Summary:
The main improvement here is to not include `.` or `..` in the results of `Env::GetChildren`. The occurrence of `.` or `..`; it is non-portable, dependent on the Operating System and the File System. See: https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html
There were lots of duplicate checks spread through the RocksDB codebase previously to skip `.` and `..`. This new removes the need for those at the source.
Also some minor fixes to `Env::GetChildren`:
* Improve error handling in POSIX implementation
* Remove unnecessary array allocation on Windows
* Fix struct name for Windows Non-UTF-8 API
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7819
Reviewed By: ajkr
Differential Revision: D25837394
Pulled By: jay-zhuang
fbshipit-source-id: 1e137e7218d38b450af9c083f73d5357abcbba2e
Summary:
Add new API WriteBufferManager::dummy_entries_in_cache_usage() which reports the dummy entries size stored in cache to account for DataBlocks in WriteBufferManager.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7837
Test Plan: Updated test ./write_buffer_manager_test
Reviewed By: ajkr
Differential Revision: D25794312
Pulled By: akankshamahajan15
fbshipit-source-id: 197f5e8701e3dc57a7df72dab1735624f90daf4b
Summary:
In RocksDB, when IO error happens, the flags of IOStatus can be set. If the IOStatus is set as "File Scope IO Error", it indicate that the error is constrained in the file level. Since RocksDB does not continues write data to a file when any IO Error happens, File Scope IO Error can be treated the same as Retryable IO Error. Adding the logic to ErrorHandler::SetBGError to include the file scope IO Error in its error handling logic, which is the same as retryable IO Error.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7840
Test Plan: added new unit tests in error_handler_fs_test. make check
Reviewed By: anand1976
Differential Revision: D25820481
Pulled By: zhichao-cao
fbshipit-source-id: 69cabd3d010073e064d6142ce1cabf341b8a6806
Summary:
Previously we only had a debug assertion to check the right generator was being used for verification. However a user hit a problem in production where their factory was creating the wrong generator for some files, leading to checksum mismatches. It would have been easier to debug if we verified in optimized builds that the generator with the proper name is used. This PR adds such verification.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7824
Reviewed By: zhichao-cao
Differential Revision: D25740254
Pulled By: ajkr
fbshipit-source-id: a6231521747605021bad3231484b5d4f99f4044f
Summary:
So that we can more easily get aggregate live table data such
as total filter, index, and data sizes.
Also adds ldb support for getting properties
Also fixed some missing/inaccurate related comments in db.h
For example:
$ ./ldb --db=testdb get_property rocksdb.aggregated-table-properties
rocksdb.aggregated-table-properties.data_size: 102871
rocksdb.aggregated-table-properties.filter_size: 0
rocksdb.aggregated-table-properties.index_partitions: 0
rocksdb.aggregated-table-properties.index_size: 2232
rocksdb.aggregated-table-properties.num_data_blocks: 100
rocksdb.aggregated-table-properties.num_deletions: 0
rocksdb.aggregated-table-properties.num_entries: 15000
rocksdb.aggregated-table-properties.num_merge_operands: 0
rocksdb.aggregated-table-properties.num_range_deletions: 0
rocksdb.aggregated-table-properties.raw_key_size: 288890
rocksdb.aggregated-table-properties.raw_value_size: 198890
rocksdb.aggregated-table-properties.top_level_index_size: 0
$ ./ldb --db=testdb get_property rocksdb.aggregated-table-properties-at-level1
rocksdb.aggregated-table-properties-at-level1.data_size: 80909
rocksdb.aggregated-table-properties-at-level1.filter_size: 0
rocksdb.aggregated-table-properties-at-level1.index_partitions: 0
rocksdb.aggregated-table-properties-at-level1.index_size: 1787
rocksdb.aggregated-table-properties-at-level1.num_data_blocks: 81
rocksdb.aggregated-table-properties-at-level1.num_deletions: 0
rocksdb.aggregated-table-properties-at-level1.num_entries: 12466
rocksdb.aggregated-table-properties-at-level1.num_merge_operands: 0
rocksdb.aggregated-table-properties-at-level1.num_range_deletions: 0
rocksdb.aggregated-table-properties-at-level1.raw_key_size: 238210
rocksdb.aggregated-table-properties-at-level1.raw_value_size: 163414
rocksdb.aggregated-table-properties-at-level1.top_level_index_size: 0
$
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7779
Test Plan: Added a test to ldb_test.py
Reviewed By: jay-zhuang
Differential Revision: D25653103
Pulled By: pdillinger
fbshipit-source-id: 2905469a08a64dd6b5510cbd7be2e64d3234d6d3
Summary:
Primarily this change refactors the optimize_filters_for_memory
code for Bloom filters, based on malloc_usable_size, to also work for
Ribbon filters.
