Summary:
Make kPageSize extern const size_t (used in draft https://github.com/facebook/rocksdb/issues/6427)
Make kLitteEndian constexpr bool
Clarify a couple of comments
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6443
Test Plan: make check, CI
Differential Revision: D20044558
Pulled By: pdillinger
fbshipit-source-id: e0c5cc13229c82726280dc0ddcba4078346b8418
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
A new interface method Env::GetFreeSpace was added in https://github.com/facebook/rocksdb/issues/4164. It needs to be implemented for Windows port. Some error_handler_test cases fail on Windows because recovery cannot succeed without free space being reported.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6265
Differential Revision: D19303065
fbshipit-source-id: 1f1a83e53f334284781cf61feabc996e87b945ca
Summary:
From the reset of the code, it looks this this maybe can be unconditionally given the attribute? But I couldn't test with MSVC so I defensively put under CPP.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6075
Differential Revision: D18723749
fbshipit-source-id: 45fc8732c28dd29aab1644225d68f3c6f39bd69b
Summary:
Since we do not evict a file's blocks from block cache before that file
is deleted, we require a file's cache ID prefix is both unique and
non-reusable. However, the Windows functionality we were relying on only
guaranteed uniqueness. That meant a newly created file could be assigned
the same cache ID prefix as a deleted file. If the newly created file
had block offsets matching the deleted file, full cache keys could be
exactly the same, resulting in obsolete data blocks returned from cache
when trying to read from the new file.
We noticed this when running on FAT32 where compaction was writing out
of order keys due to reading obsolete blocks from its input files. The
functionality is documented as behaving the same on NTFS, although I
wasn't able to repro it there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5844
Test Plan:
we had a reliable repro of out-of-order keys on FAT32 that
was fixed by this change
Differential Revision: D17752442
fbshipit-source-id: 95d983f9196cf415f269e19293b97341edbf7e00
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830
Test Plan: Run all existing tests.
Differential Revision: D17488031
fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
Summary:
Refactoring to consolidate implementation details of legacy
Bloom filters. This helps to organize and document some related,
obscure code.
Also added make/cpp var TEST_CACHE_LINE_SIZE so that it's easy to
compile and run unit tests for non-native cache line size. (Fixed a
related test failure in db_properties_test.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5784
Test Plan:
make check, including Recently added Bloom schema unit tests
(in ./plain_table_db_test && ./bloom_test), and including with
TEST_CACHE_LINE_SIZE=128U and TEST_CACHE_LINE_SIZE=256U. Tested the
schema tests with temporary fault injection into new implementations.
Some performance testing with modified unit tests suggest a small to moderate
improvement in speed.
Differential Revision: D17381384
Pulled By: pdillinger
fbshipit-source-id: ee42586da996798910fc45ac0b6289147f16d8df
Summary:
For our default block cache, each additional entry has extra memory overhead. It include LRUHandle (72 bytes currently) and the cache key (two varint64, file id and offset). The usage is not negligible. For example for block_size=4k, the overhead accounts for an extra 2% memory usage for the cache. The patch charging the cache for the extra usage, reducing untracked memory usage outside block cache. The feature is enabled by default and can be disabled by passing kDontChargeCacheMetadata to the cache constructor.
This PR builds up on https://github.com/facebook/rocksdb/issues/4258
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5797
Test Plan:
- Existing tests are updated to either disable the feature when the test has too much dependency on the old way of accounting the usage or increasing the cache capacity to account for the additional charge of metadata.
- The Usage tests in cache_test.cc are augmented to test the cache usage under kFullChargeCacheMetadata.
Differential Revision: D17396833
Pulled By: maysamyabandeh
fbshipit-source-id: 7684ccb9f8a40ca595e4f5efcdb03623afea0c6f
Summary:
This will allow us to fix history by having the code changes for PR#5784 properly attributed to it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5810
Differential Revision: D17400231
Pulled By: pdillinger
fbshipit-source-id: 2da8b1cdf2533cfedb35b5526eadefb38c291f09
Summary:
Use delete to disable automatic generated methods instead of private, and put the constructor together for more clear.This modification cause the unused field warning, so add unused attribute to disable this warning.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5009
Differential Revision: D17288733
fbshipit-source-id: 8a767ce096f185f1db01bd28fc88fef1cdd921f3
Summary:
Previously, if the jemalloc was built with nonempty string for
`--with-jemalloc-prefix`, then `HasJemalloc()` would return false on
Linux, so jemalloc would not be used at runtime. On Mac, it would cause
a linker failure due to no definitions found for the weak functions
declared in "port/jemalloc_helper.h". This should be a rare problem
because (1) on Linux the default `--with-jemalloc-prefix` value is the
empty string, and (2) Homebrew's build explicitly sets
`--with-jemalloc-prefix` to the empty string.
However, there are cases where `--with-jemalloc-prefix` is nonempty.
For example, when building jemalloc from source on Mac, the default
setting is `--with-jemalloc-prefix=je_`. Such jemalloc builds should be
usable by RocksDB.
The fix is simple. Defining `JEMALLOC_MANGLE` before including
"jemalloc.h" causes it to define unprefixed symbols that are aliases for
each of the prefixed symbols. Thanks to benesch for figuring this out
and explaining it to me.
