Commit Graph

1226 Commits

Author SHA1 Message Date
SherlockNoMad
58379bfb55 remove division from histogramwidowing impl 2016-03-14 21:41:13 -07:00
SherlockNoMad
fd664a27b5 Fix Build Error 2016-03-11 22:56:25 -08:00
SherlockNoMad
54f6b9e162 Histogram Concurrency Improvement and Time-Windowing Support 2016-03-11 16:54:25 -08:00
agiardullo
790252805d Add multithreaded transaction test
Summary: Refactored db_bench transaction stress tests so that they can be called from unit tests as well.

Test Plan: run new unit test as well as db_bench

Reviewers: yhchiang, IslamAbdelRahman, sdong

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55203
2016-03-11 15:16:52 -08:00
Yi Wu
f71fc77b7c Cache to have an option to fail Cache::Insert() when full
Summary:
Cache to have an option to fail Cache::Insert() when full. Update call sites to check status and handle error.

I totally have no idea what's correct behavior of all the call sites when they encounter error. Please let me know if you see something wrong or more unit test is needed.

Test Plan: make check -j32, see tests pass.

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

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54705
2016-03-10 17:35:19 -08:00
Yueh-Hsuan Chiang
bf1c4089db Use pure if-then check instead of assert in EraseColumnFamilyInfo
Summary:
Use pure if-then check instead of assert in EraseColumnFamilyInfo
when the specified column family does not found in the cf_info_map_.
So the second deletion will be no op instead of crash.

Test Plan: existing test.

Reviewers: sdong, anthony, kradhakrishnan, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55023
2016-03-04 16:03:31 -08:00
Omar Sandoval
deb08b8226 Add parsing of missing DB options
Summary: There are a few options in struct DBOptions that aren't handled by options_helper.cc. Add those missing options so they can be used by GetDBOptionsFromString() and friends.

Test Plan: Updated options_test.cc, reran all tests.

Reviewers: sdong, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54603
2016-03-02 10:34:14 -08:00
Yi Wu
2568985ab3 IOStatsContext::ToString() add option to exclude zero counters
Summary: similar to D52809 add option to exclude zero counters.

Test Plan:
[yiwu@dev4504.prn1 ~/rocksdb] ./iostats_context_test
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from IOStatsContextTest
[ RUN      ] IOStatsContextTest.ToString
[       OK ] IOStatsContextTest.ToString (0 ms)
[----------] 1 test from IOStatsContextTest (0 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (0 ms total)
[  PASSED  ] 1 test.

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

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D54591
2016-02-23 10:26:24 -08:00
Andrew Kryczka
b046916656 Redo SyncPoints for flush while rolling test
Summary:
There was a race condition in the test where the rolling thread
acquired the mutex before the flush thread pinned the logger. Rather than add
more complicated synchronization to fix it, I followed Siying's suggestion to
use SyncPoint in the test code.

Comments in the LoadDependency() invocation explain the reason for each of the
sync points.

Test Plan:
Ran test 1000 times for tsan/asan. Will wait for all sandcastle tests
to finish before committing since this is a tricky test.

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54615
2016-02-22 21:32:19 -08:00
Yueh-Hsuan Chiang
79ca039eb4 Relax the check condition of prefix_extractor in CheckOptionsCompatibility
Summary:
Relax the check condition of prefix_extractor in CheckOptionsCompatibility
by allowing changing value from non-nullptr to nullptr or nullptr to
non-nullptr.

Test Plan:
options_test
options_util_test

Reviewers: sdong, anthony, IslamAbdelRahman, kradhakrishnan, gunnarku

Reviewed By: gunnarku

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54477
2016-02-19 14:42:24 -08:00
sdong
c7f1a8a468 Fix LITE build thread_local_test
Summary: Recent change break thread_local_test by introducing exception, which is disabled in LITE build. Fix it by disabling exception handling in LITE build.

Test Plan: Build with both of LITE and non-LITE

Reviewers: anthony, IslamAbdelRahman, yhchiang, kradhakrishnan, andrewkr

Reviewed By: andrewkr

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D54513
2016-02-19 13:57:18 -08:00
Dmitri Smirnov
d37d348da8 This addresses build issues on Windows
https://github.com/facebook/rocksdb/issues/1002
2016-02-19 12:29:54 -08:00
Islam AbdelRahman
6b2a047dfc Fix SstFileManager uninitialized data member
Summary: I have introduced max_allowed_space_ but did not initialize it

Test Plan: make check

Reviewers: sdong, yhchiang, anthony

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D54357
2016-02-18 11:25:19 -08:00
Yueh-Hsuan Chiang
a3db93c261 Remove the SyncPoint usage in the destructor of PosixEnv
Summary:
Remove the SyncPoint usage in the destructor of PosixEnv as none
of any active tests is using it.

SyncPoint is a test-only utility class, and it's a static varible.
As a result, using SyncPoint in the destructor of PosixEnv will
make default Env depends on SyncPoint.  Removing such dependency
could solve the problem crash issue only reproducable in Mac
environment.

