Commit Graph

102 Commits

Author SHA1 Message Date
Yu Zhang 7521478b43 Record the `persist_user_defined_timestamps` flag in manifest (#11515)
Summary:
Start to record the value of the flag `AdvancedColumnFamilyOptions.persist_user_defined_timestamps` in the Manifest and table properties for a SST file when it is created. And use the recorded flag when creating a table reader for the SST file. This flag's default value is true, it is only explicitly recorded if it's false.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11515

Test Plan:
```
make all check
./version_edit_test
```

Reviewed By: ltamasi

Differential Revision: D46920386

Pulled By: jowlyzhang

fbshipit-source-id: 075c20363d3d2cc1368422ecc805617ed135cc26
2023-06-21 21:49:01 -07:00
Hui Xiao 8f763bdeab Record and use the tail size to prefetch table tail (#11406)
Summary:
**Context:**
We prefetch the tail part of a SST file (i.e, the blocks after data blocks till the end of the file) during each SST file open in hope to prefetch all the stuff at once ahead of time for later read e.g, footer, meta index, filter/index etc. The existing approach to estimate the tail size to prefetch is through `TailPrefetchStats` heuristics introduced in https://github.com/facebook/rocksdb/pull/4156, which has caused small reads in unlucky case (e.g,  small read into the tail buffer during table open in thread 1 under the same BlockBasedTableFactory object can make thread 2's tail prefetching use a small size that it shouldn't) and is hard to debug.  Therefore we decide to record the exact tail size and use it directly  to prefetch tail of the SST instead of relying heuristics.

**Summary:**
- Obtain and record in manifest the tail size in `BlockBasedTableBuilder::Finish()`
   - For backward compatibility, we fall back to TailPrefetchStats and last to simple heuristics that the tail size is a linear portion of the file size - see PR conversation for more.
- Make`tail_start_offset` part of the table properties and deduct tail size to record in manifest for external files (e.g, file ingestion, import CF) and db repair (with no access to manifest).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11406

Test Plan:
1. New UT
2. db bench
Note: db bench on /tmp/ where direct read is supported is too slow to finish and the default pinning setting in db bench is not helpful to profile # sst read of Get. Therefore I hacked the following to obtain the following comparison.
```
 diff --git a/table/block_based/block_based_table_reader.cc b/table/block_based/block_based_table_reader.cc
index bd5669f0f..791484c1f 100644
 --- a/table/block_based/block_based_table_reader.cc
+++ b/table/block_based/block_based_table_reader.cc
@@ -838,7 +838,7 @@ Status BlockBasedTable::PrefetchTail(
                            &tail_prefetch_size);

   // Try file system prefetch
-  if (!file->use_direct_io() && !force_direct_prefetch) {
+  if (false && !file->use_direct_io() && !force_direct_prefetch) {
     if (!file->Prefetch(prefetch_off, prefetch_len, ro.rate_limiter_priority)
              .IsNotSupported()) {
       prefetch_buffer->reset(new FilePrefetchBuffer(
 diff --git a/tools/db_bench_tool.cc b/tools/db_bench_tool.cc
index ea40f5fa0..39a0ac385 100644
 --- a/tools/db_bench_tool.cc
+++ b/tools/db_bench_tool.cc
@@ -4191,6 +4191,8 @@ class Benchmark {
           std::shared_ptr<TableFactory>(NewCuckooTableFactory(table_options));
     } else {
       BlockBasedTableOptions block_based_options;
+      block_based_options.metadata_cache_options.partition_pinning =
+      PinningTier::kAll;
       block_based_options.checksum =
           static_cast<ChecksumType>(FLAGS_checksum_type);
       if (FLAGS_use_hash_search) {
```
Create DB
```
./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none
```
ReadRandom
```
./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none
```
(a) Existing (Use TailPrefetchStats for tail size + use seperate prefetch buffer in PartitionedFilter/IndexReader::CacheDependencies())
```
rocksdb.table.open.prefetch.tail.hit COUNT : 3395
rocksdb.sst.read.micros P50 : 5.655570 P95 : 9.931396 P99 : 14.845454 P100 : 585.000000 COUNT : 999905 SUM : 6590614
```

(b) This PR (Record tail size + use the same tail buffer in PartitionedFilter/IndexReader::CacheDependencies())
```
rocksdb.table.open.prefetch.tail.hit COUNT : 14257
rocksdb.sst.read.micros P50 : 5.173347 P95 : 9.015017 P99 : 12.912610 P100 : 228.000000 COUNT : 998547 SUM : 5976540
```

As we can see, we increase the prefetch tail hit count and decrease SST read count with this PR

3. Test backward compatibility by stepping through reading with post-PR code on a db generated pre-PR.

Reviewed By: pdillinger

Differential Revision: D45413346

Pulled By: hx235

fbshipit-source-id: 7d5e36a60a72477218f79905168d688452a4c064
2023-05-08 13:14:28 -07:00
Hui Xiao 151242ce46 Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288)
Summary:
**Context:**
The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them.

**Summary**
- Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros`
   - Fixed the default histogram in `RandomAccessFileReader`
- New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader`
- Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288

Test Plan:
- **Stress test**
- **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.**  (without blob)
     - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads.
```
./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10)
```
```
// BlockBasedTable
rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805
rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116
rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689

// PlainTable
Does not apply
```
- **Db bench 2: performance**

**Read**

SETUP: db with 900 files
```
./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655  -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none
```run till convergence
```
./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3
```
Pre-change
`readrandom [AVG 60 runs] : 21568 (± 248) ops/sec`
Post-change (no regression, -0.3%)
`readrandom [AVG 60 runs] : 21486 (± 236) ops/sec`

**Compaction/Flush**run till convergence
```
./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655  -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none

rocksdb.sst.read.micros  COUNT : 33820
rocksdb.sst.read.flush.micros COUNT : 1800
rocksdb.sst.read.compaction.micros COUNT : 32020
```
Pre-change
`fillseq [AVG 46 runs] : 1391 (± 214) ops/sec;    0.7 (± 0.1) MB/sec`

Post-change (no regression, ~-0.4%)
`fillseq [AVG 46 runs] : 1385 (± 216) ops/sec;    0.7 (± 0.1) MB/sec`

Reviewed By: ajkr

Differential Revision: D44007011

Pulled By: hx235

fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 09:07:18 -07:00
Peter Dillinger 433d7e4594 Improve error messages for SST footer and size errors (#11009)
Summary:
Previously, you could get a format_version error if SST file size was too small in manifest, or a weird "too short" error if too big in manifest. Now we ensure:
* Magic number error is reported first if we attempt to open an SST file and the footer is completely bad.
* Footer errors are reported with affected file.
* If manifest file size doesn't match actual, then the error includes expected and actual sizes (if an error is reported; in some cases we allow the file to be too big)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11009

Test Plan:
unit tests added, some manual

Previously, the code for "file too short" in footer processing was only covered by some tests attempting to verify SST checksums on non-SST files (fixed).