Fixes https://github.com/facebook/rocksdb/issues/1462.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5521
Test Plan:
build jemalloc with prefixed symbols:
```
$ ./configure --with-jemalloc-prefix=lol
$ make
```
compile rocksdb against it:
```
$ WITH_JEMALLOC_FLAG=1 JEMALLOC=1 EXTRA_LDFLAGS="-L/home/andrew/jemalloc/lib/" EXTRA_CXXFLAGS="-I/home/andrew/jemalloc/include/" make -j12 ./db_bench
```
run db_bench and verify jemalloc actually used:
```
$ ./db_bench -benchmarks=fillrandom -statistics=true -dump_malloc_stats=true -stats_dump_period_sec=1
$ grep jemalloc /tmp/rocksdbtest-1000/dbbench/LOG
2019/06/29-12:20:52.088658 7fc5fb7f6700 [_impl/db_impl.cc:837] ___ Begin jemalloc statistics ___
...
```
Differential Revision: D16092758
fbshipit-source-id: c2c358346190ed62ceb2a3547a6c4c180b12f7c4
Summary:
"__attribute__((__weak__))" was introduced in port\jemalloc_helper.h. It's not supported by Microsoft VS 2015, resulting in compile error. This fix adds a #if branch to work around the compile issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5458
Differential Revision: D15827285
fbshipit-source-id: 8c5f7ad31de1ac677bd96f16c4450767de834beb
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387
Differential Revision: D15579036
Pulled By: siying
fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377
Differential Revision: D15551366
Pulled By: siying
fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
Summary:
Remove PATENTS related wording from a few stragglers which still reference the old PATENTS file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5326
Differential Revision: D15423297
Pulled By: sagar0
fbshipit-source-id: 4babcddfc120b7d2fed6eb3898287cf8012bf8ea
Summary:
The existing implementation does not guarantee bytes reach disk every `bytes_per_sync` when writing SST files, or every `wal_bytes_per_sync` when writing WALs. This can cause confusing behavior for users who enable this feature to avoid large syncs during flush and compaction, but then end up hitting them anyways.
My understanding of the existing behavior is we used `sync_file_range` with `SYNC_FILE_RANGE_WRITE` to submit ranges for async writeback, such that we could continue processing the next range of bytes while that I/O is happening. I believe we can preserve that benefit while also limiting how far the processing can get ahead of the I/O, which prevents huge syncs from happening when the file finishes.
Consider this `sync_file_range` usage: `sync_file_range(fd_, 0, static_cast<off_t>(offset + nbytes), SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE)`. Expanding the range to start at 0 and adding the `SYNC_FILE_RANGE_WAIT_BEFORE` flag causes any pending writeback (like from a previous call to `sync_file_range`) to finish before it proceeds to submit the latest `nbytes` for writeback. The latest `nbytes` are still written back asynchronously, unless processing exceeds I/O speed, in which case the following `sync_file_range` will need to wait on it.
There is a second change in this PR to use `fdatasync` when `sync_file_range` is unavailable (determined statically) or has some known problem with the underlying filesystem (determined dynamically).
The above two changes only apply when the user enables a new option, `strict_bytes_per_sync`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5183
Differential Revision: D14953553
Pulled By: siying
fbshipit-source-id: 445c3862e019fb7b470f9c7f314fc231b62706e9
Summary:
mv port/dirent.h to port/port_dirent.h to avoid compile err when use port dir as header dir output
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5152
Differential Revision: D14779409
Pulled By: siying
fbshipit-source-id: d4162c47c979c6e8cc6a9e601802864ab3768ecb
Summary:
This PR allows RocksDB to run in single-primary, multi-secondary process mode.
The writer is a regular RocksDB (e.g. an `DBImpl`) instance playing the role of a primary.
Multiple `DBImplSecondary` processes (secondaries) share the same set of SST files, MANIFEST, WAL files with the primary. Secondaries tail the MANIFEST of the primary and apply updates to their own in-memory state of the file system, e.g. `VersionStorageInfo`.
This PR has several components:
1. (Originally in #4745). Add a `PathNotFound` subcode to `IOError` to denote the failure when a secondary tries to open a file which has been deleted by the primary.
2. (Similar to #4602). Add `FragmentBufferedReader` to handle partially-read, trailing record at the end of a log from where future read can continue.
3. (Originally in #4710 and #4820). Add implementation of the secondary, i.e. `DBImplSecondary`.