This change also replaces the somewhat slow but general
BuiltinFilterBitsBuilder::ApproximateNumEntries with
implementation-specific versions for Ribbon (new) and Legacy Bloom
(based on a recently deleted version). The reason is to emphasize
speed in ApproximateNumEntries rather than 100% accuracy.
Justification: ApproximateNumEntries (formerly CalculateNumEntry) is
only used by RocksDB for range-partitioned filters, called each time we
start to construct one. (In theory, it should be possible to reuse the
estimate, but the abstractions provided by FilterPolicy don't really
make that workable.) But this is only used as a heuristic estimate for
hitting a desired partitioned filter size because of alignment to data
blocks, which have various numbers of unique keys or prefixes. The two
factors lead us to prioritize reasonable speed over 100% accuracy.
optimize_filters_for_memory adds extra complication, because precisely
calculating num_entries for some allowed number of bytes depends on state
with optimize_filters_for_memory enabled. And the allocator-agnostic
implementation of optimize_filters_for_memory, using malloc_usable_size,
means we would have to actually allocate memory, many times, just to
precisely determine how many entries (keys) could be added and stay below
some size budget, for the current state. (In a draft, I got this
working, and then realized the balance of speed vs. accuracy was all
wrong.)
So related to that, I have made CalculateSpace, an internal-only API
only used for testing, non-authoritative also if
optimize_filters_for_memory is enabled. This simplifies some code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7774
Test Plan:
unit test updated, and for FilterSize test, range of tested
values is greatly expanded (still super fast)
Also tested `db_bench -benchmarks=fillrandom,stats -bloom_bits=10 -num=1000000 -partition_index_and_filters -format_version=5 [-optimize_filters_for_memory] [-use_ribbon_filter]` with temporary debug output of generated filter sizes.
Bloom+optimize_filters_for_memory:
1 Filter size: 197 (224 in memory)
134 Filter size: 3525 (3584 in memory)
107 Filter size: 4037 (4096 in memory)
Total on disk: 904,506
Total in memory: 918,752
Ribbon+optimize_filters_for_memory:
1 Filter size: 3061 (3072 in memory)
110 Filter size: 3573 (3584 in memory)
58 Filter size: 4085 (4096 in memory)
Total on disk: 633,021 (-30.0%)
Total in memory: 634,880 (-30.9%)
Bloom (no offm):
1 Filter size: 261 (320 in memory)
1 Filter size: 3333 (3584 in memory)
240 Filter size: 3717 (4096 in memory)
Total on disk: 895,674 (-1% on disk vs. +offm; known tolerable overhead of offm)
Total in memory: 986,944 (+7.4% vs. +offm)
Ribbon (no offm):
1 Filter size: 2949 (3072 in memory)
1 Filter size: 3381 (3584 in memory)
167 Filter size: 3701 (4096 in memory)
Total on disk: 624,397 (-30.3% vs. Bloom)
Total in memory: 690,688 (-30.0% vs. Bloom)
Note that optimize_filters_for_memory is even more effective for Ribbon filter than for cache-local Bloom, because it can close the unused memory gap even tighter than Bloom filter, because of 16 byte increments for Ribbon vs. 64 byte increments for Bloom.
Reviewed By: jay-zhuang
Differential Revision: D25592970
Pulled By: pdillinger
fbshipit-source-id: 606fdaa025bb790d7e9c21601e8ea86e10541912
Summary:
When ConcurrentTaskLimiter is enabled and there are too many outstanding compactions, BackgroundCompaction returns Status::Busy(), which shouldn't be treat as compaction failure.
This caused performance issue when outstanding compactions reached the limit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7739
Reviewed By: cheng-chang
Differential Revision: D25508319
Pulled By: ltamasi
fbshipit-source-id: 3b181b16ada0ca3393cfa3a7412985764e79c719
Summary:
Deprecate CalculateNumEntry and replace with
ApproximateNumEntries (better name) using size_t instead of int and
uint32_t, to minimize confusing casts and bad overflow behavior
(possible though probably not realistic). Bloom sizes are now explicitly
capped at max size supported by implementations: just under 4GiB for
fv=5 Bloom, and just under 512MiB for fv<5 Legacy Bloom. This
hardening could help to set up for fuzzing.
Also, since RocksDB only uses this information as an approximation
for trying to hit certain sizes for partitioned filters, it's more important
that the function be reasonably fast than for it to be completely
accurate. It's hard enough to be 100% accurate for Ribbon (currently
reversing CalculateSpace) that adding optimize_filters_for_memory
into the mix is just not worth trying to be 100% accurate for num
entries for bytes.
Also:
- Cleaned up filter_policy.h to remove MSVC warning handling and
potentially unsafe use of exception for "not implemented"
- Correct the number of entries limit beyond which current Ribbon
implementation falls back on Bloom instead.
