Summary: Our profile shows that in one of the applications, 5% of the CPU costs of PlainTableBuilder::Add() are spent on std::string stacks. By this simple change, we avoid this global reusable string. Also, we avoid another call of file appending, which probably gives another 2%.
Test Plan: make all check
Reviewers: haobo, ljin
Reviewed By: haobo
CC: igor, yhchiang, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D17601
Summary: This will allow us to disable them completely for iOS or for better performance
Test Plan: will run make all check
Reviewers: igor, haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17511
Summary:
Move PlainTableIterator's copied key from std::string local buffer to avoid paying the extra costs in std::string related to sharing. Reuse the same buffer class in DbIter. Move the class to dbformat.h.
This patch improves iterator performance significantly. Running this benchmark:
./table_reader_bench --num_keys2=17 --iterator --plain_table --time_unit=nanosecond
The average latency is improved to about 750 nanoseconds from 1100 nanoseconds.
Test Plan:
Add a unit test.
make all check
Reviewers: haobo, ljin
Reviewed By: haobo
CC: igor, yhchiang, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D17547
Summary:
In total order mode, iterator's seek() shouldn't check total order.
Also some cleaning up about checking null for shared pointers. I don't know the behavior before it.
This bug was reported by @igor.
Test Plan: test plain_table_db_test
Reviewers: ljin, haobo, igor
Reviewed By: igor
CC: yhchiang, dhruba, igor, leveldb
Differential Revision: https://reviews.facebook.net/D17391
Summary:
By constraining the probes within cache line(s), we can improve the
cache miss rate thus performance. This probably only makes sense for
in-memory workload so defaults the option to off.
Numbers and comparision can be found in wiki:
https://our.intern.facebook.com/intern/wiki/index.php/Ljin/rocksdb_perf/2014_03_17#Bloom_Filter_Study
Test Plan: benchmarked this change substantially. Will run make all check as well
Reviewers: haobo, igor, dhruba, sdong, yhchiang
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17133
Summary:
Previous code had two bugs:
* didn't initialize the table_magic_number_ explicitly -- as a
result a random junk number is stored for table_magic_number_, making
HasInitializedMagicNumber() always return true.
* if condition is inconrrect in set_table_magic_number(), and the return value is not checked.
I replace if-else by a stronger requirement enforced by assert().
Test Plan:
Previous sst_dump failed to work.
After the fix, things back to normal.
Reviewers: yhchiang
CC: haobo, sdong, igor, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D17055
Summary:
I'm cleaning up some code preparing for the big diff review tomorrow. This is the first part of the cleanup.
Changes are mostly cosmetic. The goal is to decrease amount of code difference between columnfamilies and master branch.
This diff also fixes race condition when dropping column family.
Test Plan: Ran db_stress with variety of parameters
Reviewers: dhruba, haobo
Differential Revision: https://reviews.facebook.net/D16833
Summary:
(1) Fix SanitizeOptions() to also check HashLinkList. The current
dynamic case just happens to work because the 2 classes have the same
layout.
(2) Do not delete SliceTransform object in HashSkipListFactory and
HashLinkListFactory destructor. Reason: SanitizeOptions() enforces
prefix_extractor and SliceTransform to be the same object when
Hash**Factory is used. This makes the behavior strange: when
Hash**Factory is used, prefix_extractor will be released by RocksDB. If
other memtable factory is used, prefix_extractor should be released by
user.
Test Plan: db_bench && make asan_check
Reviewers: haobo, igor, sdong
Reviewed By: igor
CC: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D16587
Summary:
Previous we did rough estimation of subindex size, which in worst case may result in array reallocation.
This patch aims to get the exact size and avoid any reallocation.
Test Plan: make all check
Reviewers: sdong, dhruba, haobo
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16125
Summary: The assert was pointless since if if prefix is the same as the whole key, assertion will surely fail. Reason behind is when performing the internal key comparison, if user keys are the same, *key with smaller transaction id* wins.
Test Plan: make -j32 && make check
Reviewers: sdong, dhruba, haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16551
Summary:
this is the key component extracted from diff: https://reviews.facebook.net/D14271
I separate it to a dedicated patch to make the review easier.
Test Plan: added a unit test and passed it.
Reviewers: haobo, sdong, dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16245
Summary:
Due to a bad merge of D14163 and D14001 before checking in D14001, "direction_ = kForward;" in MergeIterator::Seek() was deleted my mistake (in commit b135d01e7b ). It will generate wrong results or assert failure after the sequence of Prev() (or SeekToLast()), Seek() and Prev().
Fix it
Test Plan: make all check
Reviewers: igor, haobo, dhruba
Reviewed By: igor
CC: yhchiang, i.am.jin.lei, ljin, leveldb
Differential Revision: https://reviews.facebook.net/D16527
Summary:
BinarySearchIndex didn't use unique_ptr to guard the block object nor
delete it in destructor, leading to valgrind failure for "definite
memory leak".
Test Plan:
re-ran the failed valgrind test cases
Summary:
My last diff was developed in MacOS but in devserver environment error occurs.