3.1 Tail the primary's MANIFEST during recovery.
3.2 Tail the primary's MANIFEST during normal processing by calling `ReadAndApply`.
3.3 Tailing WAL will be in a future PR.
4. Add an example in 'examples/multi_processes_example.cc' to demonstrate the usage of secondary RocksDB instance in a multi-process setting. Instructions to run the example can be found at the beginning of the source code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4899
Differential Revision: D14510945
Pulled By: riversand963
fbshipit-source-id: 4ac1c5693e6012ad23f7b4b42d3c374fecbe8886
Summary:
The original implementation of WinEnvIO::NowNanos() has a constant data overflow by:
li.QuadPart *= std::nano::den;
As a result, the api provides a incorrect result.
e.g.:
li.QuadPart=13477844301545
std::nano::den=1e9
The fix uses pre-computed nano_seconds_per_period_ to present the nano seconds per performance counter period, in the case if nano::den is divisible by perf_counter_frequency_. Otherwise it falls back to use high_resolution_clock.
siying ajkr
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5062
Differential Revision: D14426842
Pulled By: anand1976
fbshipit-source-id: 127f1daf423dd4b30edd0dcf8ea0466f468bec12
Summary:
The patch adds a new config option to LRUCacheOptions that enables
users to choose whether to use an adaptive mutex for the LRU block
cache (on platforms where adaptive mutexes are supported). The default
is true if RocksDB is compiled with -DROCKSDB_DEFAULT_TO_ADAPTIVE_MUTEX,
false otherwise.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5054
Differential Revision: D14542749
Pulled By: ltamasi
fbshipit-source-id: 0065715ab6cf91f10444b737fed8c8aee6a8a0d2
Summary:
JEMALLOC_CXX_THROW is not defined for earlier versions of jemalloc (e.g. 3.6), causing builds to fail on some platforms. Fixing it. Closes#4869
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5053
Differential Revision: D14390034
Pulled By: sagar0
fbshipit-source-id: b2b7a03cd377201ef385eb521f65bae85c558055
Summary:
Declare Jemalloc non-standard APIs as weak symbols, so that if Jemalloc is linked with the binary, these symbols will be replaced by Jemalloc's, otherwise they will be nullptr. This is similar to how folly detect jemalloc, but we assume the main program use jemalloc as long as jemalloc is linked: https://github.com/facebook/folly/blob/master/folly/memory/Malloc.h#L147
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4844
Differential Revision: D13574934
Pulled By: yiwu-arbug
fbshipit-source-id: 7ea871beb1be7d5a1259cc38f9b78078793db2db
Summary:
Ran the following commands to recursively change all the files under RocksDB:
```
find . -type f -name "*.cc" -exec sed -i 's/ unique_ptr/ std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<unique_ptr/<std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/ shared_ptr/ std::shared_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<shared_ptr/<std::shared_ptr/g' {} +
```
Running `make format` updated some formatting on the files touched.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4638
Differential Revision: D12934992
Pulled By: sagar0
fbshipit-source-id: 45a15d23c230cdd64c08f9c0243e5183934338a8
Summary:
The default behaviour of rocksdb is to use the `*A(` windows API functions.
These accept filenames in the currently configured system encoding,
be it Latin 1, utf8 or whatever.
If the Application intends to completely work with utf8 strings internally,
converting these to that codepage properly isn't even always possible.
Thus this patch adds a switch to use the `*W(` functions, which accept
UTF-16 filenames, and uses C++11 features to translate the
UTF8 containing std::string to an UTF16 containing std::wstring.
This feature is a compile time options, that can be enabled by setting `WITH_WINDOWS_UTF8_FILENAMES` to true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4469
Differential Revision: D10356011
Pulled By: yiwu-arbug
fbshipit-source-id: 27b6ae9171f209085894cdf80069e8a896642044
Summary:
As you know, almost all compilers support "pragma once" keyword instead of using include guards. To be keep consistency between header files, all header files are edited.
Besides this, try to fix some warnings about loss of data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4339
Differential Revision: D9654990
Pulled By: ajkr
fbshipit-source-id: c2cf3d2d03a599847684bed81378c401920ca848
Summary:
We want to sample the file I/O issued by RocksDB and report the function calls. This requires us to include the file paths otherwise it's hard to tell what has been going on.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4039
Differential Revision: D8670178
Pulled By: riversand963
fbshipit-source-id: 97ee806d1c583a2983e28e213ee764dc6ac28f7a
Summary:
Although delete scheduler implementation allows for the interface not to be supported, the delete_scheduler_test does not allow for that.
Address compiler warnings
Make sst_dump_test use test directory structure as the current execution directory may not be writiable.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4221
Differential Revision: D9210152
Pulled By: siying
fbshipit-source-id: 381a74511e969ecb8089d5c4b4df87dc30c8df63
Summary:
Lint is not happy with some new code recently committed. Format them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4161
Differential Revision: D8940582
Pulled By: siying
fbshipit-source-id: c9b43b1ef8c88b5e923911058b44eb77234b36b7
Summary: Windows requires new/delete for memory allocations to be overriden. Refactor to be less intrusive.
Differential Revision: D8878047
Pulled By: siying
fbshipit-source-id: 35f2b5fec2f88ea48c9be926539c6469060aab36
Summary:
We potentially need this information for tracing, profiling and diagnosis.
Closes https://github.com/facebook/rocksdb/pull/4026
Differential Revision: D8555214
Pulled By: riversand963
fbshipit-source-id: 4263e06c00b6d5410b46aa46eb4e358ff2161dd2
Summary:
so they could be overriden
Closes https://github.com/facebook/rocksdb/pull/4025
Differential Revision: D8526287
Pulled By: siying
fbshipit-source-id: 9537b299dc907b4d1eeaf77a8784b13cb058280d
Summary:
Fix a crash in `WinEnvIO::GetSectorSize` that happens on old Windows systems (e.g Windows 7).
