12b6cdeed3
Summary: A framework for tracing and replaying RocksDB operations. A binary trace file is created by capturing the DB operations, and it can be replayed back at the same rate using db_bench. - Column-families are supported - Multi-threaded tracing is supported. - TraceReader and TraceWriter are exposed to the user, so that tracing to various destinations can be enabled (say, to other messaging/logging services). By default, a FileTraceReader and FileTraceWriter are implemented to capture to a file and replay from it. - This is not yet ideal to be enabled in production due to large performance overhead, but it can be safely tried out in a shadow setup, say, for analyzing RocksDB operations. Currently supported DB operations: - Writes: -- Put -- Merge -- Delete -- SingleDelete -- DeleteRange -- Write - Reads: -- Get (point lookups) Pull Request resolved: https://github.com/facebook/rocksdb/pull/3837 Differential Revision: D7974837 Pulled By: sagar0 fbshipit-source-id: 8ec65aaf336504bc1f6ed0feae67f6ed5ef97a72
118 lines
3.4 KiB
C++
118 lines
3.4 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under both the GPLv2 (found in the
|
|
// COPYING file in the root directory) and Apache 2.0 License
|
|
// (found in the LICENSE.Apache file in the root directory).
|
|
|
|
#include "utilities/trace/file_trace_reader_writer.h"
|
|
|
|
#include "util/coding.h"
|
|
#include "util/file_reader_writer.h"
|
|
#include "util/trace_replay.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
const unsigned int FileTraceReader::kBufferSize = 1024; // 1KB
|
|
|
|
FileTraceReader::FileTraceReader(
|
|
std::unique_ptr<RandomAccessFileReader>&& reader)
|
|
: file_reader_(std::move(reader)),
|
|
offset_(0),
|
|
buffer_(new char[kBufferSize]) {}
|
|
|
|
FileTraceReader::~FileTraceReader() {
|
|
Close();
|
|
delete[] buffer_;
|
|
}
|
|
|
|
Status FileTraceReader::Close() {
|
|
file_reader_.reset();
|
|
return Status::OK();
|
|
}
|
|
|
|
Status FileTraceReader::Read(std::string* data) {
|
|
assert(file_reader_ != nullptr);
|
|
Status s = file_reader_->Read(offset_, kTraceMetadataSize, &result_, buffer_);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
if (result_.size() == 0) {
|
|
// No more data to read
|
|
// Todo: Come up with a better way to indicate end of data. May be this
|
|
// could be avoided once footer is introduced.
|
|
return Status::Incomplete();
|
|
}
|
|
if (result_.size() < kTraceMetadataSize) {
|
|
return Status::Corruption("Corrupted trace file.");
|
|
}
|
|
*data = result_.ToString();
|
|
offset_ += kTraceMetadataSize;
|
|
|
|
uint32_t payload_len =
|
|
DecodeFixed32(&buffer_[kTraceTimestampSize + kTraceTypeSize]);
|
|
|
|
// Read Payload
|
|
unsigned int bytes_to_read = payload_len;
|
|
unsigned int to_read =
|
|
bytes_to_read > kBufferSize ? kBufferSize : bytes_to_read;
|
|
while (to_read > 0) {
|
|
s = file_reader_->Read(offset_, to_read, &result_, buffer_);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
if (result_.size() < to_read) {
|
|
return Status::Corruption("Corrupted trace file.");
|
|
}
|
|
data->append(result_.data(), result_.size());
|
|
|
|
offset_ += to_read;
|
|
bytes_to_read -= to_read;
|
|
to_read = bytes_to_read > kBufferSize ? kBufferSize : bytes_to_read;
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
FileTraceWriter::~FileTraceWriter() { Close(); }
|
|
|
|
Status FileTraceWriter::Close() {
|
|
file_writer_.reset();
|
|
return Status::OK();
|
|
}
|
|
|
|
Status FileTraceWriter::Write(const Slice& data) {
|
|
return file_writer_->Append(data);
|
|
}
|
|
|
|
Status NewFileTraceReader(Env* env, const EnvOptions& env_options,
|
|
const std::string& trace_filename,
|
|
std::unique_ptr<TraceReader>* trace_reader) {
|
|
unique_ptr<RandomAccessFile> trace_file;
|
|
Status s = env->NewRandomAccessFile(trace_filename, &trace_file, env_options);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
|
|
unique_ptr<RandomAccessFileReader> file_reader;
|
|
file_reader.reset(
|
|
new RandomAccessFileReader(std::move(trace_file), trace_filename));
|
|
trace_reader->reset(new FileTraceReader(std::move(file_reader)));
|
|
return s;
|
|
}
|
|
|
|
Status NewFileTraceWriter(Env* env, const EnvOptions& env_options,
|
|
const std::string& trace_filename,
|
|
std::unique_ptr<TraceWriter>* trace_writer) {
|
|
unique_ptr<WritableFile> trace_file;
|
|
Status s = env->NewWritableFile(trace_filename, &trace_file, env_options);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
|
|
unique_ptr<WritableFileWriter> file_writer;
|
|
file_writer.reset(new WritableFileWriter(std::move(trace_file), env_options));
|
|
trace_writer->reset(new FileTraceWriter(std::move(file_writer)));
|
|
return s;
|
|
}
|
|
|
|
} // namespace rocksdb
|