rocksdb/db/flush_job_test.cc
Siying Dong d59549298f Skip deleted WALs during recovery
Summary:
This patch record min log number to keep to the manifest while flushing SST files to ignore them and any WAL older than them during recovery. This is to avoid scenarios when we have a gap between the WAL files are fed to the recovery procedure. The gap could happen by for example out-of-order WAL deletion. Such gap could cause problems in 2PC recovery where the prepared and commit entry are placed into two separate WAL and gap in the WALs could result into not processing the WAL with the commit entry and hence breaking the 2PC recovery logic.

Before the commit, for 2PC case, we determined which log number to keep in FindObsoleteFiles(). We looked at the earliest logs with outstanding prepare entries, or prepare entries whose respective commit or abort are in memtable. With the commit, the same calculation is done while we apply the SST flush. Just before installing the flush file, we precompute the earliest log file to keep after the flush finishes using the same logic (but skipping the memtables just flushed), record this information to the manifest entry for this new flushed SST file. This pre-computed value is also remembered in memory, and will later be used to determine whether a log file can be deleted. This value is unlikely to change until next flush because the commit entry will stay in memtable. (In WritePrepared, we could have removed the older log files as soon as all prepared entries are committed. It's not yet done anyway. Even if we do it, the only thing we loss with this new approach is earlier log deletion between two flushes, which does not guarantee to happen anyway because the obsolete file clean-up function is only executed after flush or compaction)

This min log number to keep is stored in the manifest using the safely-ignore customized field of AddFile entry, in order to guarantee that the DB generated using newer release can be opened by previous releases no older than 4.2.
Closes https://github.com/facebook/rocksdb/pull/3765

Differential Revision: D7747618

Pulled By: siying

fbshipit-source-id: d00c92105b4f83852e9754a1b70d6b64cb590729
2018-05-03 15:43:09 -07:00

238 lines
8.6 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 <algorithm>
#include <map>
#include <string>
#include "db/column_family.h"
#include "db/flush_job.h"
#include "db/version_set.h"
#include "rocksdb/cache.h"
#include "rocksdb/write_buffer_manager.h"
#include "table/mock_table.h"
#include "util/file_reader_writer.h"
#include "util/string_util.h"
#include "util/testharness.h"
#include "util/testutil.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"),
options_(),
db_options_(options_),
table_cache_(NewLRUCache(50000, 16)),
write_buffer_manager_(db_options_.db_write_buffer_size),
versions_(new VersionSet(dbname_, &db_options_, env_options_,
table_cache_.get(), &write_buffer_manager_,
&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());
db_options_.statistics = rocksdb::CreateDBStatistics();
// 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_;
Options options_;
ImmutableDBOptions db_options_;
std::shared_ptr<Cache> table_cache_;
WriteController write_controller_;
WriteBufferManager write_buffer_manager_;
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());
SnapshotChecker* snapshot_checker = nullptr; // not relavant
FlushJob flush_job(
dbname_, versions_->GetColumnFamilySet()->GetDefault(), db_options_,
*cfd->GetLatestMutableCFOptions(), env_options_, versions_.get(), &mutex_,
&shutting_down_, {}, kMaxSequenceNumber, snapshot_checker, &job_context,
nullptr, nullptr, nullptr, kNoCompression, nullptr, &event_logger, false);
{
InstrumentedMutexLock l(&mutex_);
flush_job.PickMemTable();
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 ]
// range-delete "9995" -> "9999" at seqno 10000
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);
if ((i + 1000) % 10000 < 9995) {
InternalKey internal_key(key, SequenceNumber(i), kTypeValue);
inserted_keys.insert({internal_key.Encode().ToString(), value});
}
}
new_mem->Add(SequenceNumber(10000), kTypeRangeDeletion, "9995", "9999a");
InternalKey internal_key("9995", SequenceNumber(10000), kTypeRangeDeletion);
inserted_keys.insert({internal_key.Encode().ToString(), "9999a"});
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());
SnapshotChecker* snapshot_checker = nullptr; // not relavant
FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
db_options_, *cfd->GetLatestMutableCFOptions(),
env_options_, versions_.get(), &mutex_, &shutting_down_,
{}, kMaxSequenceNumber, snapshot_checker, &job_context,
nullptr, nullptr, nullptr, kNoCompression,
db_options_.statistics.get(), &event_logger, true);
HistogramData hist;
FileMetaData fd;
mutex_.Lock();
flush_job.PickMemTable();
ASSERT_OK(flush_job.Run(nullptr, &fd));
mutex_.Unlock();
db_options_.statistics->histogramData(FLUSH_TIME, &hist);
ASSERT_GT(hist.average, 0.0);
ASSERT_EQ(ToString(0), fd.smallest.user_key().ToString());
ASSERT_EQ("9999a",
fd.largest.user_key().ToString()); // range tombstone end key
ASSERT_EQ(1, fd.smallest_seqno);
ASSERT_EQ(10000, fd.largest_seqno); // range tombstone seqnum 10000
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());
SnapshotChecker* snapshot_checker = nullptr; // not relavant
FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
db_options_, *cfd->GetLatestMutableCFOptions(),
env_options_, versions_.get(), &mutex_, &shutting_down_,
snapshots, kMaxSequenceNumber, snapshot_checker,
&job_context, nullptr, nullptr, nullptr, kNoCompression,
db_options_.statistics.get(), &event_logger, true);
mutex_.Lock();
flush_job.PickMemTable();
ASSERT_OK(flush_job.Run());
mutex_.Unlock();
mock_table_factory_->AssertSingleFile(inserted_keys);
HistogramData hist;
db_options_.statistics->histogramData(FLUSH_TIME, &hist);
ASSERT_GT(hist.average, 0.0);
job_context.Clean();
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}