On old Windows systems that don't support querying StorageAccessAlignmentProperty using IOCTL_STORAGE_QUERY_PROPERTY, the flow calls a different DeviceIoControl with nullptr as lpBytesReturned.
When the code reaches this point, we get an access violation.
Closes https://github.com/facebook/rocksdb/pull/3975
Differential Revision: D8385186
Pulled By: ajkr
fbshipit-source-id: fae4c9b4b0a52c8a10182e1b35bcaa30dc393bbb
Summary:
PR https://github.com/facebook/rocksdb/pull/3838 made some changes that triggers lint warnings.
Run `make format` to fix formatting as suggested by siying .
Also piggyback two changes:
1) fix singleton destruction order for windows and posix env
2) fix two clang warnings
Closes https://github.com/facebook/rocksdb/pull/3954
Differential Revision: D8272041
Pulled By: miasantreble
fbshipit-source-id: 7c4fd12bd17aac13534520de0c733328aa3c6c9f
Summary:
Windows does not have LD_PRELOAD mechanism to override all memory allocation functions and ZSTD makes use of C-tuntime calloc. During flushes and compactions default system allocator fragments and the system slows down considerably.
For builds with jemalloc we employ an advanced ZSTD context creation API that re-directs memory allocation to jemalloc. To reduce the cost of context creation on each block we cache ZSTD context within the block based table builder while a new SST file is being built, this will help all platform builds including those w/o jemalloc. This avoids system allocator fragmentation and improves the performance.
The change does not address random reads and currently on Windows reads with ZSTD regress as compared with SNAPPY compression.
Closes https://github.com/facebook/rocksdb/pull/3838
Differential Revision: D8229794
Pulled By: miasantreble
fbshipit-source-id: 719b622ab7bf4109819bc44f45ec66f0dd3ee80d
Summary:
Catch up with Posix features
NewWritableRWFile must fail when file does not exists
Implement Env::Truncate()
Adjust Env options optimization functions
Implement MemoryMappedBuffer on Windows.
Closes https://github.com/facebook/rocksdb/pull/3857
Differential Revision: D8053610
Pulled By: ajkr
fbshipit-source-id: ccd0d46c29648a9f6f496873bc1c9d6c5547487e
Summary:
to workaround issue of http://tracker.ceph.com/issues/21422 .
and in tcmalloc aligned_alloc and posix_memalign() are basically the
same thing. the same applies to GNU glibc.
fixes#3175
Signed-off-by: Kefu Chai <tchaikov@gmail.com>
Closes https://github.com/facebook/rocksdb/pull/3862
Differential Revision: D8147930
Pulled By: yiwu-arbug
fbshipit-source-id: 355afe93c4dd0a96a0d711ef190e8b86fbe8d11d
Summary:
Delete archive directory before WAL folder
since archive may be contained as a subfolder.
Also improve loop readability.
Closes https://github.com/facebook/rocksdb/pull/3797
Differential Revision: D7866378
Pulled By: riversand963
fbshipit-source-id: 0c45d97677ce6fbefa3f8d602ef5e2a2a925e6f5
Summary:
Returning bytes_read causes the caller to call GetLastError()
to report failure but the lasterror may be overwritten by then
so we lose the error code.
Fix up CMake file to include xpress source code only when needed.
Fix warning for the uninitialized var.
Closes https://github.com/facebook/rocksdb/pull/3795
Differential Revision: D7832935
Pulled By: anand1976
fbshipit-source-id: 4be21affb9b85d361b96244f4ef459f492b7cb2b
Summary:
This patch addressed several issues.
Portability including db_test std::thread -> port::Thread Cc: @
and %z to ROCKSDB portable macro. Cc: maysamyabandeh
Implement Env::AreFilesSame
Make the implementation of file unique number more robust
Get rid of C-runtime and go directly to Windows API when dealing
with file primitives.
Implement GetSectorSize() and aling unbuffered read on the value if
available.
Adjust Windows Logger for the new interface, implement CloseImpl() Cc: anand1976
Fix test running script issue where $status var was of incorrect scope
so the failures were swallowed and not reported.
DestroyDB() creates a logger and opens a LOG file in the directory
being cleaned up. This holds a lock on the folder and the cleanup is
prevented. This fails one of the checkpoin tests. We observe the same in production.
We close the log file in this change.
Fix DBTest2.ReadAmpBitmapLiveInCacheAfterDBClose failure where the test
attempts to open a directory with NewRandomAccessFile which does not
work on Windows.
Fix DBTest.SoftLimit as it is dependent on thread timing. CC: yiwu-arbug
Closes https://github.com/facebook/rocksdb/pull/3552
Differential Revision: D7156304
Pulled By: siying
fbshipit-source-id: 43db0a757f1dfceffeb2b7988043156639173f5b
Summary:
_endthreadex does not return and thus objects
for stack destructors do not run. This creates a memory leak.
We remove the calls since _enthreadex called automatically after the
threadproc returns i.e. thread exits.