Reviewed By: siying

Differential Revision: D41656272

Pulled By: pdillinger

fbshipit-source-id: 3da32702eb5aaedbea0e5e74742ad57edd7ad3df
2022-12-09 10:03:47 -08:00
anand76 727bad78b8 Format files under table/ by clang-format (#10852)
Summary:
Run clang-format on files under the `table` directory.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10852

Reviewed By: ajkr

Differential Revision: D40650732

Pulled By: anand1976

fbshipit-source-id: 2023a958e37fd6274040c5181130284600c9e0ef
2022-10-25 11:50:38 -07:00
Peter Dillinger ef443cead4 Refactor to avoid confusing "raw block" (#10408)
Summary:
We have a lot of confusing code because of mixed, sometimes
completely opposite uses of of the term "raw block" or "raw contents",
sometimes within the same source file. For example, in `BlockBasedTableBuilder`,
`raw_block_contents` and `raw_size` generally referred to uncompressed block
contents and size, while `WriteRawBlock` referred to writing a block that
is already compressed if it is going to be. Meanwhile, in
`BlockBasedTable`, `raw_block_contents` either referred to a (maybe
compressed) block with trailer, or a maybe compressed block maybe
without trailer. (Note: left as follow-up work to use C++ typing to
better sort out the various kinds of BlockContents.)

This change primarily tries to apply some consistent terminology around
the kinds of block representations, avoiding the unclear "raw". (Any
meaning of "raw" assumes some bias toward the storage layer or toward
the logical data layer.) Preferred terminology:

* **Serialized block** - bytes that go into storage. For block-based table
(usually the case) this includes the block trailer. WART: block `size` may or
may not include the trailer; need to be clear about whether it does or not.
* **Maybe compressed block** - like a serialized block, but without the
trailer (or no promise of including a trailer). Must be accompanied by a
CompressionType.
* **Uncompressed block** - "payload" bytes that are either stored with no
compression, used as input to compression function, or result of
decompression function.
* **Parsed block** - an in-memory form of a block in block cache, as it is
used by the table reader. Different C++ types are used depending on the
block type (see block_like_traits.h).

Other refactorings:
* Misc corrections/improvements of internal API comments
* Remove a few misleading / unhelpful / redundant comments.
* Use move semantics in some places to simplify contracts
* Use better parameter names to indicate which parameters are used for
outputs
* Remove some extraneous `extern`
* Various clean-ups to `CacheDumperImpl` (mostly unnecessary code)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10408

Test Plan: existing tests

Reviewed By: akankshamahajan15

Differential Revision: D38172617

Pulled By: pdillinger

fbshipit-source-id: ccb99299f324ac5ca46996d34c5089621a4f260c
2022-09-22 11:25:32 -07:00
Jay Zhuang a3acf2ef87 Add seqno to time mapping (#10338)
Summary:
Which will be used for tiered storage to preclude hot data from
compacting to the cold tier (the last level).
Internally, adding seqno to time mapping. A periodic_task is scheduled
to record the current_seqno -> current_time in certain cadence. When
memtable flush, the mapping informaiton is stored in sstable property.
During compaction, the mapping information are merged and get the
approximate time of sequence number, which is used to determine if a key
is recently inserted or not and preclude it from the last level if it's
recently inserted (within the `preclude_last_level_data_seconds`).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338

Test Plan: CI

Reviewed By: siying

Differential Revision: D37810187

Pulled By: jay-zhuang

fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f
2022-07-14 21:49:34 -07:00
sdong 49628c9a83 Use std::numeric_limits<> (#9954)
Summary:
Right now we still don't fully use std::numeric_limits but use a macro, mainly for supporting VS 2013. Right now we only support VS 2017 and up so it is not a problem. The code comment claims that MinGW still needs it. We don't have a CI running MinGW so it's hard to validate. since we now require C++17, it's hard to imagine MinGW would still build RocksDB but doesn't support std::numeric_limits<>.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9954

Test Plan: See CI Runs.

Reviewed By: riversand963

Differential Revision: D36173954

fbshipit-source-id: a35a73af17cdcae20e258cdef57fcf29a50b49e0
2022-05-05 13:08:21 -07:00
Peter Dillinger 8ce7cea93f Tests for filter compatibility (#9773)
Summary:
This change adds two unit tests that would each catch the
regression fixed in https://github.com/facebook/rocksdb/issues/9736

* TableMetaIndexKeys - detects any churn in metaindex block keys
generated by SST files using standard db_test_util configurations.
* BloomFilterCompatibility - this detects if any common built-in
FilterPolicy configurations fail to read filters generated by another.
(The regression bug caused NewRibbonFilterPolicy not to read filters
from NewBloomFilterPolicy and vice-versa.) This replaces some previous
tests that didn't really appear to be testing much of anything except
basic data correctness, which doesn't tell you a filter is being used.

Light refactoring in meta_blocks.cc/h to support inspecting metaindex
keys.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9773

Test Plan:
this is the test. Verified that 7.0.2 fails both tests and 7.0.3 passes.
With backporting for intentional API changes in 7.0, 6.29 also passes.

Reviewed By: ajkr

Differential Revision: D35236248

Pulled By: pdillinger

fbshipit-source-id: 493dfe9ad7e27524bf7c6c1af8a4b8c31bc6ef5a
2022-04-06 15:54:40 -07:00
mrambacher 9a116ab4b4 Add NewMetaDataIterator method (#8692)
Summary:
Fixes a problem where the iterator for metadata was being treated as a non-user key when in fact it was a user key.  This led to a problem where the property keys could not be searched for correctly.