Test Plan: OPT=-DTRAVIS V=1 make -j4 check on Mac environment

Reviewers: sdong, anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54333
2016-02-17 23:32:14 -08:00
Islam AbdelRahman
df9ba6df62 Introduce SstFileManager::SetMaxAllowedSpaceUsage() to cap disk space usage
Summary:
Introude SstFileManager::SetMaxAllowedSpaceUsage() that can be used to limit the maximum space usage allowed for RocksDB.
When this limit is exceeded WriteImpl() will fail and return Status::Aborted()

Test Plan: unit testing

Reviewers: yhchiang, anthony, andrewkr, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D53763
2016-02-17 15:20:23 -08:00
Andrew Kryczka
3943d16780 Fix race conditions in auto-rolling logger
Summary:
For GetLogFileSize() and Flush(), they previously did not follow the
synchronization pattern for accessing logger_. This meant ResetLogger() could
cause logger_ destruction while the unsynchronized functions were accessing it,
causing a segfault.

Also made the mutex instance variable mutable so we can preserve
GetLogFileSize()'s const-ness.

Test Plan:
new test case, it's quite ugly because both threads need to access
one of the functions with SyncPoints (PosixLogger::Flush()), and also special
handling is needed to prevent the mutex and sync points from conflicting.

Reviewers: kradhakrishnan, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54237
2016-02-17 12:06:45 -08:00
fengjian
1336052497 fix ios build error 2016-02-17 20:22:40 +08:00
John Dennison
bd5f842bba fixes typo in options logging 2016-02-15 23:55:29 +00:00
Andrew Kryczka
1c868d6848 Fix includes for env_test
Summary:
Previously compilation failed when ROCKSDB_NO_FBCODE=1 because fcntl.h
wasn't included for open().

Related issue: https://github.com/facebook/rocksdb/issues/977

Test Plan:
verified below command works now:

  $ make clean && ROCKSDB_NO_FBCODE=1 ROCKSDB_DISABLE_FALLOCATE=1 make -j32 env_test

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54135
2016-02-12 14:17:14 -08:00
Yueh-Hsuan Chiang
908100399c Fixed a dependency issue of ThreadLocalPtr
Summary:
When a child thread that uses ThreadLocalPtr, ThreadLocalPtr::OnThreadExit
will be called when that child thread is destroyed.  However,
OnThreadExit will try to access a static singleton of ThreadLocalPtr,
which will be destroyed when the main thread exit.  As a result,
when a child thread that uses ThreadLocalPtr exits AFTER the main thread
exits, illegal memory access will occur.

This diff includes a test that reproduce this legacy bug.

    ==2095206==ERROR: AddressSanitizer: heap-use-after-free on address
    0x608000007fa0 at pc 0x959b79 bp 0x7f5fa7426b60 sp 0x7f5fa7426b58
    READ of size 8 at 0x608000007fa0 thread T1

This patch fix this issue by having the thread local mutex never be deleted
(but will leak small piece of memory at the end.)   The patch also describe
a better solution (thread_local) in the comment that requires gcc 4.8.1 and
in latest clang as a future work once we agree to move toward gcc 4.8.

Test Plan:
COMPILE_WITH_ASAN=1 make thread_local_test -j32
./thread_local_test --gtest_filter="*MainThreadDiesFirst"

Reviewers: anthony, hermanlee4, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D53013
2016-02-10 16:56:01 -08:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Andrew Kryczka
59b3ee658f Env function for bulk metadata retrieval
Summary:
Added this new function, which returns filename, size, and modified
timestamp for each file in the provided directory. The default implementation
retrieves the metadata sequentially using existing functions. In the next diff
I'll make HdfsEnv override this function to use libhdfs's bulk get function.

This won't work on windows due to the path separator.

Test Plan:
new unit test

  $ ./env_test --gtest_filter=EnvPosixTest.ConsistentChildrenMetadata

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: IslamAbdelRahman, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D53781
2016-02-09 14:54:32 -08:00
Islam AbdelRahman
8e6172bc57 Add BlockBasedTableOptions::index_block_restart_interval
Summary: Add a new option to BlockBasedTableOptions that will allow us to change the restart interval for the index block

Test Plan: unit tests

Reviewers: yhchiang, anthony, andrewkr, sdong

Reviewed By: sdong

Subscribers: march, dhruba

Differential Revision: https://reviews.facebook.net/D53721
2016-02-05 10:22:37 -08:00
sdong
f7c0f4e3ef perf_context.cc and iostats_context.cc use different output macro (fix unity build)
Summary: Unity build because perf_context.cc and iostats_context.cc define a different OUTPUT macro. Fix it.

Test Plan: Build unity

Reviewers: kradhakrishnan, anthony, yhchiang, andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: divchenko, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53769
2016-02-03 17:27:08 -08:00
Dmytro Ivchenko
aa5e3b7c04 PerfContext::ToString() add option to exclude zero counters
Test Plan: Added unit test to check w/ w/o zeros scenarios

Reviewers: yhchiang

Reviewed By: yhchiang

Subscribers: sdong, dhruba

Differential Revision: https://reviews.facebook.net/D52809
2016-02-01 13:41:13 -08:00
Venkatesh Radhakrishnan
3b2a1ddd2e Add options.base_background_compactions as a number of compaction threads for low compaction debt
Summary:
If options.base_background_compactions is given, we try to schedule number of compactions not existing this number, only when L0 files increase to certain number, or pending compaction bytes more than certain threshold, we schedule compactions based on options.max_background_compactions.

