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
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.
Most of changes were done through following comments:
unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`
by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147
Test Plan: See CI
Reviewed By: pdillinger
Differential Revision: D42796341
fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
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
Summary:
Greatly reduced the not-quite-copy-paste giant parameter lists
of rocksdb::NewTableBuilder, rocksdb::BuildTable,
BlockBasedTableBuilder::Rep ctor, and BlockBasedTableBuilder ctor.
Moved weird separate parameter `uint32_t column_family_id` of
TableFactory::NewTableBuilder into TableBuilderOptions.
Re-ordered parameters to TableBuilderOptions ctor, so that `uint64_t
target_file_size` is not randomly placed between uint64_t timestamps
(was easy to mix up).
Replaced a couple of fields of BlockBasedTableBuilder::Rep with a
FilterBuildingContext. The motivation for this change is making it
easier to pass along more data into new fields in FilterBuildingContext
(follow-up PR).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8240
Test Plan: ASAN make check
Reviewed By: mrambacher
Differential Revision: D28075891
Pulled By: pdillinger
fbshipit-source-id: fddb3dbb8260a0e8bdcbb51b877ebabf9a690d4f
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:
This PR merges the functionality of making the ColumnFamilyOptions, TableFactory, and DBOptions into Configurable into a single PR, resolving any merge conflicts
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5753
Reviewed By: ajkr
Differential Revision: D23385030
Pulled By: zhichao-cao
fbshipit-source-id: 8b977a7731556230b9b8c5a081b98e49ee4f160a
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
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
Summary:
The methods in convenience.h are used to compare/convert objects to/from strings. There is a mishmash of parameters in use here with more needed in the future. This PR replaces those parameters with a single structure.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6389
Reviewed By: siying
Differential Revision: D21163707
Pulled By: zhichao-cao
fbshipit-source-id: f807b4cc7e2b0af3871536b69546b2604dfa81bd
Summary:
This is a predecessor to the Configurable PR. This change moves the OptionTypeInfo maps closer to where they will be used.
When the Configurable changes are adopted, these values will become static and not associated with the OptionsHelper.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6198
Reviewed By: siying
Differential Revision: D20778108
Pulled By: zhichao-cao
fbshipit-source-id: a9f85fc73bc53503656e1958ecc1e764052fd1aa
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
Hui Xiao