The main exposure of this problem was that the HashIndexReader could not get the "prefixes" property correctly, resulting in the failure of retrieval/creation of the BlockPrefixIndex.

Added BlockBasedTableTest.SeekMetaBlocks test to validate this condition.

Fixing this condition exposed two other tests (SeekWithPrefixLongerThanKey, MultiGetPrefixFilter) that passed incorrectly previously and now failed.  Updated those two tests to pass.  Not sure if the tests are functionally correct/still appropriate, but made them pass...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8692

Reviewed By: riversand963

Differential Revision: D33119539

Pulled By: mrambacher

fbshipit-source-id: 658969fe9265f73dc184dab97cc3f4eaed2d881a
2021-12-21 11:32:49 -08:00
Peter Dillinger 653c392e47 More refactoring ahead of footer & meta changes (#9240)
Summary:
I'm working on a new format_version=6 to support context
checksum (https://github.com/facebook/rocksdb/issues/9058) and this includes much of the refactoring and test
updates to support that change.

Test coverage data and manual inspection agree on dead code in
block_based_table_reader.cc (removed).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9240

Test Plan:
tests enhanced to cover more cases etc.

Extreme case performance testing indicates small % regression in fillseq (w/ compaction), though CPU profile etc. doesn't suggest any explanation. There is enhanced correctness checking in Footer::DecodeFrom, but this should be negligible.

TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=30000000 -checksum_type=1 --disable_wal={false,true}

(Each is ops/s averaged over 50 runs, run simultaneously with competing configuration for load fairness)
Before w/ wal: 454512
After w/ wal: 444820 (-2.1%)
Before w/o wal: 1004560
After w/o wal: 998897 (-0.6%)

Since this doesn't modify WAL code, one would expect real effects to be larger in w/o wal case.

This regression will be corrected in a follow-up PR.

Reviewed By: ajkr

Differential Revision: D32813769

Pulled By: pdillinger

fbshipit-source-id: 444a244eabf3825cd329b7d1b150cddce320862f
2021-12-10 08:13:26 -08:00
Hui Xiao 9daf07305c Replace TableProperties::properties_offsets map with external_sst_file_global_seqno_offset (#9212)
Summary:
**Context:**
Searching `TableProperties::properties_offsets` across the codebase reveals that internally it is only used to find the external SST file's global seqno offeset. Therefore we can narrow it down and replace this map property with a uint64_t property `external_sst_file_global_seqno_offset` to save memory usage related to table properties.

Note:
- See PR comments for discussion about potential impact on existing external usage of `TableProperties::properties_offsets`
- See PR comments for discussion on keeping external SST file global seqno's offset VS using a simple flag indicating seqno's existence.

**Summary:**
- Replaced `TableProperties::properties_offsets` with `TableProperties::external_sst_file_global_seqno_offset`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9212

Test Plan: - Relied on existing tests should be sufficient since `TableProperties::properties_offsets` existed before and should already be tested.

Reviewed By: ajkr

Differential Revision: D32665941

Pulled By: hx235

fbshipit-source-id: 718e44617346dc4f3b1276ee953e61c196277795
2021-12-02 08:30:36 -08:00
Peter Dillinger cd4ea675e3 Fix backward compatibility with 2.5 through 2.7 (#9189)
Summary:
A bug in https://github.com/facebook/rocksdb/issues/9163 can cause checksum verification to fail if
parsing a properties block fails.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9189

Test Plan:
check_format_compatible.sh (never quite works locally but
this particular case seems fixed using variants of SHORT_TEST=1).
And added new unit test case.

Reviewed By: ajkr

Differential Revision: D32574626

Pulled By: pdillinger

fbshipit-source-id: 6fa5c8595737b71a3c3d011a52daf6d6c08715d7
2021-11-19 17:31:01 -08:00
Peter Dillinger 230660be73 Improve / clean up meta block code & integrity (#9163)
Summary:
* Checksums are now checked on meta blocks unless specifically
suppressed or not applicable (e.g. plain table). (Was other way around.)
This means a number of cases that were not checking checksums now are,
including direct read TableProperties in Version::GetTableProperties
(fixed in meta_blocks ReadTableProperties), reading any block from
PersistentCache (fixed in BlockFetcher), read TableProperties in
SstFileDumper (ldb/sst_dump/BackupEngine) before table reader open,
maybe more.
* For that to work, I moved the global_seqno+TableProperties checksum
logic to the shared table/ code, because that is used by many utilies
such as SstFileDumper.
* Also for that to work, we have to know when we're dealing with a block
that has a checksum (trailer), so added that capability to Footer based
on magic number, and from there BlockFetcher.
* Knowledge of trailer presence has also fixed a problem where other
table formats were reading blocks including bytes for a non-existant
trailer--and awkwardly kind-of not using them, e.g. no shared code
checking checksums. (BlockFetcher compression type was populated
incorrectly.) Now we only read what is needed.
* Minimized code duplication and differing/incompatible/awkward
abstractions in meta_blocks.{cc,h} (e.g. SeekTo in metaindex block
without parsing block handle)
* Moved some meta block handling code from table_properties*.*
* Moved some code specific to block-based table from shared table/ code
to BlockBasedTable class. The checksum stuff means we can't completely
separate it, but things that don't need to be in shared table/ code
should not be.
* Use unique_ptr rather than raw ptr in more places. (Note: you can
std::move from unique_ptr to shared_ptr.)

Without enhancements to GetPropertiesOfAllTablesTest (see below),
net reduction of roughly 100 lines of code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9163

Test Plan:
existing tests and
* Enhanced DBTablePropertiesTest.GetPropertiesOfAllTablesTest to verify that
checksums are now checked on direct read of table properties by TableCache
(new test would fail before this change)
* Also enhanced DBTablePropertiesTest.GetPropertiesOfAllTablesTest to test
putting table properties under old meta name
* Also generally enhanced that same test to actually test what it was
supposed to be testing already, by kicking things out of table cache when
we don't want them there.