The watermarks are calculated based on slowdown thresholds.

Test Plan:
Add new test cases in column_family_test.
Adding more unit tests.

Reviewers: IslamAbdelRahman, yhchiang, kradhakrishnan, rven, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba, yoshinorim

Differential Revision: https://reviews.facebook.net/D53409
2016-01-29 16:15:53 -08:00
Islam AbdelRahman
d6c838f1e1 Add SstFileManager (component tracking all SST file in DBs and control the deletion rate)
Summary:
Add a new class SstFileTracker that will be notified whenever a DB add/delete/move and sst file, it will also replace DeleteScheduler
SstFileTracker can be used later to abort writes when we exceed a specific size

Test Plan: unit tests

Reviewers: rven, anthony, yhchiang, sdong

Reviewed By: sdong

Subscribers: igor, lovro, march, dhruba

Differential Revision: https://reviews.facebook.net/D50469
2016-01-28 18:35:01 -08:00
sdong
d20915d52a Disable stats about mutex duration by default
Summary: Measuring mutex duration will measure time inside DB mutex, which breaks our best practice. Add a stat level in Statistics class. By default, disable to measure the mutex operations.

Test Plan: Add a unit test to make sure it is off by default.

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

Reviewed By: yhchiang

Subscribers: MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53367
2016-01-26 14:56:55 -08:00
Andrew Kryczka
167bd8856d [directory includes cleanup] Finish removing util->db dependencies 2016-01-26 10:49:24 -08:00
Andrew Kryczka
acd7d58695 [directory includes cleanup] Remove util->db dependency for ThreadStatusUtil
Summary:
We can avoid the dependency by forward-declaring ColumnFamilyData and
then treating it as a black box. That means callers of ThreadStatusUtil need to
explicitly provide more options, even if they can be derived from the
ColumnFamilyData, since ThreadStatusUtil doesn't include the definition.

This is part of a series of diffs to eliminate circular dependencies between
directories (e.g., db/* files depending on util/* files and vice-versa).

Test Plan:
  $ ./db_test --gtest_filter=DBTest.GetThreadStatus
  $ make -j32 commit-prereq

Reviewers: sdong, yhchiang, IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D53361
2016-01-26 10:49:16 -08:00
Andrew Kryczka
46f9cd46af [directory includes cleanup] Move cross-function test points
Summary:
I split the db-specific test points out into a separate file under db/
directory. There were also a few bugs to fix in xfunc.{h,cc} that prevented it
from compiling previously; see https://reviews.facebook.net/D36825.

Test Plan:
compilation works now, below command works, will also run "make xfunc".

  $ make check ROCKSDB_XFUNC_TEST='managed_new' tests-regexp='DBTest' -j32

Reviewers: sdong, yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D53343
2016-01-26 10:49:05 -08:00
sdong
fb9811ee9b Add a perf context level that doesn't measure time for mutex operations
Summary: Timing mutex operations can impact scalability of the system. Add a new perf context level that can measure time counters except for mutex.

Test Plan: Add a new unit test case to make sure it is not set.

Reviewers: IslamAbdelRahman, rven, kradhakrishnan, yhchiang, anthony

Reviewed By: anthony

Subscribers: MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53199
2016-01-25 14:45:03 -08:00
sdong
f1ed170105 Add tests to make sure new DB or ColumnFamily options are settable through string
Summary: Add a test to fail if someone adds a DB options.

Test Plan: Run the test, run the test with valgrind. Add an option to DB option in the middle or in the end and make sure it fails.

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

Reviewed By: andrewkr

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53097
2016-01-22 16:18:44 -08:00
sdong
2c2b72218d Disable OptionsParserTest.BlockBasedTableOptionsAllFieldsSettable under CLANG
Summary: OptionsParserTest.BlockBasedTableOptionsAllFieldsSettable is failiong under CLANG. Disable the test to unblock the build.

Test Plan: Run it both of CLANG and GCC

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

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53157
2016-01-21 10:56:34 -08:00
sdong
202be23e46 Add test that verifies all options in BlockBasedTableOptions is settable through GetBlockBasedTableOptionsFromString()
Summary: Add a test OptionsParserTest.BlockBasedTableOptionsAdded, which will fail if a new option is added to BlockBasedTableOptions but is not settable through GetBlockBasedTableOptionsFromString().

Test Plan: Run the test. Also manually remove and add options and make sure it fails.

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

Reviewed By: andrewkr

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52953
2016-01-20 21:59:28 -08:00
sdong
fdbff42391 Crash test to make kill decision for every kill point
Summary:
In crash test, when coming to each kill point, we start a random class using seed as current second. With this approach, for every second, the random number used is the same. However, in each second, there are multiple kill points with different frequency. It makes it hard to reason about chance of kill point to trigger. With this commit, we use thread local random seed to generate the random number, so that it will take different values per second, hoping it makes chances of killing much easier to reason about.

Also significantly reduce the kill odd to make sure time before kiling is similar as before.

Test Plan: Run white box crash test and see the killing happens as expected and the run time time before killing reasonable.