- Consistently use "num_entries" rather than "num_entry"
- Remove LegacyBloomBitsBuilder::CalculateNumEntry as it's essentially
obsolete from general implementation
BuiltinFilterBitsBuilder::CalculateNumEntries.
- Fix filter_bench to skip some tests that don't make sense when only
one or a small number of filters has been generated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7726
Test Plan:
expanded existing unit tests for CalculateSpace /
ApproximateNumEntries. Also manually used filter_bench to verify Legacy and
fv=5 Bloom size caps work (much too expensive for unit test). Note that
the actual bits per key is below requested due to space cap.
$ ./filter_bench -impl=0 -bits_per_key=20 -average_keys_per_filter=256000000 -vary_key_count_ratio=0 -m_keys_total_max=256 -allow_bad_fp_rate
...
Total size (MB): 511.992
Bits/key stored: 16.777
...
$ ./filter_bench -impl=2 -bits_per_key=20 -average_keys_per_filter=2000000000 -vary_key_count_ratio=0 -m_keys_total_max=2000
...
Total size (MB): 4096
Bits/key stored: 17.1799
...
$
Reviewed By: jay-zhuang
Differential Revision: D25239800
Pulled By: pdillinger
fbshipit-source-id: f94e6d065efd31e05ec630ae1a82e6400d8390c4
Summary:
Ensure that when direct IO is enabled and a compressed block cache is
configured, MultiGet inserts compressed data blocks into the compressed
block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7756
Test Plan: Add unit test to db_basic_test
Reviewed By: cheng-chang
Differential Revision: D25416240
Pulled By: anand1976
fbshipit-source-id: 75d57526370c9c0a45ff72651f3278dbd8a9086f
Summary:
When 2 phase commit is enabled, if there are prepared data in a WAL, the WAL should be kept, the minimum log number for such a WAL is written to MANIFEST during flush. In atomic flush, such information is not written to MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7570
Test Plan: Added a new unit test `DBAtomicFlushTest.ManualFlushUnder2PC`, this test fails in atomic flush without this PR, after this PR, it succeeds.
Reviewed By: riversand963
Differential Revision: D24394222
Pulled By: cheng-chang
fbshipit-source-id: 60ce74b21b704804943be40c8de01b41269cf116
Summary:
Add timestamp to the `CompactRange()` and `GetApproximateSizes` range keys if needed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7684
Test Plan: make check
Reviewed By: riversand963
Differential Revision: D25015421
Pulled By: jay-zhuang
fbshipit-source-id: 51ca0756087eb053a3b11801e5c7ce1c6e2d38a9
Summary:
WAL may be truncated to an incomplete record due to crash while writing
the last record or corruption. In the former case, no hole will be
produced since no ACK'd data was lost. In the latter case, a hole could
be produced without this PR since we proceeded to recover the next WAL
as if nothing happened. This PR changes the record reading code to
always report a corruption for incomplete records in
`kPointInTimeRecovery` mode, and the upper layer will only ignore them
if the next WAL has consecutive seqnum (i.e., we are guaranteed no
hole).
While this solves the hole problem for the case of incomplete
records, the possibility is still there if the WAL is corrupted by
truncation to an exact record boundary. This PR also regresses how much data
can be recovered when writes are mixed with/without
`WriteOptions::disableWAL`, as then we can not distinguish between a
seqnum gap caused by corruption and a seqnum gap caused by a `disableWAL` write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7701
Test Plan:
Interestingly there already was a test for this case
(`DBWALTestWithParams.kPointInTimeRecovery`); it just had a typo bug in
the verification that prevented it from noticing holes in recovery.
Reviewed By: anand1976
Differential Revision: D25111765
Pulled By: ajkr
fbshipit-source-id: 5e330b13b1ee2b5be096cea9d0ff6075843e57b6
Summary:
Instead of using `EncodeFixed32` which always serialize a integer to
little endian, we should use the local machine's endianness when
populating a native data structure during options parsing.
Without this fix, `read_amp_bytes_per_bit` may be populated incorrectly
on big-endian machines.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7680
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D24999166
Pulled By: riversand963
fbshipit-source-id: dc603cff6e17f8fa32479ce6df93b93082e6b0c4
Summary:
An application may accidentally write merge operands without properly configuring `merge_operator`. We should alert them as early as possible that there's an API misuse. Previously RocksDB only notified them when a query or background operation needed to merge but couldn't. With this PR, RocksDB notifies them of the problem before applying the merge operand to the memtable (although it may already be in WAL, which seems it'd cause a crash loop until they enable `merge_operator`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7667
Reviewed By: riversand963
Differential Revision: D24933360
Pulled By: ajkr
fbshipit-source-id: 3a4a2ceb0b7aed184113dd03b8efd735a8332f7f
Summary:
Added experimental public API for Ribbon filter:
NewExperimentalRibbonFilterPolicy(). This experimental API will
take a "Bloom equivalent" bits per key, and configure the Ribbon
filter for the same FP rate as Bloom would have but ~30% space
savings. (Note: optimize_filters_for_memory is not yet implemented
for Ribbon filter. That can be added with no effect on schema.)
