rocksdb/db/import_column_family_job.h
mrambacher 3dff28cf9b Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033)
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>.  The shared ptr has some performance degradation on certain hardware classes.

For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere.  For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it.  The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.

There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold.  In those cases, the shared pointer was preserved.

Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:

6.17: readrandom   :      28.046 micros/op 854902 ops/sec;   61.3 MB/s (355999 of 355999 found)
6.18: readrandom   :      32.615 micros/op 735306 ops/sec;   52.7 MB/s (290999 of 290999 found)
PR: readrandom   :      27.500 micros/op 871909 ops/sec;   62.5 MB/s (367999 of 367999 found)

(Note that the times for 6.18 are prior to revert of the SystemClock).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033

Reviewed By: pdillinger

Differential Revision: D27014563

Pulled By: mrambacher

fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
2021-03-15 04:34:11 -07:00

77 lines
2.4 KiB
C++

#pragma once
#include <string>
#include <unordered_set>
#include <vector>
#include "db/column_family.h"
#include "db/dbformat.h"
#include "db/external_sst_file_ingestion_job.h"
#include "db/snapshot_impl.h"
#include "options/db_options.h"
#include "rocksdb/db.h"
#include "rocksdb/metadata.h"
#include "rocksdb/sst_file_writer.h"
#include "util/autovector.h"
namespace ROCKSDB_NAMESPACE {
struct EnvOptions;
class SystemClock;
// Imports a set of sst files as is into a new column family. Logic is similar
// to ExternalSstFileIngestionJob.
class ImportColumnFamilyJob {
public:
ImportColumnFamilyJob(VersionSet* versions, ColumnFamilyData* cfd,
const ImmutableDBOptions& db_options,
const EnvOptions& env_options,
const ImportColumnFamilyOptions& import_options,
const std::vector<LiveFileMetaData>& metadata,
const std::shared_ptr<IOTracer>& io_tracer)
: clock_(db_options.clock),
versions_(versions),
cfd_(cfd),
db_options_(db_options),
fs_(db_options_.fs, io_tracer),
env_options_(env_options),
import_options_(import_options),
metadata_(metadata),
io_tracer_(io_tracer) {}
// Prepare the job by copying external files into the DB.
Status Prepare(uint64_t next_file_number, SuperVersion* sv);
// Will execute the import job and prepare edit() to be applied.
// REQUIRES: Mutex held
Status Run();
// Cleanup after successful/failed job
void Cleanup(const Status& status);
VersionEdit* edit() { return &edit_; }
const autovector<IngestedFileInfo>& files_to_import() const {
return files_to_import_;
}
private:
// Open the external file and populate `file_to_import` with all the
// external information we need to import this file.
Status GetIngestedFileInfo(const std::string& external_file,
IngestedFileInfo* file_to_import,
SuperVersion* sv);
SystemClock* clock_;
VersionSet* versions_;
ColumnFamilyData* cfd_;
const ImmutableDBOptions& db_options_;
const FileSystemPtr fs_;
const EnvOptions& env_options_;
autovector<IngestedFileInfo> files_to_import_;
VersionEdit edit_;
const ImportColumnFamilyOptions& import_options_;
std::vector<LiveFileMetaData> metadata_;
const std::shared_ptr<IOTracer> io_tracer_;
};
} // namespace ROCKSDB_NAMESPACE