Reviewed By: ajkr, mrambacher

Differential Revision: D32514757

Pulled By: pdillinger

fbshipit-source-id: 507964b9311d186ae8d1131182290cbd97a99fa9
2021-11-18 11:43:44 -08:00
mrambacher 13ae16c315 Cleanup includes in dbformat.h (#8930)
Summary:
This header file was including everything and the kitchen sink when it did not need to.  This resulted in many places including this header when they needed other pieces instead.

Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing.

Hopefully, this sort of code hygiene cleanup will speed up the builds...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930

Reviewed By: pdillinger

Differential Revision: D31142788

Pulled By: mrambacher

fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d
2021-09-29 04:04:40 -07:00
Peter Dillinger 04db764831 Embed original file number in SST table properties (#8686)
Summary:
I very recently realized that with https://github.com/facebook/rocksdb/issues/8669 we cannot later add
file numbers to external SST files (so that more can share db session
ids for better uniqueness properties), because of forward compatibility.
We would have a version of RocksDB that assumes session IDs are unique
on external SST files and therefore can't really break that invariant in
future files.

This change adds a table property for "orig_file_number" which is
populated by normal SST files and also external SST files generated by
SstFileWriter. SstFileWriter now keeps a db_session_id for life of the
object and increments its own file numbers for embedding in table
properties. (They are arguably "fake" file numbers because these numbers
and not embedded in the file name.)

While updating block_based_table_builder, I removed several unnecessary
fields from Rep, because following the pattern would have created
another unnecessary field.

This change also updates block_based_table_reader to use this new
property when available, which means that for newer SST files, we can
determine the stable/original <db_session_id,file_number> unique
identifier using just the file contents, not the file name. (It's a bit
complicated; detailed comments in block_based_table_reader.)

Also added DB host id to properties listing by sst_dump, which could be
useful in debugging.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8686

Test Plan: majorly overhauled StableCacheKeys test for this change

Reviewed By: zhichao-cao

Differential Revision: D30457742

Pulled By: pdillinger

fbshipit-source-id: 2e5ae7dddeb94fb9d8eac8a928486aed8b8cd445
2021-08-20 20:40:48 -07:00
Peter Dillinger a207c27809 Stable cache keys using DB session ids in SSTs (#8659)
Summary:
Use DB session ids in SST table properties to make cache keys
stable across DB re-open and copy / move / restore / etc.

These new cache keys are currently only enabled when FileSystem does not
provide GetUniqueId. For now, they are typically larger, so slightly
less efficient.

Relevant to https://github.com/facebook/rocksdb/issues/7405

This change has a minor regression in PersistentCache functionality:
metaindex blocks are no longer cached in PersistentCache. Table properties
blocks already were not but ideally should be. I didn't spent effort to
fix & test these issues because we don't believe PersistentCache is used much
if at all and expect SecondaryCache to replace it. (Though PRs are welcome.)

FIXME: there is more to be fixed for stable cache keys on external SST files

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8659

Test Plan:
new unit test added, which fails when disabling new
functionality

Reviewed By: zhichao-cao

Differential Revision: D30297705

Pulled By: pdillinger

fbshipit-source-id: e8539a5c8802a79340405629870f2e3fb3822d3a
2021-08-16 20:37:20 -07:00
Peter Dillinger 3469d60fcc Add table properties for number of entries added to filters (#8323)
Summary:
With Ribbon filter work and possible variance in actual bits
per key (or prefix; general term "entry") to achieve certain FP rates,
I've received a request to be able to track actual bits per key in
generated filters. This change adds a num_filter_entries table
property, which can be combined with filter_size to get bits per key
(entry).

This can vary from num_entries in at least these ways:
* Different versions of same key are only counted once in filters.
* With prefix filters, several user keys map to the same filter entry.
* A single filter can include both prefixes and user keys.

Note that FilterBlockBuilder::NumAdded() didn't do anything useful
except distinguish empty from non-empty.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8323

Test Plan: basic unit test included, others updated

Reviewed By: jay-zhuang

Differential Revision: D28596210

Pulled By: pdillinger

fbshipit-source-id: 529a111f3c84501e5a470bc84705e436ee68c376
2021-05-21 17:11:32 -07:00
mrambacher 8948dc8524 Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262)
Summary:
The ImmutableCFOptions contained a bunch of fields that belonged to the ImmutableDBOptions.  This change cleans that up by introducing an ImmutableOptions struct.  Following the pattern of Options struct, this class inherits from the DB and CFOption structs (of the Immutable form).

Only one structural change (the ImmutableCFOptions::fs was changed to a shared_ptr from a raw one) is in this PR.  All of the other changes involve moving the member variables from the ImmutableCFOptions into the ImmutableOptions and changing member variables or function parameters as required for compilation purposes.

Follow-on PRs may do a further clean-up of the code, such as renaming variables (such as "ImmutableOptions cf_options") and potentially eliminating un-needed function parameters (there is no longer a need to pass both an ImmutableDBOptions and an ImmutableOptions to a function).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8262

Reviewed By: pdillinger

Differential Revision: D28226540

Pulled By: mrambacher

fbshipit-source-id: 18ae71eadc879dedbe38b1eb8e6f9ff5c7147dbf
2021-05-05 14:00:17 -07:00
mrambacher 0ca6d6297f Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)
Summary:
Renaming ImmutableCFOptions::info_log and statistics to logger and stats.  This is stage 2 in creating an ImmutableOptions class.  It is necessary because the names match those in ImmutableOptions and have different types.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8227

Reviewed By: jay-zhuang

Differential Revision: D28000967

Pulled By: mrambacher

fbshipit-source-id: 3bf2aa04e8f1e8724d825b7deacf41080c14420b
2021-04-26 12:43:45 -07:00
mrambacher 01e460d538 Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176)
Summary:
This PR is a first step at attempting to clean up some of the Mutable/Immutable Options code.  With this change, a DBOption and a ColumnFamilyOption can be reconstructed from their Mutable and Immutable equivalents, respectively.

readrandom tests do not show any performance degradation versus master (though both are slightly slower than the current 6.19 release).