Internally, the Ribbon filter is configured using a "one_in_fp_rate"
value, which is 1 over desired FP rate. For example, use 100 for 1%
FP rate. I'm expecting this will be used in the future for configuring
Bloom-like filters, as I expect people to more commonly hold constant
the filter accuracy and change the space vs. time trade-off, rather than
hold constant the space (per key) and change the accuracy vs. time
trade-off, though we might make that available.
### Benchmarking
```
$ ./filter_bench -impl=2 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 34.1341
Number of filters: 1993
Total size (MB): 238.488
Reported total allocated memory (MB): 262.875
Reported internal fragmentation: 10.2255%
Bits/key stored: 10.0029
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 18.7508
Random filter net ns/op: 258.246
Average FP rate %: 0.968672
----------------------------
Done. (For more info, run with -legend or -help.)
$ ./filter_bench -impl=3 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 130.851
Number of filters: 1993
Total size (MB): 168.166
Reported total allocated memory (MB): 183.211
Reported internal fragmentation: 8.94626%
Bits/key stored: 7.05341
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 58.4523
Random filter net ns/op: 363.717
Average FP rate %: 0.952978
----------------------------
Done. (For more info, run with -legend or -help.)
```
168.166 / 238.488 = 0.705 -> 29.5% space reduction
130.851 / 34.1341 = 3.83x construction time for this Ribbon filter vs. lastest Bloom filter (could make that as little as about 2.5x for less space reduction)
### Working around a hashing "flaw"
bloom_test discovered a flaw in the simple hashing applied in
StandardHasher when num_starts == 1 (num_slots == 128), showing an
excessively high FP rate. The problem is that when many entries, on the
order of number of hash bits or kCoeffBits, are associated with the same
start location, the correlation between the CoeffRow and ResultRow (for
efficiency) can lead to a solution that is "universal," or nearly so, for
entries mapping to that start location. (Normally, variance in start
location breaks the effective association between CoeffRow and
ResultRow; the same value for CoeffRow is effectively different if start
locations are different.) Without kUseSmash and with num_starts > 1 (thus
num_starts ~= num_slots), this flaw should be completely irrelevant. Even
with 10M slots, the chances of a single slot having just 16 (or more)
entries map to it--not enough to cause an FP problem, which would be local
to that slot if it happened--is 1 in millions. This spreadsheet formula
shows that: =1/(10000000*(1 - POISSON(15, 1, TRUE)))
As kUseSmash==false (the setting for Standard128RibbonBitsBuilder) is
intended for CPU efficiency of filters with many more entries/slots than
kCoeffBits, a very reasonable work-around is to disallow num_starts==1
when !kUseSmash, by making the minimum non-zero number of slots
2*kCoeffBits. This is the work-around I've applied. This also means that
the new Ribbon filter schema (Standard128RibbonBitsBuilder) is not
space-efficient for less than a few hundred entries. Because of this, I
have made it fall back on constructing a Bloom filter, under existing
schema, when that is more space efficient for small filters. (We can
change this in the future if we want.)
TODO: better unit tests for this case in ribbon_test, and probably
update StandardHasher for kUseSmash case so that it can scale nicely to
small filters.
### Other related changes
* Add Ribbon filter to stress/crash test
* Add Ribbon filter to filter_bench as -impl=3
* Add option string support, as in "filter_policy=experimental_ribbon:5.678;"
where 5.678 is the Bloom equivalent bits per key.
* Rename internal mode BloomFilterPolicy::kAuto to kAutoBloom
* Add a general BuiltinFilterBitsBuilder::CalculateNumEntry based on
binary searching CalculateSpace (inefficient), so that subclasses
(especially experimental ones) don't have to provide an efficient
implementation inverting CalculateSpace.
* Minor refactor FastLocalBloomBitsBuilder for new base class
XXH3pFilterBitsBuilder shared with new Standard128RibbonBitsBuilder,
which allows the latter to fall back on Bloom construction in some
extreme cases.
* Mostly updated bloom_test for Ribbon filter, though a test like
FullBloomTest::Schema is a next TODO to ensure schema stability
(in case this becomes production-ready schema as it is).
* Add some APIs to ribbon_impl.h for configuring Ribbon filters.
Although these are reasonably covered by bloom_test, TODO more unit
tests in ribbon_test
* Added a "tool" FindOccupancyForSuccessRate to ribbon_test to get data
for constructing the linear approximations in GetNumSlotsFor95PctSuccess.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7658
Test Plan:
Some unit tests updated but other testing is left TODO. This
is considered experimental but laying down schema compatibility as early
as possible in case it proves production-quality. Also tested in
stress/crash test.