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

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52971
2016-01-19 18:11:24 -08:00
David Bernard
df7c2f3b59 As per google coding standard replace "using" in option_builder.cc and
geodb_impl.cc
2016-01-20 00:27:29 +00:00
David Bernard
d78c6b28c4 Changes for build on solaris
Makefile adjust paths for solaris build
Makefile enable _GLIBCXX_USE_C99 so that std::to_string is available
db_compaction_test.cc Initialise a variable to avoid a compilation error
db_impl.cc Include <alloca.h>
db_test.cc Include <alloca.h>
Environment.java recognise solaris envrionment
options_bulder.cc Make log unambiguous
geodb_impl.cc Make log and floor unambiguous
2016-01-19 04:45:21 +00:00
Gunnar Kudrjavets
aec10f734b Guard falloc.h inclusion to avoid build breaks
Summary: Depending on the order of include paths and versions of various headers we may end up in a situation where we'll encounter a build break caused by redefinition of constants. gcc-4.9-glibc-2.20 header update to include/bits/fcntl-linux.h introduced the definitions of FALLOC_FL_* constants. However, linux/falloc.h from kernel-headers also has FALLOC_FL_* constants defined. Therefore during the compilation we'll get "previously defined" errors.

Test Plan:
Both in the environment where the build break manifests (to make sure that the change fixed the problem) and in the environment where everything builds fine (to make sure that there are no regressions):

make clean
make -j 32

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D52821
2016-01-14 22:47:15 -08:00
Dmitri Smirnov
ac50fd3a71 Align statistics
Use Yield macro to make it a little more portable between platforms.
2016-01-13 14:53:23 -08:00
Igor Canadi
48a8667c30 Merge pull request #929 from warrenfalk/fix32
fix a compile error on 32-bit (fixes #634)
2016-01-12 11:02:36 -08:00
sdong
9a8e3f73ed plain table reader: non-mmap mode to keep two recent buffers
Summary: In plain table reader's non-mmap mode, we only keep the most recent read buffer. However, for binary search, it is likely we come back to a location to read. To avoid one pread in such a case, we keep two read buffers. It should cover most of the cases.

Test Plan:
1. run tests
2. check the optimization works through strace when running
./table_reader_bench -mmap_read=false --num_keys2=1 -num_keys1=5000 -table_factory=plain_table --iterator --through_db

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

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51171
2016-01-08 10:53:57 -08:00
Warren Falk
94d9df2482 fix an unused function compiler warning in crc32c in 32-bit mode 2016-01-07 13:27:20 -05:00
Warren Falk
2f01e10fa9 use static_cast in crc32c instead of c-style cast 2016-01-07 13:22:09 -05:00
Warren Falk
601f1306a1 fix shorten-64-to-32 warning in crc32c 2016-01-07 13:12:15 -05:00
Warren Falk
55b37efa15 fix a compile error on 32-bit 2016-01-07 11:51:52 -05:00
sdong
c9e2490bc6 Fix DynamicBloomTest.concurrent_with_perf to pass TSAN
Summary: TSAN fails on DynamicBloomTest.concurrent_with_perf. This change fixes it. Not sure why though.

Test Plan: Run the test with TSAN and make sure no warning shown.

Reviewers: yhchiang, IslamAbdelRahman, anthony, ngbronson, rven

Reviewed By: rven

Subscribers: rven, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52383
2015-12-29 16:28:45 -08:00
sdong
edf1cd497f Not generating "__attribute__((__unused__))" for padding fields if it is not CLANG
Summary: Adding "__attribute__((__unused__))" after padding fields will pass CLANG build but will fail gcc 4.8.1. Fix it by not generating it under GCC 4.8.1.

Test Plan: Build under four combinations of USE_CLANG=0,1 and ROCKSDB_FBCODE_BUILD_WITH_481=0.1.

Reviewers: yhchiang, rven, ngbronson, anthony, IslamAbdelRahman

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52371
2015-12-28 18:37:23 -08:00
sdong
11672df19a Fix CLANG errors introduced by 7d87f02799
Summary: Fix some CLANG errors introduced in 7d87f02799

Test Plan: Build with both of CLANG and gcc

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

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52329
2015-12-28 10:00:58 -08:00
Siying Dong
7fafd52dce Merge pull request #900 from shuzhang1989/hdfs_env_fix
add a factory method for creating hdfs env
2015-12-28 09:28:04 -08:00
Shu Zhang
2b7c810db8 more foramt 2015-12-26 19:52:35 -08:00
Shu Zhang
b79ccbd573 indent 2015-12-26 19:50:28 -08:00
Nathan Bronson
7d87f02799 support for concurrent adds to memtable
Summary:
This diff adds support for concurrent adds to the skiplist memtable
implementations.  Memory allocation is made thread-safe by the addition of
a spinlock, with small per-core buffers to avoid contention.  Concurrent
memtable writes are made via an additional method and don't impose a
performance overhead on the non-concurrent case, so parallelism can be
selected on a per-batch basis.

Write thread synchronization is an increasing bottleneck for higher levels
of concurrency, so this diff adds --enable_write_thread_adaptive_yield
(default off).  This feature causes threads joining a write batch
group to spin for a short time (default 100 usec) using sched_yield,
rather than going to sleep on a mutex.  If the timing of the yield calls
indicates that another thread has actually run during the yield then
spinning is avoided.  This option improves performance for concurrent
situations even without parallel adds, although it has the potential to
increase CPU usage (and the heuristic adaptation is not yet mature).