There are still fields in the ImmutableCFOptions that are not CF options but DB options.  Eventually, I would like to move those into an ImmutableOptions (= ImmutableDBOptions+ImmutableCFOptions).  But that will be part of a future PR to minimize changes and disruptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8176

Reviewed By: pdillinger

Differential Revision: D27954339

Pulled By: mrambacher

fbshipit-source-id: ec6b805ba9afe6e094bffdbd76246c2d99aa9fad
2021-04-22 20:43:54 -07:00
Andrew Kryczka 1ba2b8a568 Add sample_for_compression results to table properties (#8139)
Summary:
Added `TableProperties::{fast,slow}_compression_estimated_data_size`.
These properties are present in block-based tables when
`ColumnFamilyOptions::sample_for_compression > 0` and the necessary
compression library is supported when the file is generated. They
contain estimates of what `TableProperties::data_size` would be if the
"fast"/"slow" compression library had been used instead. One
limitation is we do not record exactly which "fast" (ZSTD or Zlib)
or "slow" (LZ4 or Snappy) compression library produced the result.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8139

Test Plan:
- new unit test
- ran `db_bench` with `sample_for_compression=1`; verified the `data_size` property matches the `{slow,fast}_compression_estimated_data_size` when the same compression type is used for the output file compression and the sampled compression

Reviewed By: riversand963

Differential Revision: D27454338

Pulled By: ajkr

fbshipit-source-id: 9529293de93ddac7f03b2e149d746e9f634abac4
2021-03-31 18:21:50 -07:00
Andrew Kryczka c20a7cd6c7 Apply `sample_for_compression` to all block-based tables (#8105)
Summary:
Previously it only applied to block-based tables generated by flush. This restriction
was undocumented and blocked a new use case. Now compression sampling
applies to all block-based tables we generate when it is enabled.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8105

Test Plan: new unit test

Reviewed By: riversand963

Differential Revision: D27317275

Pulled By: ajkr

fbshipit-source-id: cd9fcc5178d6515e8cb59c6facb5ac01893cb5b0
2021-03-25 15:00:45 -07:00
anand76 00751e4292 Add a host location property to TableProperties (#7479)
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
2020-10-19 11:38:48 -07:00
Peter Dillinger 93719fc953 Restore file size in backup table file names (and other cleanup) (#7400)
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
2020-09-17 10:24:22 -07:00
Andrew Kryczka dd29ad4223 Separate internal and user key comparators in `BlockIter` (#6944)
Summary:
Replace `BlockIter::comparator_` and `IndexBlockIter::user_comparator_wrapper_` with a concrete `UserComparatorWrapper` and `InternalKeyComparator`. The motivation for this change was the inconvenience of not knowing the concrete type of `BlockIter::comparator_`, which prevented calling specialized internal key comparison functions to optimize comparison of keys with global seqno applied.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/6944

Test Plan:
benchmark setup -- single file DBs, in-memory, no compression. "normal_db"
created by regular flush; "ingestion_db" created by ingesting a file. Both
DBs have same contents.

```
$ TEST_TMPDIR=/dev/shm/normal_db/ ./db_bench -benchmarks=fillrandom,compact -write_buffer_size=10485760000 -disable_auto_compactions=true -compression_type=none -num=1000000
$ ./ldb write_extern_sst ./tmp.sst --db=/dev/shm/ingestion_db/dbbench/ --compression_type=no --hex --create_if_missing < <(./sst_dump --command=scan --output_hex --file=/dev/shm/normal_db/dbbench/000007.sst | awk 'began {print "0x" substr($1, 2, length($1) - 2), "==>", "0x" $5} ; /^Sst file format: block-based/ {began=1}')
$ ./ldb ingest_extern_sst ./tmp.sst --db=/dev/shm/ingestion_db/dbbench/
```

benchmark run command:

```
$ TEST_TMPDIR=/dev/shm/$DB/ ./db_bench -benchmarks=seekrandom -seek_nexts=$SEEK_NEXT -use_existing_db=true -cache_index_and_filter_blocks=false -num=1000000 -cache_size=0 -threads=1 -reads=200000000 -mmap_read=1 -verify_checksum=false
```

results: perf improved marginally for ingestion_db and did not change significantly for normal_db:

SEEK_NEXT | DB | code | ops/sec | % change
-- | -- | -- | -- | --
0 | normal_db | master | 350880 |  
0 | normal_db | PR6944 | 351040 | 0.0
0 | ingestion_db | master | 343255 |  
0 | ingestion_db | PR6944 | 349424 | 1.8
10 | normal_db | master | 218711 |  
10 | normal_db | PR6944 | 217892 | -0.4
10 | ingestion_db | master | 220334 |  
10 | ingestion_db | PR6944 | 226437 | 2.8

Reviewed By: pdillinger

Differential Revision: D21924676

Pulled By: ajkr

fbshipit-source-id: ea4288a2eefa8112eb6c651a671c1de18c12e538
2020-07-07 17:26:16 -07:00
Anand Ananthabhotla 9a5886bd8c Extend Get/MultiGet deadline support to table open (#6982)
Summary:
Current implementation of the ```read_options.deadline``` option only checks the deadline for random file reads during point lookups. This PR extends the checks to file opens, prefetches and preloads as part of table open.

The main changes are in the ```BlockBasedTable```, partitioned index and filter readers, and ```TableCache``` to take ReadOptions as an additional parameter. In ```BlockBasedTable::Open```, in order to retain existing behavior w.r.t checksum verification and block cache usage, we filter out most of the options in ```ReadOptions``` except ```deadline```. However, having the ```ReadOptions``` gives us more flexibility to honor other options like verify_checksums, fill_cache etc. in the future.

Additional changes in callsites due to function signature changes in ```NewTableReader()``` and ```FilePrefetchBuffer```.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6982

Test Plan: Add new unit tests in db_basic_test

Reviewed By: riversand963

Differential Revision: D22219515

Pulled By: anand1976

fbshipit-source-id: 8a3b92f4a889808013838603aa3ca35229cd501b
2020-06-29 14:53:17 -07:00
Zitan Chen 94d04529de Store DB identity and DB session ID in SST files (#6983)
Summary:
`db_id` and `db_session_id` are now part of the table properties for all formats and stored in SST files. This adds about 99 bytes to each new SST file.