Reviewed By: jay-zhuang
Differential Revision: D24899349
Pulled By: pdillinger
fbshipit-source-id: 9715f3e6371c959d923aea8077c9423c7a9f82b8
Summary:
Previously, even when `bottommost_compression_opts`'s `enabled` flag was set, it only took effect when
`bottommost_compression` was also set to something other than `kDisableCompressionOption`.
This wasn't documented and, if we kept the old behavior, it'd make
things complicated like the migration instructions in https://github.com/facebook/rocksdb/issues/7619. We can
simplify the API by making `bottommost_compression_opts` always take
effect when its `enabled` flag is set.
Fixes https://github.com/facebook/rocksdb/issues/7631.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7633
Reviewed By: ltamasi
Differential Revision: D24710358
Pulled By: ajkr
fbshipit-source-id: bbbdf9c1b53c63a4239d902cc3f5a11da1874647
Summary:
The Customizable class is an extension of the Configurable class and allows instances to be created by a name/ID. Classes that extend customizable can define their Type (e.g. "TableFactory", "Cache") and a method to instantiate them (TableFactory::CreateFromString). Customizable objects can be registered with the ObjectRegistry and created dynamically.
Future PRs will make more types of objects extend Customizable.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6590
Reviewed By: cheng-chang
Differential Revision: D24841553
Pulled By: zhichao-cao
fbshipit-source-id: d0c2132bd932e971cbfe2c908ca2e5db30c5e155
Summary:
In `BuildTable()`, we call `builder->Finish()` before evaluating `builder->NeedCompact()`.
However, we call `builder->NeedCompact()` before `builder->Finish()` in compaction job. This can be wrong because the table properties collectors may rely on the success of `Finish()` to provide correct result for `NeedCompact()`.
Test plan (on devserver):
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7627
Reviewed By: ajkr
Differential Revision: D24728741
Pulled By: riversand963
fbshipit-source-id: 5a0dce244e14eb1106c4f87021e6bebca82b486e
Summary:
Existing API `VerifyChecksum()` allows application to verify sst files' block checksums.
Since whole file, user-specified checksum is tracked in MANIFEST, we can expose a new
API to verify sst files' file checksums.
```
// Compute table file checksums if applicable and compare with MANIFEST.
// Returns OK if no file has mismatching whole-file checksum.
Status DB::VerifyFileChecksums(const ReadOptions& /*read_options*/);
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7578
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D24436783
Pulled By: riversand963
fbshipit-source-id: 52b51519b842f2b3c4e3351998a97c86cbec85b3
Summary:
The filter query key should not contain timestamp. The timestamp is
stripped for Get(), but not MultiGet().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7589
Reviewed By: riversand963
Differential Revision: D24494661
Pulled By: jay-zhuang
fbshipit-source-id: fc5ff40f9d683a89a760c6ff0ab3aed05a70c317
Summary:
In dictionary compression's initial implementation, in order to save CPU overhead, we only enabled it
for bottom level under the assumption that the vast majority of data is
stored there. At that time, there was no
such thing as `ColumnFamilyOptions::bottommost_compression_opts`, so we just
hardcoded disabling dictionary compression in flush and compactions to
non-bottommost level. Now, we have users who generate all their files
through flush and are considering using dictionary compression.
To support such a use case, this PR expands the scope of `ColumnFamilyOptions::compression_opts` to
additionally include flushed files and files generated by compaction to
a non-bottommost level. Users can still get the old behavior by moving
their dictionary settings to `ColumnFamilyOptions::bottommost_compression_opts`
and explicitly enabling both that and `ColumnFamilyOptions::bottommost_compression`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7619
Reviewed By: ltamasi
Differential Revision: D24665610
Pulled By: ajkr
fbshipit-source-id: 656b90bce1033fe21c71e09af931ef5bde3e464c
Summary:
The recently reverted behavior changes were released to at least one
place internally, so we should mention the reverts in release notes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7617
Reviewed By: akankshamahajan15
Differential Revision: D24654343
Pulled By: ajkr
fbshipit-source-id: eb64b2797d8508cd95a2dc2698122c1be29ce817
Summary:
Currently, the following interleaving of events can lead to SuperVersion containing both immutable memtables as well as the resulting L0. This can cause Get to return incorrect result if there are merge operands. This may also affect other operations such as single deletes.
```
time main_thr bg_flush_thr bg_compact_thr compact_thr set_opts_thr
0 | WriteManifest:0
1 | issue compact
2 | wait
3 | Merge(counter)
4 | issue flush
5 | wait
6 | WriteManifest:1
7 | wake up
8 | write manifest
9 | wake up
10 | Get(counter)
11 | remove imm
V
```
The reason behind is that: one bg flush thread's installing new `Version` can be batched and performed by another thread that is the "leader" MANIFEST writer. This bg thread removes the memtables from current super version only after `LogAndApply` returns. After the leader MANIFEST writer signals (releasing mutex) this bg flush thread, it is possible that another thread sees this cf with both memtables (whose data have been flushed to the newest L0) and the L0 before this bg flush thread removes the memtables.