Closes https://github.com/facebook/rocksdb/pull/3542
Differential Revision: D7088713
Pulled By: ajkr
fbshipit-source-id: 749ecafc6a9572f587f76e516547e07734349a54
Summary:
Right now, users will encounter unexpected bahavior if they use key or value larger than 4GB. We should explicitly fail the queriers.
Closes https://github.com/facebook/rocksdb/pull/3484
Differential Revision: D6953895
Pulled By: siying
fbshipit-source-id: b60491e1af064fc5d52971956661f6c18ceac24f
Summary:
BlockTest.BlockReadAmpBitmap is too slow and times out in some environments. Speed it up by:
(1) improve the way the verification is done. With this it is 5 times faster
(2) run fewer tests for large blocks. This cut it down by another 10 times.
Now it can finish in similar time as other tests.
Closes https://github.com/facebook/rocksdb/pull/3313
Differential Revision: D6643711
Pulled By: siying
fbshipit-source-id: c2397d666eab5421a78ca87e1e45491e0f832a6d
Summary:
FILE_FLAG_WRITE_THROUGH is for disabling device on-board cache in windows API, which should be disabled if user doesn't need system cache.
There was a perf issue related with this, we found during memtable flush, the high percentile latency jumps significantly. During profiling, we found those high latency (P99.9) read requests got queue-jumped by write requests from memtable flush and takes 80ms or even more time to wait, even when SSD overall IO throughput is relatively low.
After enabling FILE_FLAG_WRITE_THROUGH, we rerun the test found high percentile latency drops a lot without observable impact on writes.
Scenario 1: 40MB/s + 40MB/s R/W compaction throughput
Original | FILE_FLAG_WRITE_THROUGH | Percentage reduction
---------------------------------------------------------------
P99.9 | 56.897 ms | 35.593 ms | -37.4%
P99 | 3.905 ms | 3.896 ms | -2.8%
Scenario 2: 14MB/s + 14MB/s R/W compaction throughput, cohosted with 100+ other rocksdb instances have manually triggered memtable flush operations (memtable is tiny), creating a lot of randomized the small file writes operations during test.
Original | FILE_FLAG_WRITE_THROUGH | Percentage reduction
---------------------------------------------------------------
P99.9 | 86.227 ms | 50.436 ms | -41.5%
P99 | 8.415 ms | 3.356 ms | -60.1%
Closes https://github.com/facebook/rocksdb/pull/3225
Differential Revision: D6624174
Pulled By: miasantreble
fbshipit-source-id: 321b86aee9d74470840c70e5d0d4fa9880660a91
Summary:
Fix a race condition when we create a thread and immediately destroy
This case should be supported.
What happens is that the thread function needs the Data instance
to actually run but has no shared ownership and must rely on the
WindowsThread instance to continue existing.
To address this we change unique_ptr to shared_ptr and then
acquire an additional refcount for the threadproc which destroys it
just before the thread exit.
We choose to allocate shared_ptr instance on the heap as this allows
the original thread to continue w/o waiting for the new thread to start
running.
Closes https://github.com/facebook/rocksdb/pull/3240
Differential Revision: D6511324
Pulled By: yiwu-arbug
fbshipit-source-id: 4633ff7996daf4d287a9fe34f60c1dd28cf4ff36
Summary:
MSVC does not support unused attribute at this time. A separate assignment line fixes the issue probably by being counted as usage for MSVC and it no longer complains about unused var.
Closes https://github.com/facebook/rocksdb/pull/3048
Differential Revision: D6126272
Pulled By: maysamyabandeh
fbshipit-source-id: 4907865db45fd75a39a15725c0695aaa17509c1f
Summary:
snprintf is defined as _snprintf, which doesn't exist in the std
namespace.
Closes https://github.com/facebook/rocksdb/pull/2298
Differential Revision: D5070457
Pulled By: yiwu-arbug
fbshipit-source-id: 6e1659ac3e86170653b174578da5a8ed16812cbb
Summary:
Add -DPORTABLE=1
port::cacheline_aligned_alloc() has arguments swapped which prevents every single test from running.
Closes https://github.com/facebook/rocksdb/pull/2815
Differential Revision: D5751661
Pulled By: siying
fbshipit-source-id: e0857d6e138ec46035b3c23d7c3c751901a0a4a0
Summary:
GCC < 5 + ASAN does not instrument aligned_alloc, which can make ASAN
report false-positive with "free on address which was not malloc" error.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61693
Also suppress leak warning with LRUCache::DisownData().
Closes https://github.com/facebook/rocksdb/pull/2783
Differential Revision: D5696465
Pulled By: yiwu-arbug
fbshipit-source-id: 87c607c002511fa089b18cc35e24909bee0e74b4
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
Summary:
Make default impl return NoSupported so the db_blob
tests exist in a meaningful manner.
Replace std::thread to port::Thread
Closes https://github.com/facebook/rocksdb/pull/2465
Differential Revision: D5275563
Pulled By: yiwu-arbug
fbshipit-source-id: cedf1a18a2c05e20d768c1308b3f3224dbd70ab6
Summary:
Previously users could set `max_background_flushes=0` to force rocksdb to use a single thread pool for both background flushes and compactions. That'll no longer be possible since I'm going to deprecate `max_background_flushes` and `max_background_compactions` in favor of a single option. This diff introduces a new way to force a single thread pool: when high-pri pool has zero threads, all background jobs will be submitted to low-pri pool.