The `TablePropertiesNames` for these two identifiers are `rocksdb.creating.db.identity` and `rocksdb.creating.session.identity`.

In addition, SST files generated from SstFileWriter and Repairer have DB identity “SST Writer” and “DB Repairer”, respectively. Their DB session IDs are generated in the same way as `DB::GetDbSessionId`.

A table property test is added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6983

Test Plan: make check and some manual tests.

Reviewed By: zhichao-cao

Differential Revision: D22048826

Pulled By: gg814

fbshipit-source-id: afdf8c11424a6f509b5c0b06dafad584a80103c9
2020-06-17 10:57:40 -07:00
sdong 4a4b8a1344 sst_dump to reduce number of file reads (#6836)
Summary:
sst_dump can issue many file reads from the file system. This doesn't work well with file systems without a OS cache, especially remote file systems. In order to mitigate this problem, several improvements are done:
1. --readahead_size is added, so that users can specify readahead size when scanning the data.
2. Force a 512KB tail readahead, which prevents three I/Os for footer, meta index and property blocks and hopefully index and filter blocks too.
3. Consoldiate SSTDump's I/Os before opening the file for read. Use the same file prefetch buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6836

Test Plan: Add a test that covers this new feature.

Reviewed By: pdillinger

Differential Revision: D21516607

fbshipit-source-id: 3ae43526286f67b2f4a5bdedfbc92719d579b87e
2020-05-12 18:23:33 -07:00
Andrew Kryczka 69679e7375 Fix range deletion tombstone ingestion with global seqno (#6429)
Summary:
Original author: jeffrey-xiao

If we are writing a global seqno for an ingested file, the range
tombstone metablock gets accessed and put into the cache during
ingestion preparation. At the time, the global seqno of the ingested
file has not yet been determined, so the cached block will not have a
global seqno. When the file is ingested and we read its range tombstone
metablock, it will be returned from the cache with no global seqno. In
that case, we use the actual seqnos stored in the range tombstones,
which are all zero, so the tombstones cover nothing.

This commit removes global_seqno_ variable from Block. When iterating
over a block, the global seqno for the block is determined by the
iterator instead of storing this mutable attribute in Block.
Additionally, this commit adds a regression test to check that keys are
deleted when ingesting a file with a global seqno and range deletion
tombstones.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6429

Differential Revision: D19961563

Pulled By: ajkr

fbshipit-source-id: 5cf777397fa3e452401f0bf0364b0750492487b7
2020-02-25 15:31:48 -08:00
sdong fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
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
2020-02-20 12:09:57 -08:00
sdong b931f84e56 Divide file_reader_writer.h and .cc (#5803)
Summary:
file_reader_writer.h and .cc contain several files and helper function, and it's hard to navigate. Separate it to multiple files and put them under file/
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5803

Test Plan: Build whole project using make and cmake.

Differential Revision: D17374550

fbshipit-source-id: 10efca907721e7a78ed25bbf74dc5410dea05987
2019-09-16 10:33:51 -07:00
Mike Kolupaev b4d7209428 Add an option to put first key of each sst block in the index (#5289)
Summary:
The first key is used to defer reading the data block until this file gets to the top of merging iterator's heap. For short range scans, most files never make it to the top of the heap, so this change can reduce read amplification by a lot sometimes.

Consider the following workload. There are a few data streams (we'll be calling them "logs"), each stream consisting of a sequence of blobs (we'll be calling them "records"). Each record is identified by log ID and a sequence number within the log. RocksDB key is concatenation of log ID and sequence number (big endian). Reads are mostly relatively short range scans, each within a single log. Writes are mostly sequential for each log, but writes to different logs are randomly interleaved. Compactions are disabled; instead, when we accumulate a few tens of sst files, we create a new column family and start writing to it.

So, a typical sst file consists of a few ranges of blocks, each range corresponding to one log ID (we use FlushBlockPolicy to cut blocks at log boundaries). A typical read would go like this. First, iterator Seek() reads one block from each sst file. Then a series of Next()s move through one sst file (since writes to each log are mostly sequential) until the subiterator reaches the end of this log in this sst file; then Next() switches to the next sst file and reads sequentially from that, and so on. Often a range scan will only return records from a small number of blocks in small number of sst files; in this case, the cost of initial Seek() reading one block from each file may be bigger than the cost of reading the actually useful blocks.

Neither iterate_upper_bound nor bloom filters can prevent reading one block from each file in Seek(). But this PR can: if the index contains first key from each block, we don't have to read the block until this block actually makes it to the top of merging iterator's heap, so for short range scans we won't read any blocks from most of the sst files.

This PR does the deferred block loading inside value() call. This is not ideal: there's no good way to report an IO error from inside value(). As discussed with siying offline, it would probably be better to change InternalIterator's interface to explicitly fetch deferred value and get status. I'll do it in a separate PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5289

Differential Revision: D15256423

Pulled By: al13n321

fbshipit-source-id: 750e4c39ce88e8d41662f701cf6275d9388ba46a
2019-06-24 20:54:04 -07:00
Vijay Nadimpalli 24b118ad98 Combine the read-ahead logic for user reads and compaction reads (#5431)
Summary:
Currently the read-ahead logic for user reads and compaction reads go through different code paths where compaction reads create new table readers and use `ReadaheadRandomAccessFile`. This change is to unify read-ahead logic to use read-ahead in BlockBasedTableReader::InitDataBlock(). As a result of the change  `ReadAheadRandomAccessFile` class and `new_table_reader_for_compaction_inputs` option will no longer be used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5431

Test Plan:
make check

Here is the benchmarking - https://gist.github.com/vjnadimpalli/083cf423f7b6aa12dcdb14c858bc18a5

Differential Revision: D15772533

Pulled By: vjnadimpalli

fbshipit-source-id: b71dca710590471ede6fb37553388654e2e479b9
2019-06-19 14:10:46 -07:00
Levi Tamasi 5355e527d9 Make the 'block read count' performance counters consistent (#5484)
Summary:
The patch brings the semantics of per-block-type read performance
context counters in sync with the generic block_read_count by only
incrementing the counter if the block was actually read from the file.
It also fixes index_block_read_count, which fell victim to the
refactoring in PR https://github.com/facebook/rocksdb/issues/5298.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5484

Test Plan: Extended the unit tests.