To address this issue, each bg flush thread can pass a callback function to `LogAndApply`. The callback is responsible for removing the memtables. Therefore, the leader MANIFEST writer can call this callback and remove the memtables before releasing the mutex.
Test plan (devserver)
```
$make merge_test
$./merge_test --gtest_filter=MergeTest.MergeWithCompactionAndFlush
$make check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6069
Reviewed By: cheng-chang
Differential Revision: D18790894
Pulled By: riversand963
fbshipit-source-id: e41bd600c0448b4f4b2deb3f7677f95e3076b4ed
Summary:
Remove function calling in assert statement as assert is a no
op in opt build and that function might not be called. This causes hang
in closing RocksDB when refit level is set.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7581
Test Plan: make check -j64
Reviewed By: riversand963
Differential Revision: D24466420
Pulled By: akankshamahajan15
fbshipit-source-id: 97db4ec5a95ae693c3290e176a3c12a9b1ad2f6d
Summary:
This PR adds support for writing a location identifier of the DB host to SST files as a table property. By default, the hostname is used, but can be overridden by the user. There have been some recent corruptions in files written by ```SstFileWriter``` before checksumming, so this property can be used to trace it back to the writing host and checking the host for hardware isues.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7479
Test Plan: Add new unit tests
Reviewed By: pdillinger
Differential Revision: D24340671
Pulled By: anand1976
fbshipit-source-id: 2038949fd8d160c0633ccb4f9da77740f19fa2a2
Summary:
These notes existed on the release branches where they were backported, but were never added on master branch. Added them now and mentioned what minor release the fix originally appeared.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7545
Reviewed By: riversand963
Differential Revision: D24281759
Pulled By: ajkr
fbshipit-source-id: 7422e984b667793d6260dd32a7492afcb2ff1c4b
Summary:
The old flag-based APIs (`BlockBasedTableOptions::pin_l0_filter_and_index_blocks_in_cache` and `BlockBasedTableOptions::pin_top_level_index_and_filter`) were insufficient for our needs. For example, it was impossible to pin only unpartitioned meta-blocks, which could prevent block cache contention when turning on dictionary compression or during a migration to partitioned indexes/filters. It was also impossible to pin all meta-blocks in memory while having predictable memory usage via block cache. If we had continued adding flags to address these scenarios, they would have had significant overlap causing confusion. Instead, this PR deprecates the flags and starts a new API with non-overlapping options.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7520
Test Plan:
- new unit test
- added new options to stress/crash test and ran for a while: `$ python tools/db_crashtest.py blackbox --simple --max_key=1000000 -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 --interval=10 -value_size_mult=33 -column_families=1 -reopen=0`
Reviewed By: pdillinger
Differential Revision: D24200034
Pulled By: ajkr
fbshipit-source-id: 3fa7cfc71e7960f7a867511dd6ae5834dd73b13e
Summary:
Add following stats for MultiGet in Histogram to get more insight on MultiGet.
1. Number of index and filter blocks read from file as part of MultiGet
request per level.
2. Number of data blocks read from file per level.
3. Number of SST files loaded from file system per level.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7366
Reviewed By: anand1976
Differential Revision: D24127040
Pulled By: akankshamahajan15
fbshipit-source-id: e63a003056b833729b277edc0639c08fb432756b
Summary:
If `BottommostLevelCompaction.kForce*` is set, compaction should avoid
trivial move and always compact the sst to the target size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7368
Reviewed By: ajkr
Differential Revision: D23629525
Pulled By: jay-zhuang
fbshipit-source-id: 79f23c79ecb31587e0593b28cce43131107bbcd0
Summary:
This exposes to the listener interface whether a compaction was
full or not. Also cleaned up API comment for CompactionJobInfo::stats,
which is not of a nullable type. And since CompactionJob is always
created with non-null CompactionJobStats, removed conditionals on it
being nullptr and instead assert non-null.
TODO later: update C and Java interfaces
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7451
Test Plan: updated existing unit tests to check new field, make check
Reviewed By: ltamasi
Differential Revision: D23977796
Pulled By: pdillinger
fbshipit-source-id: 1ae7e26cb949631c2b2fb9e696710daf53cc378d
Summary:
Introduce an new option options.check_flush_compaction_key_order, by default set to true, which checks key order of flush and compaction, and fail the operation if the order is violated.
Also did minor refactor hash checking code, which consolidates the hashing logic to a vlidation class, where the key ordering logic is added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7467
Test Plan: Add unit tests to validate the check can catch reordering in flush and compaction, and can be properly disabled.