Parallel writes are not currently compatible with
inplace updates, update callbacks, or delete filtering.
Enable it with --allow_concurrent_memtable_write (and
--enable_write_thread_adaptive_yield).  Parallel memtable writes
are performance neutral when there is no actual parallelism, and in
my experiments (SSD server-class Linux and varying contention and key
sizes for fillrandom) they are always a performance win when there is
more than one thread.

Statistics are updated earlier in the write path, dropping the number
of DB mutex acquisitions from 2 to 1 for almost all cases.

This diff was motivated and inspired by Yahoo's cLSM work.  It is more
conservative than cLSM: RocksDB's write batch group leader role is
preserved (along with all of the existing flush and write throttling
logic) and concurrent writers are blocked until all memtable insertions
have completed and the sequence number has been advanced, to preserve
linearizability.

My test config is "db_bench -benchmarks=fillrandom -threads=$T
-batch_size=1 -memtablerep=skip_list -value_size=100 --num=1000000/$T
-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
--block_size=16384 --allow_concurrent_memtable_write" on a two-socket
Xeon E5-2660 @ 2.2Ghz with lots of memory and an SSD hard drive.  With 1
thread I get ~440Kops/sec.  Peak performance for 1 socket (numactl
-N1) is slightly more than 1Mops/sec, at 16 threads.  Peak performance
across both sockets happens at 30 threads, and is ~900Kops/sec, although
with fewer threads there is less performance loss when the system has
background work.

Test Plan:
1. concurrent stress tests for InlineSkipList and DynamicBloom
2. make clean; make check
3. make clean; DISABLE_JEMALLOC=1 make valgrind_check; valgrind db_bench
4. make clean; COMPILE_WITH_TSAN=1 make all check; db_bench
5. make clean; COMPILE_WITH_ASAN=1 make all check; db_bench
6. make clean; OPT=-DROCKSDB_LITE make check
7. verify no perf regressions when disabled

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: MarkCallaghan, IslamAbdelRahman, anthony, yhchiang, rven, sdong, guyg8, kradhakrishnan, dhruba

Differential Revision: https://reviews.facebook.net/D50589
2015-12-25 11:03:40 -08:00
Shu Zhang
b4aa823661 format 2015-12-24 20:38:35 -08:00
Shu Zhang
4dfdd1d928 format 2015-12-24 20:32:29 -08:00
Siying Dong
298ba27ae2 Merge pull request #846 from yuslepukhin/enble_c4244_lossofdata
Enable MS compiler warning c4244.
2015-12-23 22:59:42 -08:00
Siying Dong
7810aa802a Merge pull request #899 from zhipeng-jia/fix_clang_warning
Fix clang warnings
2015-12-23 22:58:52 -08:00
Zhipeng Jia
ec2664fefd Fix clang compile error under Linux 2015-12-24 12:41:40 +08:00
Shu Zhang
4fd23fb130 add a factory method for creating hdfs env 2015-12-23 17:26:50 -08:00
sdong
15b8902264 Change default options.delayed_write_rate
Summary: We now have a mechanism to further slowdown writes. Double default options.delayed_write_rate to try to keep the default behavior closer to it used to be.

Test Plan: Run all tests.

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: yhchiang, kradhakrishnan, rven, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52281
2015-12-23 14:51:55 -08:00
sdong
b9f77ba12b When slowdown is triggered, reduce the write rate
Summary: It's usually hard for users to set a value of options.delayed_write_rate. With this diff, after slowdown condition triggers, we greedily reduce write rate if estimated pending compaction bytes increase. If estimated compaction pending bytes drop, we increase the write rate.

Test Plan:
Add a unit test
Test with db_bench setting:
TEST_TMPDIR=/dev/shm/ ./db_bench --benchmarks=fillrandom -num=10000000 --soft_pending_compaction_bytes_limit=1000000000 --hard_pending_compaction_bytes_limit=3000000000 --delayed_write_rate=100000000

and make sure without the commit, write stop will happen, but with the commit, it will not happen.

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

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52131
2015-12-23 11:33:15 -08:00
Igor Canadi
8ac7fb8377 Merge pull request #863 from zhangyybuaa/fix_hdfs_error
Fix build error with hdfs
2015-12-22 09:27:51 +01:00
sdong
167fb919a5 ZSTD to use CompressionOptions.level
Summary: Now ZSTD hard code level 1. Change it to use the compression level setting.

Test Plan: Run it with hacked codes of sst_dump and show ZSTD compression sizes with different levels.

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

Reviewed By: IslamAbdelRahman

Subscribers: yoshinorim, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52041
2015-12-16 16:58:04 -08:00
Islam AbdelRahman
aececc209e Introduce ReadOptions::pin_data (support zero copy for keys)
Summary:
This patch update the Iterator API to introduce new functions that allow users to keep the Slices returned by key() valid as long as the Iterator is not deleted

ReadOptions::pin_data : If true keep loaded blocks in memory as long as the iterator is not deleted
Iterator::IsKeyPinned() : If true, this mean that the Slice returned by key() is valid as long as the iterator is not deleted

Also add a new option BlockBasedTableOptions::use_delta_encoding to allow users to disable delta_encoding if needed.