Differential Revision: D15887431

Pulled By: ltamasi

fbshipit-source-id: a3889759d0ac5759d56625d692cd828d1b9207a6
2019-06-18 19:03:24 -07:00
Siying Dong 8843129ece Move some memory related files from util/ to memory/ (#5382)
Summary:
Move arena, allocator, and memory tools under util to a separate memory/ directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382

Differential Revision: D15564655

Pulled By: siying

fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5
2019-05-30 17:44:09 -07:00
Vijay Nadimpalli 50e470791d Organizing rocksdb/table directory by format
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5373

Differential Revision: D15559425

Pulled By: vjnadimpalli

fbshipit-source-id: 5d6d6d615582bedd96a4b879bb25d429a6de8b55
2019-05-30 14:51:11 -07:00
Siying Dong e9e0101ca4 Move test related files under util/ to test_util/ (#5377)
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
2019-05-30 11:25:51 -07:00
Yuchi Chen 78a6e07c83 Fix compilation errors for 32bits/LITE/ios build. (#5220)
Summary:
When I build RocksDB for 32bits/LITE/iOS environment, some errors like the following.

`
table/block_based_table_reader.cc:971:44: error: implicit conversion loses integer precision: 'uint64_t'
      (aka 'unsigned long long') to 'size_t' (aka 'unsigned long') [-Werror,-Wshorten-64-to-32]
    size_t block_size = props_block_handle.size();
           ~~~~~~~~~~   ~~~~~~~~~~~~~~~~~~~^~~~~~

./util/file_reader_writer.h:177:8: error: private field 'env_' is not used [-Werror,-Wunused-private-field]
  Env* env_;
       ^
`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5220

Differential Revision: D15023481

Pulled By: siying

fbshipit-source-id: 1b5d121d3016f2b0a8a9a2cc1bd638479357f9f7
2019-04-22 16:02:16 -07:00
Sagar Vemuri efa948741c Use creation_time or mtime when file_creation_time=0 (#5184)
Summary:
We found an issue in Periodic Compactions (introduced in #5166) where files were not being picked up for compactions as all the SST files created with older versions of RocksDB have `file_creation_time` as 0. (Note that `file_creation_time` is a new table property introduced in #5166).

To address this, Periodic compactions now fall back to looking at the `creation_time` table property or the file's modification time (as given by the Env) when `file_creation_time` table property is found to be 0.

Here how the file's modification time (and, in turn, the file age) is computed now:
1. Use `file_creation_time` table property if it is > 0.
1. If not, then use `creation_time` table property if it is > 0.
1. If not, then use file's mtime stat metadata given by the underlying Env.
Don't consider the file at all for compaction if the modification time cannot be correctly determined based on the above conditions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5184

Differential Revision: D14907795

Pulled By: sagar0

fbshipit-source-id: 4bb2f3631f9a3e04470c674a1d13544584e1e56c
2019-04-18 22:39:34 -07:00
Sagar Vemuri d3d20dcdca Periodic Compactions (#5166)
Summary:
Introducing Periodic Compactions.

This feature allows all the files in a CF to be periodically compacted. It could help in catching any corruptions that could creep into the DB proactively as every file is constantly getting re-compacted.  And also, of course, it helps to cleanup data older than certain threshold.

- Introduced a new option `periodic_compaction_time` to control how long a file can live without being compacted in a CF.
- This works across all levels.
- The files are put in the same level after going through the compaction. (Related files in the same level are picked up as `ExpandInputstoCleanCut` is used).
- Compaction filters, if any, are invoked as usual.
- A new table property, `file_creation_time`, is introduced to implement this feature. This property is set to the time at which the SST file was created (and that time is given by the underlying Env/OS).

This feature can be enabled on its own, or in conjunction with `ttl`. It is possible to set a different time threshold for the bottom level when used in conjunction with ttl. Since `ttl` works only on 0 to last but one levels, you could set `ttl` to, say, 1 day, and `periodic_compaction_time` to, say, 7 days. Since `ttl < periodic_compaction_time` all files in last but one levels keep getting picked up based on ttl, and almost never based on periodic_compaction_time. The files in the bottom level get picked up for compaction based on `periodic_compaction_time`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5166

Differential Revision: D14884441

Pulled By: sagar0

fbshipit-source-id: 408426cbacb409c06386a98632dcf90bfa1bda47
2019-04-10 19:31:18 -07:00
Zhongyi Xie 26015f3b48 add compression options to table properties (#5081)
Summary:
Since we are planning to use dictionary compression and to use different compression level, it is quite useful to add compression options to TableProperties. For example, in MyRocks, if the feature is available, we can query from information_schema.rocksdb_sst_props to see if all sst files are converted to ZSTD dictionary compressions. Resolves https://github.com/facebook/rocksdb/issues/4992

With this PR, user can query table properties through `GetPropertiesOfAllTables` API and get compression options as std::string:
`window_bits=-14; level=32767; strategy=0; max_dict_bytes=0; zstd_max_train_bytes=0; enabled=0;`
or table_properties->ToString() will also contain it
`# data blocks=1; # entries=13; # deletions=0; # merge operands=0; # range deletions=0; raw key size=143; raw average key size=11.000000; raw value size=39; raw average value size=3.000000; data block size=120; index block size (user-key? 0, delta-value? 0)=27; filter block size=0; (estimated) table size=147; filter policy name=N/A; prefix extractor name=nullptr; column family ID=0; column family name=default; comparator name=leveldb.BytewiseComparator; merge operator name=nullptr; property collectors names=[]; SST file compression algo=Snappy; SST file compression options=window_bits=-14; level=32767; strategy=0; max_dict_bytes=0; zstd_max_train_bytes=0; enabled=0; ; creation time=1552946632; time stamp of earliest key=1552946632;`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5081

Differential Revision: D14716692

Pulled By: miasantreble

fbshipit-source-id: 7d2f2cf84e052bff876e71b4212cfdebf5be32dd
2019-04-02 14:52:34 -07:00
Shobhit Dayal b45b1cde3e Feature for sampling and reporting compressibility (#4842)
Summary:
This is a feature to sample data-block compressibility and and report them as stats. 1 in N (tunable) blocks is sampled for compressibility using two algorithms:
1. lz4 or snappy for fast compression
2. zstd or zlib for slow but higher compression.