Note the majority of the code change is adding `Env::GetBackgroundThreads()`, which is necessary to check whether the user has provided a zero-sized thread pool.
Closes https://github.com/facebook/rocksdb/pull/2204
Differential Revision: D4936256
Pulled By: ajkr
fbshipit-source-id: 929a07a0c0705f7766f5339cd013ff74e90d6e01
Summary:
This was exposed by a48a62d, which made NDEBUG the default for cmake
builds.
Closes https://github.com/facebook/rocksdb/pull/2315
Differential Revision: D5079583
Pulled By: sagar0
fbshipit-source-id: c614e96a40df016a834a62b6236852265e7ee4db
Summary:
- added a feature test in build_detect_platform to check whether sched_getcpu() is available. glibc offers it only on some platforms (e.g., linux but not mac); this way should be easier than maintaining a list of platforms on which it's available.
- refactored PhysicalCoreID() to be simpler / less repetitive. ordered the conditional compilation clauses from most-to-least preferred
Closes https://github.com/facebook/rocksdb/pull/2272
Differential Revision: D5038093
Pulled By: ajkr
fbshipit-source-id: 81d7db3cc620250de220bdeb3194b2b3d7673de7
Summary:
Updated PhysicalCoreID() to use sched_getcpu() on x86_64 for glibc >= 2.22. Added a new
function named GetCPUID() that calls sched_getcpu(), to avoid repeated code. This change is done as per the comments of PR: https://github.com/facebook/rocksdb/pull/2230
Signed-off-by: Jos Collin <jcollin@redhat.com>
Closes https://github.com/facebook/rocksdb/pull/2260
Differential Revision: D5025734
Pulled By: ajkr
fbshipit-source-id: f4cca68c12573cafcf8531e7411a1e733bbf8eef
Summary:
RocksDB is compiled as part of MyRocks (MySQL storage engine) build.
MySQL already defines `CACHE_LINE_SIZE` and therefore we're getting a
conflict. Change RocksDB definition to be more cognizant of this.
Closes https://github.com/facebook/rocksdb/pull/2257
Differential Revision: D5013188
Pulled By: gunnarku
fbshipit-source-id: cfa76fe99f90dcd82aa09204e2f1f35e07a82b41
Summary:
- downcase includes for case-sensitive filesystems
- give targets the same name (librocksdb) on all platforms
With this patch it is possible to cross-compile RocksDB for Windows
from a Linux host using mingw.
cc yuslepukhin orgads
Closes https://github.com/facebook/rocksdb/pull/2107
Differential Revision: D4849784
Pulled By: siying
fbshipit-source-id: ad26ed6b4d393851aa6551e6aa4201faba82ef60
Summary: Checked the return value of __get_cpuid(). Implemented the else case where the arch is different from i386 and x86_64.
Pulled By: ajkr
Differential Revision: D4973496
fbshipit-source-id: c40fdef5840364c2a79b1d11df0db5d4ec3d6a4a
Summary:
Remove double buffering on RandomRead on Windows.
With more logic appear in file reader/write Read no longer
obeys forwarding calls to Windows implementation.
Previously direct_io (unbuffered) was only available on Windows
but now is supported as generic.
We remove intermediate buffering on Windows.
Remove random_access_max_buffer_size option which was windows specific.
Non-zero values for that opton introduced unnecessary lock contention.
Remove Env::EnableReadAhead(), Env::ShouldForwardRawRequest() that are
no longer necessary.
Add aligned buffer reads for cases when requested reads exceed read ahead size.
Closes https://github.com/facebook/rocksdb/pull/2105
Differential Revision: D4847770
Pulled By: siying
fbshipit-source-id: 8ab48f8e854ab498a4fd398a6934859792a2788f
Summary:
Replacement of #2147
The change was squashed due to a lot of conflicts.
Closes https://github.com/facebook/rocksdb/pull/2194
Differential Revision: D4929799
Pulled By: siying
fbshipit-source-id: 5cd49c254737a1d5ac13f3c035f128e86524c581
Summary:
Move some files under util/ to new directories env/, monitoring/ options/ and cache/
Closes https://github.com/facebook/rocksdb/pull/2090
Differential Revision: D4833681
Pulled By: siying
fbshipit-source-id: 2fd8bef
Summary:
There still are many warnings (most of them about invalid printf format
for long long), but it builds if FAIL_ON_WARNINGS is disabled.
Closes https://github.com/facebook/rocksdb/pull/2052
Differential Revision: D4807355
Pulled By: siying
fbshipit-source-id: ef03786
Summary:
This fixes an issue when the most recent readers assume that alignment is always set even if direct io is off.
Also adjust slightly appveyor script to run db_basic_test cases concurrently.
Closes https://github.com/facebook/rocksdb/pull/1959
Differential Revision: D4671972
Pulled By: IslamAbdelRahman
fbshipit-source-id: 1886620
Summary:
introduce new methods into a public threadpool interface,
- allow submission of std::functions as they allow greater flexibility.
