() errors are only when user-provided arguments are invalid. When the file is corrupted, we need to return Status::Corruption

Test Plan: make check

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23145

Summary: as title

Test Plan: make rocksdbjava

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23193

Summary: print qps in summary

Test Plan: ./cache_bench

Reviewers: yhchiang, ljin, sdong, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23079

Summary: Correct some comments and typos in RocksDB.

Test Plan: Inspection

Reviewers: sdong, igor

Reviewed By: igor

Differential Revision: https://reviews.facebook.net/D23133

Summary:
Added the following statistics to BackupableDB:

1. Number of successful and failed backups in class BackupStatistics
2. Time taken to do a backup
3. Number of files in a backup

1 is implemented in the BackupStatistics class
2 and 3 are added in the BackupMeta and BackupInfo class

Test Plan:
1 can be tested using BackupStatistics::ToString(),
2 and 3 can be tested in the BackupInfo class

Reviewers: sdong, igor2, ljin, igor

Reviewed By: igor

Differential Revision: https://reviews.facebook.net/D22785

Summary:
In column family's SanitizeOptions() [1], we make sure that min_write_buffer_number_to_merge is normal value. However, this test depended on the fact that setting min_write_buffer_number_to_merge to be bigger than max_write_buffer_number will cause a deadlock. I'm not sure how it worked before.

This diff fixes it by scheduling sleeping background task, which will actually block any attempts of flushing.

[1] https://github.com/facebook/rocksdb/blob/master/db/column_family.cc#L104

Test Plan: the test works now

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23103

Summary: To follow the coding convention and make sure when passing reference as a parameter it is also const, pass MergeContext as a pointer to mem tables.

Test Plan: make all check

Reviewers: ljin, igor

Reviewed By: igor

Subscribers: leveldb, dhruba, yhchiang

Differential Revision: https://reviews.facebook.net/D23085

Summary: Avoid creating unnecessary sst files while db opening

Test Plan: make all check

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: zagfox, yhchiang, ljin, leveldb

Differential Revision: https://reviews.facebook.net/D20661

Summary: I abandoned https://reviews.facebook.net/D18789, but I wrote a good unit test there, so let's check it in. :)

Test Plan: this is test

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22827

Summary:
The compilers we use treat char as signed. However, this is not guarantee of C standard and some compilers (for ARM platform for example), treat char as unsigned. Code that assumes that char is either signed or unsigned is wrong.

This change explicitly casts the char to signed version. This will not break any of our use cases on x86, which, I believe are all of them. In case somebody out there is using RocksDB on ARM AND using bloom filters, they're going to have a bad time. However, it is very unlikely that this is the case.

Test Plan: sanity test with previous commit (with new sanity test)

Reviewers: yhchiang, ljin, sdong

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D22767

Summary: removed reference to options in WriteBatch and DBImpl::Get()

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23049

Summary:
1. add db statistics
2. write out batch every millionth write

Test Plan: unit tests

Reviewers: ljin, sdong, yinwang

Reviewed By: yinwang

Differential Revision: https://reviews.facebook.net/D22755

Summary: as title

Test Plan: make release

Reviewers: igor

Differential Revision: https://reviews.facebook.net/D23073

Summary: as title

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23007

Summary: ...

Test Plan: Can't repro the test failure, but let's see what jenkins says

Reviewers: zagfox, sdong, ljin

Reviewed By: sdong, ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23061

Summary:
all shared_ptrs are in immutable_options now. This will also make
options assignment a little cheaper

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23001

Summary:
I found it is almost impossible to get rid of this function in a single
batch. I will take a step by step approach

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22995

Summary:
When we have multiple column families, users can issue Flush() on every column families to make sure everything is flushes, even if some of them might be empty. By skipping the waiting for empty cases, it can be greatly speed up.

Still wait for people's comments before writing unit tests for it.

Test Plan: Will write a unit test to make sure it is correct.

Reviewers: ljin, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D22953

Summary:
Introducing WriteController, which is a source of truth about per-DB write delays. Let's define an DB epoch as a period where there are no flushes and compactions (i.e. new epoch is started when flush or compaction finishes). Each epoch can either:
* proceed with all writes without delay
* delay all writes by fixed time
* stop all writes

The three modes are recomputed at each epoch change (flush, compaction), rather than on every write (which is currently the case).

When we have a lot of column families, our current pull behavior adds a big overhead, since we need to loop over every column family for every write. With new push model, overhead on Write code-path is minimal.

This is just the start. Next step is to also take care of stalls introduced by slow memtable flushes. The final goal is to eliminate function MakeRoomForWrite(), which currently needs to be called for every column family by every write.

Test Plan: make check for now. I'll add some unit tests later. Also, perf test.

Reviewers: dhruba, yhchiang, MarkCallaghan, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22791

Summary:
1. Make filter_block.h a base class. Derive block_based_filter_block and full_filter_block. The previous one is the traditional filter block. The full_filter_block is newly added. It would generate a filter block that contain all the keys in SST file.

2. When querying a key, table would first check if full_filter is available. If not, it would go to the exact data block and check using block_based filter.

3. User could choose to use full_filter or tradional(block_based_filter). They would be stored in SST file with different meta index name. "filter.filter_policy" or "full_filter.filter_policy". Then, Table reader is able to know the fllter block type.

4. Some optimizations have been done for full_filter_block, thus it requires a different interface compared to the original one in filter_policy.h.

5. Actual implementation of filter bits coding/decoding is placed in util/bloom_impl.cc

Benchmark: base commit 1d23b5c4
Command:
db_bench --db=/dev/shm/rocksdb --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --write_buffer_size=134217728 --max_write_buffer_number=2 --target_file_size_base=33554432 --max_bytes_for_level_base=1073741824 --verify_checksum=false --max_background_compactions=4 --use_plain_table=0 --memtablerep=prefix_hash --open_files=-1 --mmap_read=1 --mmap_write=0 --bloom_bits=10 --bloom_locality=1 --memtable_bloom_bits=500000 --compression_type=lz4 --num=393216000 --use_hash_search=1 --block_size=1024 --block_restart_interval=16 --use_existing_db=1 --threads=1 --benchmarks=readrandom —disable_auto_compactions=1
Read QPS increase for about 30% from 2230002 to 2991411.

Test Plan:
make all check
valgrind db_test
db_stress --use_block_based_filter = 0
./auto_sanity_test.sh

Reviewers: igor, yhchiang, ljin, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D20979

fix comments

replace hard-coded number with named variable

Cleanups from static analysis

typo improvement

Summary: 1. A benchmark for cache

Test Plan: ./cache_bench

Reviewers: yhchiang, dhruba, sdong, igor, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22809

Summary: If we drop column family only from (single) write thread, we can be sure that nobody will drop the column family while we're writing (and our mutex is released). This greatly simplifies my patch that's getting rid of MakeRoomForWrite().

Test Plan: make check, but also running stress test

Reviewers: ljin, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22965

Summary:
That way we can see when this graph goes up and be happy.

Couple of changes:
1. title
2. fix db_bench to delete column families before deleting the DB. this was asserting when compiled in debug mode
3. don't sync manifest when disableDataSync. We discussed this offline. I can move it to separate diff if you'd like

Test Plan: ran it

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22815

Summary: as title

Test Plan: make release

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22935