Benchmark results (using https://phabricator.fb.com/P20083553)

```
// $ du -h /home/tec/local/normal.4K.Snappy/db10077
// 6.1G    /home/tec/local/normal.4K.Snappy/db10077

// $ du -h /home/tec/local/zero.8K.LZ4/db10077
// 6.4G    /home/tec/local/zero.8K.LZ4/db10077

// Benchmarks for shard db10077
// _build/opt/rocks/benchmark/rocks_copy_benchmark \
//      --normal_db_path="/home/tec/local/normal.4K.Snappy/db10077" \
//      --zero_db_path="/home/tec/local/zero.8K.LZ4/db10077"

// First run
// ============================================================================
// rocks/benchmark/RocksCopyBenchmark.cpp          relative  time/iter  iters/s
// ============================================================================
// BM_StringCopy                                                 1.73s  576.97m
// BM_StringPiece                                   103.74%      1.67s  598.55m
// ============================================================================
// Match rate : 1000000 / 1000000

// Second run
// ============================================================================
// rocks/benchmark/RocksCopyBenchmark.cpp          relative  time/iter  iters/s
// ============================================================================
// BM_StringCopy                                              611.99ms     1.63
// BM_StringPiece                                   203.76%   300.35ms     3.33
// ============================================================================
// Match rate : 1000000 / 1000000
```

Test Plan: Unit tests

Reviewers: sdong, igor, anthony, yhchiang, rven

Reviewed By: rven

Subscribers: dhruba, lovro, adsharma

Differential Revision: https://reviews.facebook.net/D48999
2015-12-16 12:08:30 -08:00
Venkatesh Radhakrishnan
030215bf01 Running manual compactions in parallel with other automatic or manual compactions in restricted cases
Summary:
This diff provides a framework for doing manual
compactions in parallel with other compactions. We now have a deque of manual compactions. We also pass manual compactions as an argument from RunManualCompactions down to
BackgroundCompactions, so that RunManualCompactions can be reentrant.
Parallelism is controlled by the two routines
ConflictingManualCompaction to allow/disallow new parallel/manual
compactions based on already existing ManualCompactions. In this diff, by default manual compactions still have to run exclusive of other compactions. However, by setting the compaction option, exclusive_manual_compaction to false, it is possible to run other compactions in parallel with a manual compaction. However, we are still restricted to one manual compaction per column family at a time. All of these restrictions will be relaxed in future diffs.
I will be adding more tests later.

Test Plan: Rocksdb regression + new tests + valgrind

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

Reviewed By: sdong

Subscribers: yoshinorim, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D47973
2015-12-14 11:20:34 -08:00
Dmitri Smirnov
aca403d2b5 Fix another rebase problems. 2015-12-11 17:33:40 -08:00
Dmitri Smirnov
236fe21c92 Enable MS compiler warning c4244.
Mostly due to the fact that there are differences in sizes of int,long
  on 64 bit systems vs GNU.
2015-12-11 16:47:34 -08:00
Yueh-Hsuan Chiang
00d6edf6a0 Ensure the destruction order of PosixEnv and ThreadLocalPtr
Summary:
By default, RocksDB initializes the singletons of ThreadLocalPtr first, then initializes PosixEnv
via static initializer.  Destructor terminates objects in reverse order, so terminating PosixEnv
(calling pthread_mutex_lock), then ThreadLocal (calling pthread_mutex_destroy).

However, in certain case, application might initialize PosixEnv first, then ThreadLocalPtr.
This will cause core dump at the end of the program (eg. https://github.com/facebook/mysql-5.6/issues/122)

This patch fix this issue by ensuring the destruction order by moving the global static singletons
to function static singletons.  Since function static singletons are initialized when the function is first
called, this property allows us invoke to enforce the construction of the static PosixEnv and the
singletons of ThreadLocalPtr by calling the function where the ThreadLocalPtr singletons belongs
right before we initialize the static PosixEnv.

Test Plan: Verified in the MyRocks.

Reviewers: yoshinorim, IslamAbdelRahman, rven, kradhakrishnan, anthony, sdong, MarkCallaghan

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51789
2015-12-11 00:21:58 -08:00
charsyam
c30b499541 fix typos in comments 2015-12-11 01:54:48 +09:00
sdong
56e77f0967 Deprecate options.soft_rate_limit and add options.soft_pending_compaction_bytes_limit
Summary: Deprecate options.soft_rate_limit, which is hard to tune, with options.soft_pending_compaction_bytes_limit, which would trigger the slowdown if estimated pending compaction bytes exceeds the threshold. The hope is to make it more striaght-forward to tune.

Test Plan: Modify DBTest.SoftLimit to cover options.soft_pending_compaction_bytes_limit instead; run all unit tests.

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

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51117
2015-12-09 18:22:45 -08:00
sdong
d6e1035a1f A new compaction picking priority that optimizes for write amplification for random updates.
Summary: Introduce a compaction picking priority that picks files who contains the oldest rows to compact. This is a mode that slightly improves write amplification for random update cases.

Test Plan: Add a unit test and run it in valgrind too.