- add Joining methods to the implementation to join scheduled and submitted jobs with
an option to cancel jobs that did not start executing.
- Remove ugly `#ifdefs` between pthread and std implementation, make it uniform.
- introduce pimpl for a drop in replacement of the implementation
- Introduce rocksdb::port::Thread typedef which is a replacement for std::thread. On Posix Thread defaults as before std::thread.
- Implement WindowsThread that allocates memory in a more controllable manner than windows std::thread with a replaceable implementation.
- should be no functionality changes.
Closes https://github.com/facebook/rocksdb/pull/1823
Differential Revision: D4492902
Pulled By: siying
fbshipit-source-id: c74cb11
Summary:
also change variable name `direct_io_` to `use_direct_io_` in WritableFile to make it consistent with read path.
Closes https://github.com/facebook/rocksdb/pull/1770
Differential Revision: D4416435
Pulled By: lightmark
fbshipit-source-id: 4143c53
Summary:
Enable directIO on WritableFileImpl::Append
with offset being current length of the file.
Enable UniqueID tests on Windows, disable others but
leeting them to compile. Unique tests are valuable to
detect failures on different filesystems and upcoming
ReFS.
Clear output in WinEnv Getchildren.This is different from
previous strategy, do not touch output on failure.
Make sure DBTest.OpenWhenOpen works with windows error message
Closes https://github.com/facebook/rocksdb/pull/1746
Differential Revision: D4385681
Pulled By: IslamAbdelRahman
fbshipit-source-id: c07b702
Summary:
To support scenarios where we want all instances of `Mutex` be adaptive
we're adding a conditional `#define` so that the desired behavior can be
easily enabled.
Closes https://github.com/facebook/rocksdb/pull/1710
Differential Revision: D4359863
Pulled By: gunnarku
fbshipit-source-id: 2f1e2f8
Summary:
The address of the array of string pointers is returned as the function result of backtrace_symbols(). This array is malloced by backtrace_symbols(), and must be freed by the caller.
Closes https://github.com/facebook/rocksdb/pull/1692
Differential Revision: D4355737
Pulled By: IslamAbdelRahman
fbshipit-source-id: 5742035
Summary:
It'd be nice to use the error status type to distinguish
between user error and system error. For example, GetChildren can fail
listing a backup directory's contents either because a bad path was provided
(user error) or because an operation failed, e.g., a remote storage service
call failed (system error). In the former case, we want to continue and treat
the backup directory as empty; in the latter case, we want to immediately
propagate the error to the caller.
This diff uses NotFound to indicate user error and IOError to indicate
system error. Previously IOError indicated both.
Closes https://github.com/facebook/rocksdb/pull/1644
Differential Revision: D4312157
Pulled By: ajkr
fbshipit-source-id: 51b4f24
Summary:
This diff split ThreadPool to
-ThreadPool (abstract interface exposed in include/rocksdb/threadpool.h)
-ThreadPoolImpl (actual implementation in util/threadpool_imp.h)
This allow us to expose ThreadPool to the user so we can use it as an option later
Test Plan: existing unit tests
Reviewers: andrewkr, yiwu, yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D62085
* stack_trace,cc: The current Stacktrace code does not compile for FreeBSD
So set it to generate empty routines
* stack_trace,cc: The current Stacktrace code does not compile for FreeBSD
Use the definition also used in other commits
Summary: When rate_bytes_per_sec * refill_period_us_ overflows, the actual limited rate is very low. Handle this case so the rate will be large.
Test Plan: Add a unit test for it.
Reviewers: IslamAbdelRahman, andrewkr
Reviewed By: andrewkr
Subscribers: yiwu, lightmark, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D58929
For ease of reuse and customization as a library
without wrapping.
WinEnvThreads is a class for replacement.
WintEnvIO is a class for reuse and behavior override.
Added private virtual functions for custom override
of fallocate pread for io classes.
Conditionally retrofit thread_posix for use with std::thread
and reuse the same logic. Posix users continue using Posix interfaces.
Enable XPRESS compression in test runs.
Fix master introduced signed/unsigned mismatch.
* Musl libc does not provide adaptive mutex. Added feature test for PTHREAD_MUTEX_ADAPTIVE_NP.
* Musl libc does not provide backtrace(3). Added a feature check for backtrace(3).
* Fixed compiler error.
* Musl libc does not implement backtrace(3). Added platform check for libexecinfo.
* Alpine does not appear to support gcc -pg option. By default (gcc has PIE option enabled) it fails with:
gcc: error: -pie and -pg|p|profile are incompatible when linking
When -fno-PIE and -nopie are used it fails with:
/usr/lib/gcc/x86_64-alpine-linux-musl/5.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: cannot find gcrt1.o: No such file or directory
Added gcc -pg platform test and output PROFILING_FLAGS accordingly. Replaced pg var in Makefile with PROFILING_FLAGS.
* fix segfault when TEST_IOCTL_FRIENDLY_TMPDIR is undefined and default candidates are not suitable
* use ASSERT_DOUBLE_EQ instead of ASSERT_EQ
* When compiled with ROCKSDB_MALLOC_USABLE_SIZE UniversalCompactionFourPaths and UniversalCompactionSecondPathRatio tests fail due to premature memtable flushes on systems with 16-byte alignment. Arena runs out of block space before GenerateNewFile() completes.