Reviewed By: riversand963
Differential Revision: D24010683
fbshipit-source-id: 8dd6292d2cda8006054e9ded7cfa4bf405f0527c
Summary:
This has been running in production on some key workloads, so
we believe it to be safe and extremely low cost. Nevertheless, I've
added code to ensure that "force_consistency_checks" is mentioned in
any corruption reports so that people know how to disable in case of
false positive corruption reports.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7446
Test Plan:
make check, CI, temporary debug print new message with
./version_builder_test
Reviewed By: ajkr
Differential Revision: D23972101
Pulled By: pdillinger
fbshipit-source-id: 9623e400f3752577c0ecf977e6d0915562cf9968
Summary:
Add a new Option "allow_data_in_errors". When it's set by users, it allows them to opt-in to get error messages containing corrupted keys/values. Corrupt keys, values will be logged in the messages, logs, status etc. that will help users with the useful information regarding affected data.
By default value is set false to prevent users data to be exposed in the messages.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7420
Test Plan:
1. make check -j64
2. Add a new test case
Reviewed By: ajkr
Differential Revision: D23835028
Pulled By: akankshamahajan15
fbshipit-source-id: 8d2eba8fb898e79fcf1fccc07295065a75eb59b1
Summary:
Two relatively simple functional changes to incremental backup
behavior, integrated with a minor refactoring to reduce code redundancy and
improve error/log message. There are nuances to the impact of these changes,
but I believe they are fundamentally good and generally safe. Those functional
changes:
* Incremental backups no longer read DB table files that are already saved to a
shared part of the backup directory, unless `share_files_with_checksum` is used
with `kLegacyCrc32cAndFileSize` naming (discouraged) where crc32c full file
checksums are needed to determine file naming.
* Justification: incremental backups should not need to read the whole DB,
especially without rate limiting. (Although other BackupEngine reads are not
rate limited either, other non-trivial reads are generally limited by a
corresponding write, as in copying files.) Also, the fact that this is not
already fixed was arguably a bug/oversight in the implementation of https://github.com/facebook/rocksdb/issues/7110.
* When considering whether a table file is already backed up in a shared part
of backup directory, BackupEngine would already query the sizes of source (DB)
and pre-existing destination (backup) files. BackupEngine now uses these file
sizes to detect corruption, as at least one of (a) old backup, (b) backup in
progress, or (c) current DB is corrupt if there's a size mismatch.
* Justification: a random related fix that also helps to cover a small hole
in corruption checking uncovered by the other functional change:
* For `share_table_files` without "checksum" (not recommended), the other
change regresses in detecting fundamentally unsafe use of this option
combination: when you might generate different versions of same SST file
number. As demonstrated by `BackupableDBTest.FailOverwritingBackups,` this
regression is greatly mitigated by the new file size checking. Nevertheless,
almost no reason to use `share_files_with_checksum=false` should remain, and
comments are updated appropriately.
Also, this change renames internal function `CalculateChecksum` to
`ReadFileAndComputeChecksum` to make the performance impact of this function
clear in code reviews.
It is not clear what 'same_path' is for in backupable_db.cc, and I suspect it
cannot be true for a DB with unique file names (like DBImpl). Nevertheless,
I've tried to keep its functionality intact when `true` to minimize risk for
now, despite having no unit tests for which it is true.
Select impact details (much more in unit tests): For
`share_files_with_checksum`, I am confident there is no regression (vs.
pre-6.12) in detecting DB or backup corruption at backup creation time, mostly
because the old design did not leverage this extra checksum computation for
detecting inconsistencies at backup creation time. (With computed checksums in
names, a recently corrupted file just looked like a different file vs. what was
already backed up.)
Even in the hypothetical case of DB session id collision (~100 bits entropy
collision), file size in name and/or our file size check add an extra layer of
protection against false success in creating an accurate new backup. (Unit test
included.)
`DB::VerifyChecksum` and `BackupEngine::VerifyBackup` with checksum checking
are still able to catch corruptions that `CreateNewBackup` does not. Note that
when custom file checksum support is added to BackupEngine, that will
essentially give the same power as `DB::VerifyChecksum` into `CreateNewBackup`.
We could add options for `CreateNewBackup` to cover some of what would be
caught by `VerifyBackup` with checksum checking.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7413
Test Plan:
Two new unit tests included, both of which fail without these
changes. Although we don't test the I/O improvement directly, we test it
indirectly in DB corruption detection power that was inadvertently unlocked
with new backup file naming PLUS computing current content checksums (now
removed). (I don't think that case of DB corruption detection justifies reading
the whole DB on incremental backup.)