I dug into the problem and found the way we calcuate approximate data size is pretty out-of-date. We can use table properties to get more accurate results.
Test Plan: ran ./table_test and passed
Reviewers: igor, dhruba, haobo, sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16509
Summary:
This patch introduced a new table options that allows us to make
block-based table's index pluggable.
To support that new features:
* Code has been refacotred to be more flexible and supports this option well.
* More documentation is added for the existing obsecure functionalities.
* Big surgeon on DataBlockReader(), where the logic was really convoluted.
* Other small code cleanups.
The pluggablility will mostly affect development of internal modules
and won't change frequently, as a result I intentionally avoid
heavy-weight patterns (like factory) and try to make it simple.
Test Plan: make all check
Reviewers: haobo, sdong
Reviewed By: sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16395
Summary:
Previous code is too convoluted and I must be drunk for letting
such code to be written without a second thought.
Thanks to the discussion with @sdong, I added the `Options` when
generating the flusher, thus avoiding the tricks.
Just FYI: I resisted to add Options in flush_block_policy.h since I
wanted to avoid cyclic dependencies: FlushBlockPolicy dpends on Options
and Options also depends FlushBlockPolicy... While I appreciate my
effort to prevent it, the old design turns out creating more troubles than
it tried to avoid.
Test Plan: ran ./table_test
Reviewers: sdong
Reviewed By: sdong
CC: sdong, leveldb
Differential Revision: https://reviews.facebook.net/D16503
Summary:
Found some function follows camel style. When naming funciton, we have two styles:
Trivially expose internal data in readonly mode: `all_lower_case()`
Regular function: `CapitalizeFirstLetter()`
I renames these functions.
Test Plan: make -j32
Reviewers: haobo, sdong, dhruba, igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16383
Summary:
PlainTable::Next() should pass the error message from ReadKey(). Now it would return a wrong error message.
Also improve the messages of status when failing to read
Test Plan: make all check
Reviewers: ljin, kailiu, haobo
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16365
Summary: This bug caused server crash issues because the filter block is too big and kept purging out of cache.
Test Plan: Wrote a new unit tests to make sure it works.
Reviewers: dhruba, haobo, igor, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16221
Summary: Provide a public API for users to access the table properties for each SSTable.
Test Plan: Added a unit tests to test the function correctness under differnet conditions.
Reviewers: haobo, dhruba, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16083
Summary: Fix table_reader_bench after some interface changes. Add it to make to avoid future breaking
Test Plan: make table_reader_bench and run it with different options.
Reviewers: kailiu, haobo
Reviewed By: haobo
CC: igor, leveldb
Differential Revision: https://reviews.facebook.net/D16107
Summary:
1. Add some more implementation-aware tests for PlainTable
2. move from a hard-coded one index per 16 rows in one prefix to a configurable number. Also, make hash table ratio = 0 means binary search only. Also fixes some divide 0 risks.
3. Explicitly support total order (only use binary search)
4. some code cleaning up.
Test Plan: make all check
Reviewers: haobo, kailiu
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16023
Summary:
The change to the public behavior:
* When opening a DB or creating new column family client gets a ColumnFamilyHandle.
* As long as column family handle is alive, client can do whatever he wants with it, even drop it
* Dropped column family can still be read from (using the column family handle)
* Added a new call CloseColumnFamily(). Client has to close all column families that he has opened before deleting the DB
* As soon as column family is closed, any calls to DB using that column family handle will fail (also any outstanding calls)
Internally:
* Ref-counting ColumnFamilyData
* New thread-safety for ColumnFamilySet
* Dropped column families are now completely dropped and their memory cleaned-up
Test Plan: added some tests to column_family_test
Reviewers: dhruba, haobo, kailiu, sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16101
Summary: We'll need the prefix seek support for property aggregation.
Test Plan: make all check
Reviewers: haobo, sdong, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15963
Summary:
In MacOS, I got issue with `Footer`'s default constructor, which initialized the magic number with some random number instead of 0.
With investigation, I found we forgot to make the kInvalidTableMagicNumber to be static. As a result, kInvalidTableMagicNumber was assgined to `table_magic_number_` before it is initialized (which will be populated with random number).
Test Plan: passed current unit tests; also passed the unit tests for the incoming diff which used the default footer.
Reviewers: yhchiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16077
Summary:
* Fixed the compression state array size bug.
* Temporarily disable running `DoCompressionTest()` against bzip, which will fail the test.
Test Plan: make && ./table_test
Reviewers: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16065
Summary:
We are going to expose properties of all tables to end users through "some" db interface.
However, current design doesn't naturally fit for this need, which is because:
1. If a table presents in table cache, we cannot simply return the reference to its table properties, because the table may be destroy after compaction (and we don't want to hold the ref of the version).
2. Copy table properties is OK, but it's slow.
Thus in this diff, I change the table reader's interface to return a shared pointer (for const table properties), instead a const refernce.
Test Plan: `make check` passed
Reviewers: haobo, sdong, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15999