Increased options.write_buffer_size.
Comparable with Snappy on comp ratio.
Implemented using Windows API, does not require external package.
Avaiable since Windows 8 and server 2012.
Use -DXPRESS=1 with CMake to enable.
Summary: I broke it in D53781.
Test Plan: tried the same code in util/env_posix.cc and it compiled successfully
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D54303
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
This change impacts only non-buffered I/O on Windows.
Currently, there is a buffer per RandomAccessFile
instance that is protected by a lock. The reason we
maintain the buffer is non-buffered I/O requires an aligned
buffer to work.
XPerf traces demonstrate that we accumulate a considerable
wait time while waiting for that lock.
This change enables to set random access buffer size to zero
which would indicate a per request allocation.
We are expecting that allocation expense would be much less than
I/O costs plus wait time due to the fact that the memory heap
would tend to re-use page aligned allocations especially with the
use of Jemalloc.
This change does not affect buffer use as a read_ahead_buffer for
compaction purposes.
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
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
* conversion from 'size_t' to 'type', by add static_cast
Tested:
* by build solution on Windows, Linux locally,
* run tests
* build CI system successful
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.
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
introduce a new DBOption random_access_max_buffer_size to limit
the size of the random access buffer used for unbuffered access.
Implement read ahead buffering when enabled.
To that effect propagate compaction_readahead_size and the new option
to the env options to make it available for the implementation.
Add Hint() override so SetupForCompaction() call would call Hint()
readahead can now be setup from both Hint() and EnableReadAhead()
Add new option random_access_max_buffer_size support
db_bench, options_helper to make it string parsable
and the unit test.
Summary:
Give a name for every kill point, and allow users to disable some kill points based on prefixes. The kill points can be passed by db_stress through a command line paramter. This provides a way for users to boost the chance of triggering low frequency kill points
This allow follow up changes in crash test scripts to improve crash test coverage.
Test Plan:
Manually run db_stress with variable values of --kill_random_test and --kill_prefix_blacklist. Like this:
--kill_random_test=2 --kill_prefix_blacklist=Posix,WritableFileWriter::Append,WritableFileWriter::WriteBuffered,WritableFileWriter::Sync
Reviewers: igor, kradhakrishnan, rven, IslamAbdelRahman, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D48735
Summary:
This mirrors https://reviews.facebook.net/D45645
Currently, mmap returns IOError when user tries to read
data past the end of the file. This diff changes the behavior.
Now, we return just the bytes that we can, and report the size
we returned via a Slice result. This is consistent with non-mmap
behavior and also pread() system call.
Summary. A change https://reviews.facebook.net/differential/diff/224721/
Has attempted to move common functionality out of platform dependent
code to a new facility called file_reader_writer.
This includes:
- perf counters
- Buffering
- RateLimiting
However, the change did not attempt to refactor Windows code.
To mitigate, we introduce new quering interfaces such as UseOSBuffer(),
GetRequiredBufferAlignment() and ReaderWriterForward()
for pure forwarding where required.
Introduce WritableFile got a new method Truncate(). This is to communicate
to the file as to how much data it has on close.
- When space is pre-allocated on Linux it is filled with zeros implicitly,
no such thing exist on Windows so we must truncate file on close.
- When operating in unbuffered mode the last page is filled with zeros but we still want to truncate.
Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has
no idea about the file true size.
This means that Close() on the wrapper level must always include
Truncate() as well as wrapper __dtor should call Close() and
against double Close().
Move buffered/unbuffered write logic to the wrapper.
Utilize Aligned buffer class.
Adjust tests and implement Truncate() where necessary.
Come up with reasonable defaults for new virtual interfaces.
Forward calls for RandomAccessReadAhead class to avoid double
buffering and locking (double locking in unbuffered mode on WIndows).
Summary: We should never set max_open_files to be bigger than the system's ulimit. Otherwise we will get "Too many open files" errors. See an example in this Travis run: https://travis-ci.org/facebook/rocksdb/jobs/79591566
Test Plan:
make check
I will also verify that max_max_open_files is reasonable.
Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D46551
Previous change for the function
555ca3e7b7 (diff-bdc04e0404c2db4fd3ac5118a63eaa4a)
made use of the QueryPerformanceCounter to return microseconds values that do not repeat
as std::chrono::system_clock returned values that made auto_roll_logger_test fail.
The interface documentation does not state that we need to return
system time describing the return value as a number of microsecs since some
moment in time. However, because on Linux it is implemented using gettimeofday
various pieces of code (such as GenericRateLimiter) took advantage of that
and make use of NowMicros() as a system timestamp. Thus the previous change
broke rate_limiter_test on Windows.
In addition, the interface name NowMicros() suggests that it is actually
a timestamp so people use it as such.
This change makes use of the new system call on Windows that returns
system time with required precision. This change preserves the fix
for auto_roll_logger_test and fixes rate_limiter_test.
Note that DBTest.RateLimitingTest still fails due to a separately reported issue.
Peter Dillinger