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

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51459
2015-12-09 18:13:03 -08:00
yuslepukhin
49957f9a98 Prefer integer arithmetics
The code had conversion to double then casting to size_t
  and then casting uint32_t which caused compiler warning (VS15).
2015-12-09 14:06:23 -08:00
Siying Dong
9c227923c6 Merge pull request #788 from OpenChannelSSD/to_fb_master2
Move posix threads into a library
2015-12-08 18:06:38 -08:00
Siying Dong
fa3dbf203f Merge pull request #853 from Vaisman/enable_C4267_warning
Enable C4267 warning
2015-12-08 17:59:24 -08:00
Siying Dong
56bbecc316 Merge pull request #867 from SherlockNoMad/CacheFix
Replace malloc with new for LRU Cache Handle
2015-12-08 17:58:29 -08:00
Yueh-Hsuan Chiang
774b80e99e Resubmit the fix for a race condition in persisting options
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
2015-12-08 17:01:02 -08:00
sdong
ea11923550 Upgrade to ZSTD 0.4.2
Summary: Change to call the new compression function.

Test Plan: build and run db_bench with the compression to make sure it compresses.

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

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51603
2015-12-08 16:33:26 -08:00
sdong
770dea9325 Fix occasional failure of DBTest.DynamicCompactionOptions
Summary: DBTest.DynamicCompactionOptions ocasionally fails during valgrind run. We sent a sleeping task to block compaction thread pool but we don't wait it to run.

Test Plan: Run the test multiple times in an environment which can cause failure.

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

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51687
2015-12-07 18:38:39 -08:00
sdong
f307036bde Revert "Fix a race condition in persisting options"
This reverts commit 2fa3ed5180. It breaks RocksDB lite build
2015-12-07 17:09:12 -08:00
Yueh-Hsuan Chiang
2fa3ed5180 Fix a race condition in persisting options
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
2015-12-07 15:25:12 -08:00
Javier González
b2863017b1 Move posix threads into a library
Summary: This patch moves all posix thread logic to a separate library.
The motivation is to allow another environments to easily reuse posix
threads. HDFS wraps already posix threads; this split would simplify
this code.

Test Plan: No new functionality is added to posix Env or the threading
library, thus the current tests should suffice.
2015-12-07 12:03:38 +01:00
SherlockNoMad
3a98a7ae7f Replace malloc with new for LRU Cache Handle 2015-12-04 15:12:07 -08:00
Zhang Yangyang
4687ced5db fix ToString() not declared error 2015-12-02 21:45:28 +08:00
sdong
d27ea4c9e5 Initialize options.row_cache
Summary: options.row_cache should already been initialized as null by default. Still try to set it following current convention, because one valgrind failure reports a failure related to it.

Test Plan: Run all unit tests

Reviewers: yhchiang, kradhakrishnan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51303
2015-11-30 10:30:35 -08:00
Nathan Bronson
9a9d4759b2 InlineSkipList part 3/3 - new skiplist type that colocates key and node
Summary:
This diff completes the creation of InlineSkipList<Cmp>, which is like
SkipList<const char*, Cmp> but it always allocates the key contiguously
with the node.  This allows us to remove the pointer from the node
to the key.  As a result the memory usage of the skip list is reduced
(by 1 to sizeof(void*) bytes depending on the padding required to align
the key storage), cache locality is improved, and we halve the number
of calls to the allocator.

For skip lists whose keys are freshly-allocated const char*,
InlineSkipList is stricly preferrable to SkipList.  This diff doesn't
replace SkipList, however, because some of the use cases of SkipList in
RocksDB are either character sequences that are not allocated at the
same time as the skip list node allocation (for example
hash_linklist_rep) or have different key types (for example
write_batch_with_index).  Taking advantage of inline allocation for
those cases is left to future work.

The perf win is biggest for small values.  For single-threaded CPU-bound
(32M fillrandom operations with no WAL log) with 16 byte keys and 0 byte
values, the db_bench perf goes from ~310k ops/sec to ~410k ops/sec.  For
large values the improvement is less pronounced, but seems to be between
5% and 10% on the same configuration.

Test Plan: make check

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D51123
2015-11-24 15:16:02 -08:00
Vasili Svirski
41b32c6059 Enable C4267 warning
* conversion from 'size_t' to 'type', by add static_cast

Tested:
* by build solution on Windows, Linux locally,
* run tests
* build CI system successful
2015-11-24 16:33:09 +03:00
yuslepukhin
047bd22aae Build on Visual Studio 2015 Update 1 2015-11-20 15:31:47 -08:00
Dmitri Smirnov
89bacb7e7d Enable MS Warning C4804 : unsafe use of type 'bool' in operation 2015-11-18 16:23:19 -08:00
Islam AbdelRahman
4159ab8169 Merge pull request #839 from SherlockNoMad/memtableOption
Support Memtable Factory Parse in option_helper.cc
2015-11-17 17:09:49 -08:00
sdong
6170fec251 Fix build broken by previous commit of "option helper refactor"
Summary:
The commit of option helper refactor broken the build:
(1) a git merge problem
(2) some uncaught compiler warning
Fix it.