Reviewed By: zhichao-cao
Differential Revision: D23818480
Pulled By: pdillinger
fbshipit-source-id: 148aff16f001af5b9fd4b22f155311c2461f1bac
Summary:
This change reverts BackupEngine to 6.12 state to accommodate a
higher-priority fix that does not easily merge with this custom checksum
support. We intend to reinstate this support soon, by merging a revert
of this change.
For backupable_db_test, I've removed the tests depending on this
feature.
I've also removed relevant HISTORY.md entry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7411
Test Plan: unit tests
Reviewed By: ajkr
Differential Revision: D23793835
Pulled By: pdillinger
fbshipit-source-id: 7e861436539584799b13d1a8ae559b81b6d08052
Summary:
In the current implementation, any retryable IO error happens during Flush is mapped to a hard error. In this case, DB is stopped and write is stalled unless the background error is cleaned. In this PR, if WAL is DISABLED, the retryable IO error during FLush is mapped to a soft error. Such that, the memtable can continue receive the writes. At the same time, if auto resume is triggered, SwtichMemtable will not be called during Flush when resuming the DB to avoid to many small memtables. Testing cases are added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7310
Test Plan: adding new unit test, pass make check.
Reviewed By: anand1976
Differential Revision: D23710892
Pulled By: zhichao-cao
fbshipit-source-id: bc4ca50d11c6b23b60d2c0cb171d86d542b038e9
Summary:
Prior to 6.12, backup files using share_files_with_checksum had
the file size encoded in the file name, after the last '\_' and before
the last '.'. We considered this an implementation detail subject to
change, and indeed removed this information from the file name (with an
option to use old behavior) because it was considered
ineffective/inefficient for file name uniqueness. However, some
downstream RocksDB users were relying on this information since the file
size is not explicitly in the backup manifest file.
This primary purpose of this change is "retrofitting" the 6.12 release
(not yet a public release) to simultaneously support the benefits of the
new naming scheme (I/O performance and data correctness at scale) and
preserve the file size information, both as default behaviors. With this
change, we are essentially making the file size information encoded in
the file name an official, though obscure, extension of the backup meta
file format.
We preserve an option (kLegacyCrc32cAndFileSize) to use the original
"legacy" naming scheme, with its caveats, and make it easy to omit the
file size information (no kFlagIncludeFileSize), for more compact file
names. But note that changing the naming scheme used on an existing db
and backup directory can lead to transient space amplification, as some
files will be stored under two names in the shared_checksum directory.
Because some backups were saved using the original 6.12 naming scheme,
we offer two ways of dealing with those files: SST files generated by
older 6.12 versions can either use the default naming scheme in effect
when the SST files were generated (kFlagMatchInterimNaming, default, no
transient space amplification) or can use a new naming scheme (no
kFlagMatchInterimNaming, potential space amplification because some
already stored files getting a new name).
We don't have a natural way to detect which files were generated by
previous 6.12 versions, but this change hacks one in by changing DB
session ids to now use a more concise encoding, reducing file name
length, saving ~dozen bytes from SST files, and making them visually
distinct from DB ids so that they are less likely to be mixed up.
Two final auxiliary notes:
Recognizing that the backup file names have become a de facto part of
the backup meta schema, this change makes them easier to parse and
extend by putting a distinct marker, 's', before DB session ids embedded
in the name. When we extend this to allow custom checksums in the name,
they can get their own marker to ensure safe parsing. For backward
compatibility, file size does not get a marker but is assumed for
`_[0-9]+[.]`
Another change from initial 6.12 default behavior is never including
file custom checksum in the file name. Looking ahead to 6.13, we do not
want the default behavior to cause backup space amplification for
someone turning on file custom checksum checking in BackupEngine; we
want that to be an easy decision. When implemented, including file
custom checksums in backup file names will be a non-default option.
Actual file name patterns and priorities, as regexes:
kLegacyCrc32cAndFileSize OR pre-6.12 SST file ->
[0-9]+_[0-9]+_[0-9]+[.]sst
kFlagMatchInterimNaming set (default) AND early 6.12 SST file ->
[0-9]+_[0-9a-fA-F-]+[.]sst
kUseDbSessionId AND NOT kFlagIncludeFileSize ->
[0-9]+_s[0-9A-Z]{20}[.]sst
kUseDbSessionId AND kFlagIncludeFileSize (default) ->
[0-9]+_s[0-9A-Z]{20}_[0-9]+[.]sst
We might add opt-in options for more '\_' separated data in the name,
but embedded file size, if present, will always be after last '\_' and
before '.sst'.
This change was originally applied to version 6.12. (See https://github.com/facebook/rocksdb/issues/7390)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7400
Test Plan:
unit tests included. Sync point callbacks are used to mimic
previous version SST files.
Reviewed By: ajkr
Differential Revision: D23759587
Pulled By: pdillinger
fbshipit-source-id: f62d8af4e0978de0a34f26288cfbe66049b70025
Adam Retter