rocksdb/db/flush_job_test.cc
agiardullo 3bfd3d39a3 Use SST files for Transaction conflict detection
Summary:
Currently, transactions can fail even if there is no actual write conflict.  This is due to relying on only the memtables to check for write-conflicts.  Users have to tune memtable settings to try to avoid this, but it's hard to figure out exactly how to tune these settings.

With this diff, TransactionDB will use both memtables and SST files to determine if there are any write conflicts.  This relies on the fact that BlockBasedTable stores sequence numbers for all writes that happen after any open snapshot.  Also, D50295 is needed to prevent SingleDelete from disappearing writes (the TODOs in this test code will be fixed once the other diff is approved and merged).

Note that Optimistic transactions will still rely on tuning memtable settings as we do not want to read from SST while on the write thread.  Also, memtable settings can still be used to reduce how often TransactionDB needs to read SST files.

Test Plan: unit tests, db bench

Reviewers: rven, yhchiang, kradhakrishnan, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb, yoshinorim

Differential Revision: https://reviews.facebook.net/D50475
2015-12-11 12:34:11 -08:00

213 lines
7.6 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
#include <algorithm>
#include <map>
#include <string>
#include "db/flush_job.h"
#include "db/column_family.h"
#include "db/version_set.h"
#include "db/writebuffer.h"
#include "rocksdb/cache.h"
#include "util/file_reader_writer.h"
#include "util/string_util.h"
#include "util/testharness.h"
#include "util/testutil.h"
#include "table/mock_table.h"
namespace rocksdb {
// TODO(icanadi) Mock out everything else:
// 1. VersionSet
// 2. Memtable
class FlushJobTest : public testing::Test {
public:
FlushJobTest()
: env_(Env::Default()),
dbname_(test::TmpDir() + "/flush_job_test"),
table_cache_(NewLRUCache(50000, 16)),
write_buffer_(db_options_.db_write_buffer_size),
versions_(new VersionSet(dbname_, &db_options_, env_options_,
table_cache_.get(), &write_buffer_,
&write_controller_)),
shutting_down_(false),
mock_table_factory_(new mock::MockTableFactory()) {
EXPECT_OK(env_->CreateDirIfMissing(dbname_));
db_options_.db_paths.emplace_back(dbname_,
std::numeric_limits<uint64_t>::max());
// TODO(icanadi) Remove this once we mock out VersionSet
NewDB();
std::vector<ColumnFamilyDescriptor> column_families;
cf_options_.table_factory = mock_table_factory_;
column_families.emplace_back(kDefaultColumnFamilyName, cf_options_);
EXPECT_OK(versions_->Recover(column_families, false));
}
void NewDB() {
VersionEdit new_db;
new_db.SetLogNumber(0);
new_db.SetNextFile(2);
new_db.SetLastSequence(0);
const std::string manifest = DescriptorFileName(dbname_, 1);
unique_ptr<WritableFile> file;
Status s = env_->NewWritableFile(
manifest, &file, env_->OptimizeForManifestWrite(env_options_));
ASSERT_OK(s);
unique_ptr<WritableFileWriter> file_writer(
new WritableFileWriter(std::move(file), EnvOptions()));
{
log::Writer log(std::move(file_writer), 0, false);
std::string record;
new_db.EncodeTo(&record);
s = log.AddRecord(record);
}
ASSERT_OK(s);
// Make "CURRENT" file that points to the new manifest file.
s = SetCurrentFile(env_, dbname_, 1, nullptr);
}
Env* env_;
std::string dbname_;
EnvOptions env_options_;
std::shared_ptr<Cache> table_cache_;
WriteController write_controller_;
DBOptions db_options_;
WriteBuffer write_buffer_;
ColumnFamilyOptions cf_options_;
std::unique_ptr<VersionSet> versions_;
InstrumentedMutex mutex_;
std::atomic<bool> shutting_down_;
std::shared_ptr<mock::MockTableFactory> mock_table_factory_;
};
TEST_F(FlushJobTest, Empty) {
JobContext job_context(0);
auto cfd = versions_->GetColumnFamilySet()->GetDefault();
EventLogger event_logger(db_options_.info_log.get());
FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
db_options_, *cfd->GetLatestMutableCFOptions(),
env_options_, versions_.get(), &mutex_, &shutting_down_,
{}, kMaxSequenceNumber, &job_context, nullptr, nullptr,
nullptr, kNoCompression, nullptr, &event_logger);
ASSERT_OK(flush_job.Run());
job_context.Clean();
}
TEST_F(FlushJobTest, NonEmpty) {
JobContext job_context(0);
auto cfd = versions_->GetColumnFamilySet()->GetDefault();
auto new_mem = cfd->ConstructNewMemtable(*cfd->GetLatestMutableCFOptions(),
kMaxSequenceNumber);
new_mem->Ref();
auto inserted_keys = mock::MakeMockFile();
// Test data:
// seqno [ 1, 2 ... 8998, 8999, 9000, 9001, 9002 ... 9999 ]
// key [ 1001, 1002 ... 9998, 9999, 0, 1, 2 ... 999 ]
// Expected:
// smallest_key = "0"
// largest_key = "9999"
// smallest_seqno = 1
// smallest_seqno = 9999
for (int i = 1; i < 10000; ++i) {
std::string key(ToString((i + 1000) % 10000));
std::string value("value" + key);
new_mem->Add(SequenceNumber(i), kTypeValue, key, value);
InternalKey internal_key(key, SequenceNumber(i), kTypeValue);
inserted_keys.insert({internal_key.Encode().ToString(), value});
}
autovector<MemTable*> to_delete;
cfd->imm()->Add(new_mem, &to_delete);
for (auto& m : to_delete) {
delete m;
}
EventLogger event_logger(db_options_.info_log.get());
FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
db_options_, *cfd->GetLatestMutableCFOptions(),
env_options_, versions_.get(), &mutex_, &shutting_down_,
{}, kMaxSequenceNumber, &job_context, nullptr, nullptr,
nullptr, kNoCompression, nullptr, &event_logger);
FileMetaData fd;
mutex_.Lock();
ASSERT_OK(flush_job.Run(&fd));
mutex_.Unlock();
ASSERT_EQ(ToString(0), fd.smallest.user_key().ToString());
ASSERT_EQ(ToString(9999), fd.largest.user_key().ToString());
ASSERT_EQ(1, fd.smallest_seqno);
ASSERT_EQ(9999, fd.largest_seqno);
mock_table_factory_->AssertSingleFile(inserted_keys);
job_context.Clean();
}
TEST_F(FlushJobTest, Snapshots) {
JobContext job_context(0);
auto cfd = versions_->GetColumnFamilySet()->GetDefault();
auto new_mem = cfd->ConstructNewMemtable(*cfd->GetLatestMutableCFOptions(),
kMaxSequenceNumber);
std::vector<SequenceNumber> snapshots;
std::set<SequenceNumber> snapshots_set;
int keys = 10000;
int max_inserts_per_keys = 8;
Random rnd(301);
for (int i = 0; i < keys / 2; ++i) {
snapshots.push_back(rnd.Uniform(keys * (max_inserts_per_keys / 2)) + 1);
snapshots_set.insert(snapshots.back());
}
std::sort(snapshots.begin(), snapshots.end());
new_mem->Ref();
SequenceNumber current_seqno = 0;
auto inserted_keys = mock::MakeMockFile();
for (int i = 1; i < keys; ++i) {
std::string key(ToString(i));
int insertions = rnd.Uniform(max_inserts_per_keys);
for (int j = 0; j < insertions; ++j) {
std::string value(test::RandomHumanReadableString(&rnd, 10));
auto seqno = ++current_seqno;
new_mem->Add(SequenceNumber(seqno), kTypeValue, key, value);
// a key is visible only if:
// 1. it's the last one written (j == insertions - 1)
// 2. there's a snapshot pointing at it
bool visible = (j == insertions - 1) ||
(snapshots_set.find(seqno) != snapshots_set.end());
if (visible) {
InternalKey internal_key(key, seqno, kTypeValue);
inserted_keys.insert({internal_key.Encode().ToString(), value});
}
}
}
autovector<MemTable*> to_delete;
cfd->imm()->Add(new_mem, &to_delete);
for (auto& m : to_delete) {
delete m;
}
EventLogger event_logger(db_options_.info_log.get());
FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
db_options_, *cfd->GetLatestMutableCFOptions(),
env_options_, versions_.get(), &mutex_, &shutting_down_,
snapshots, kMaxSequenceNumber, &job_context, nullptr,
nullptr, nullptr, kNoCompression, nullptr, &event_logger);
mutex_.Lock();
ASSERT_OK(flush_job.Run());
mutex_.Unlock();
mock_table_factory_->AssertSingleFile(inserted_keys);
job_context.Clean();
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}