Test Plan: Make sure "make all" passes

Reviewers: anthony, IslamAbdelRahman, rven, kradhakrishnan, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D50943
2015-11-17 16:52:54 -08:00
Siying Dong
3a6643c2fd Merge pull request #805 from SherlockNoMad/OptionHelperFix
Option Helper Refactoring
2015-11-17 16:24:52 -08:00
SherlockNoMad
bd7be035e0 Support Memtable Factory Parse in option_helper.cc 2015-11-17 14:29:01 -08:00
Islam AbdelRahman
a163cc2d5a Lint everything
Summary:
```
arc2 lint --everything
```

run the linter on the whole code repo to fix exisitng lint issues

Test Plan: make check -j64

Reviewers: sdong, rven, anthony, kradhakrishnan, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50769
2015-11-16 12:56:21 -08:00
Yueh-Hsuan Chiang
e11f676e34 Add OptionsUtil::LoadOptionsFromFile() API
Summary:
This patch adds OptionsUtil::LoadOptionsFromFile() and
OptionsUtil::LoadLatestOptionsFromDB(), which allow developers
to construct DBOptions and ColumnFamilyOptions from a RocksDB
options file.  Note that most pointer-typed options such as
merge_operator will not be constructed.

With this API, developers no longer need to remember all the
options in order to reopen an existing rocksdb instance like
the following:

  DBOptions db_options;
  std::vector<std::string> cf_names;
  std::vector<ColumnFamilyOptions> cf_opts;

  // Load primitive-typed options from an existing DB
  OptionsUtil::LoadLatestOptionsFromDB(
      dbname, &db_options, &cf_names, &cf_opts);

  // Initialize necessary pointer-typed options
  cf_opts[0].merge_operator.reset(new MyMergeOperator());
  ...

  // Construct the vector of ColumnFamilyDescriptor
  std::vector<ColumnFamilyDescriptor> cf_descs;
  for (size_t i = 0; i < cf_opts.size(); ++i) {
    cf_descs.emplace_back(cf_names[i], cf_opts[i]);
  }

  // Open the DB
  DB* db = nullptr;
  std::vector<ColumnFamilyHandle*> cf_handles;
  auto s = DB::Open(db_options, dbname, cf_descs,
                    &handles, &db);

Test Plan:
Augment existing tests in column_family_test
options_test
db_test

Reviewers: igor, IslamAbdelRahman, sdong, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49095
2015-11-12 06:52:43 -08:00
Yueh-Hsuan Chiang
e114f0abb8 Enable RocksDB to persist Options file.
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
2015-11-10 22:58:01 -08:00
Dmitri Smirnov
5270b33bd3 Make use of portable uint64_t type to make possible file access
in 64-bit.

  Currently, a signed off_t type is being used for the following
  interfaces for both offset and the length in bytes:
  * `Allocate`
  * `RangeSync`

  On Linux `off_t` is automatically either 32 or 64-bit depending on
  the platform. On Windows it is always a 32-bit signed long which
  limits file access and in particular space pre-allocation
  to effectively 2 Gb.

  Proposal is to replace off_t with uint64_t as a portable type
  always access files with 64-bit interfaces.

  May need to modify posix code but lack resources to test it.
2015-11-10 17:03:42 -08:00
Nathan Bronson
505accda38 remove constexpr from util/random.h for MSVC compat
Summary:
Scoped anonymous enums seem to be better supported than static
constexpr at the moment, so this diff replaces the latter with the former.
Also, this diff removes an incorrect inclusion of pthread.h.  MSVC build
was broken starting with D50439.

Test Plan:
1. build
2. observe proper skiplist behavior by absence of pathological slowdown
3. push diff to tmp_try_windows branch to tickle AppVeyor
4. wait for contbuild before committing to master

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D50517
2015-11-10 16:41:23 -08:00
Nathan Bronson
b81b430987 Switch to thread-local random for skiplist
Summary:
Using a TLS random instance for skiplist makes it smaller
(useful for hash_skiplist_rep) and prepares skiplist for concurrent
adds.  This diff also modifies the branching factor math to avoid an
unnecessary division.

This diff has the effect of changing the sequence of skip list node
height choices made by tests, so it has the potential to cause unit
test failures for tests that implicitly rely on the exact structure
of the skip list.  Tests that try to exactly trigger a compaction are
likely suspects for this problem (these tests have always been brittle to
changes in the skiplist details).  I've minimizes this risk by reseeding
the main thread's Random at the beginning of each test, increasing the
universal compaction size_ratio limit from 101% to 105% for some tests,
and verifying that the tests pass many times.

Test Plan: for i in `seq 0 9`; do make check; done

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D50439
2015-11-09 19:25:22 -08:00
Dmitri Smirnov
20f57b1715 Enable Windows warnings C4307 C4309 C4512 C4701
Enable C4307 'operator' : integral constant overflow
  Longs and ints on Windows are 32-bit hence the overflow
  Enable C4309 'conversion' : truncation of constant value
  Enable C4512 'class' : assignment operator could not be generated
  Enable C4701 Potentially uninitialized local variable 'name' used
2015-11-06 11:34:06 -08:00
Venkatesh Radhakrishnan
9d50afc3b9 Prefix-based iterating only shows keys in prefix
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
2015-11-05 13:24:05 -08:00