The stats are reported to the caller as raw-bytes and compressed-bytes. The block continues to be compressed for storage using the specified CompressionType.

The db_bench_tool how has a command line option for specifying the sampling rate. It's default value is 0 (no sampling). To test the overhead for a certain value, users can compare the performance of db_bench_tool, varying the sampling rate. It is unlikely to have a noticeable impact for high values like 20.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4842

Differential Revision: D13629011

Pulled By: shobhitdayal

fbshipit-source-id: 14ca668bcab6499b2a1734edf848eb62a4f4fafa
2019-03-18 12:15:34 -07:00
Yanqin Jin 2d049ab7e8 Checksum properties block for block-based table (#4956)
Summary:
Always enable properties block checksum verification for block-based table. For external SST file ingested with 'write_global_seqno==true', we use 'DecodeEntrySlow' to parse its blocks' contents so that the process will not die upon failing the assertion possibly caused by corruption.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4956

Differential Revision: D14012741

Pulled By: riversand963

fbshipit-source-id: 8b766e6f54b36f8f9e074c0e19e0926ec3cce186
2019-02-11 11:50:01 -08:00
Andrew Kryczka 8ec3e72551 Cache dictionary used for decompressing data blocks (#4881)
Summary:
- If block cache disabled or not used for meta-blocks, `BlockBasedTableReader::Rep::uncompression_dict` owns the `UncompressionDict`. It is preloaded during `PrefetchIndexAndFilterBlocks`.
- If block cache is enabled and used for meta-blocks, block cache owns the `UncompressionDict`, which holds dictionary and digested dictionary when needed. It is never prefetched though there is a TODO for this in the code. The cache key is simply the compression dictionary block handle.
- New stats for compression dictionary accesses in block cache: "BLOCK_CACHE_COMPRESSION_DICT_*" and "compression_dict_block_read_count"
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4881

Differential Revision: D13663801

Pulled By: ajkr

fbshipit-source-id: bdcc54044e180855cdcc57639b493b0e016c9a3f
2019-01-23 18:15:47 -08:00
Yi Wu 512a5e3ef8 Fix BlockBasedTable not always using memory allocator if available (#4678)
Summary:
Fix block based table reader not using memory_allocator when allocating index blocks and compression dictionary blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4678

Differential Revision: D13054594

Pulled By: yiwu-arbug

fbshipit-source-id: 379f25bcc665395662511c4f873f4b7b55104ce2
2018-11-28 18:01:24 -08:00
Siying Dong b82e57d425 Remove two variables from BlockContents class and don't use class Block for compressed block (#4650)
Summary:
We carry compression type and "cachable" variables for every block in the block cache, while they take well-known values. 8-byte is wasted for each block (2-byte for useful information but it takes 8 bytes because of padding). With this change, these two variables are removed.

The cachable information is only useful in the process of reading the block. We use other information to infer from it. For compressed blocks, the compression type is a part of the block content itself so we can get it from there.

Some code is slightly refactored so that the cachable information can flow better.

Another change is to only use class BlockContents for compressed block, and narrow the class Block to only be used for uncompressed blocks, including blocks in compressed block cache. This can make the Block class less confusing. It also saves tens of bytes for each block in compressed block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4650

Differential Revision: D12969070

Pulled By: siying

fbshipit-source-id: 548b62724e9eb66993026429fd9c7c3acd1f95ed
2018-11-13 17:02:55 -08:00
Abhishek Madan eaaf1a6f05 Promote rocksdb.{deleted.keys,merge.operands} to main table properties (#4594)
Summary:
Since the number of range deletions are reported in
TableProperties, it is confusing to not report the number of merge
operands and point deletions as top-level properties; they are
accessible through the public API, but since they are not the "main"
properties, they do not appear in aggregated table properties, or the
string representation of table properties.

This change promotes those two property keys to
`rocksdb/table_properties.h`, adds corresponding uint64 members for
them, deprecates the old access methods `GetDeletedKeys()` and
`GetMergeOperands()` (though they are still usable for now), and removes
`InternalKeyPropertiesCollector`. The property key strings are the same
as before this change, so this should be able to read DBs written from older
versions (though I haven't tested this yet).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4594

Differential Revision: D12826893

Pulled By: abhimadan

fbshipit-source-id: 9e4e4fbdc5b0da161c89582566d184101ba8eb68
2018-10-30 15:34:27 -07:00
Maysam Yabandeh caf0f53a74 Index value delta encoding (#3983)
Summary:
Given that index value is a BlockHandle, which is basically an <offset, size> pair we can apply delta encoding on the values. The first value at each index restart interval encoded the full BlockHandle but the rest encode only the size. Refer to IndexBlockIter::DecodeCurrentValue for the detail of the encoding. This reduces the index size which helps using the  block cache more efficiently. The feature is enabled with using format_version 4.

The feature comes with a bit of cpu overhead which should be paid back by the higher cache hits due to smaller index block size.
Results with sysbench read-only using 4k blocks and using 16 index restart interval:
Format 2:
19585   rocksdb read-only range=100
Format 3:
19569   rocksdb read-only range=100
Format 4:
19352   rocksdb read-only range=100
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3983

Differential Revision: D8361343

Pulled By: maysamyabandeh

fbshipit-source-id: f882ee082322acac32b0072e2bdbb0b5f854e651
2018-08-09 16:58:40 -07:00
Siying Dong 8f06b4fa01 Separate some IndexBlockIter logic from BlockIter (#4136)
Summary:
Some logic only related to IndexBlockIter is separated from BlockIter to IndexBlockIter. This is done by writing an exclusive Seek() and SeekForPrev() for DataBlockIter, and all metadata block iter and tombstone block iter now use data block iter. Dealing with the BinarySeek() sharing problem by passing in the comparator to use.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4136

Reviewed By: maysamyabandeh

Differential Revision: D8859673

Pulled By: siying

fbshipit-source-id: 703e5e6824b82b7cbf4721f3594b94127797ca9e
2018-07-16 10:13:18 -07:00