dolysis/rocksdb
3
0
Fork 0
mirror of https://github.com/facebook/rocksdb.git synced 2024-11-26 07:30:54 +00:00
Code Issues Packages Projects Releases Wiki Activity

WritePrepared Txn: Recovery

Browse source 
Summary:
Recover txns from the WAL. Also added some unit tests.
Closes https://github.com/facebook/rocksdb/pull/2901

Differential Revision: D5859596

Pulled By: maysamyabandeh

fbshipit-source-id: 6424967b231388093b4effffe0a3b1b7ec8caeb0
This commit is contained in:
Maysam Yabandeh 2017-09-28 16:43:04 -07:00 committed by Facebook Github Bot
parent 8c724f5c7f
commit 385049baf2
19 changed files with 802 additions and 202 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
db/db_impl.cc
View file

@ -940,6 +940,10 @@ Status DBImpl::GetImpl(const ReadOptions& read_options,
SequenceNumber snapshot;
if (read_options.snapshot != nullptr) {
// Note: In WritePrepared txns this is not necessary but not harmful either.
// Because prep_seq > snapshot => commit_seq > snapshot so if a snapshot is
// specified we should be fine with skipping seq numbers that are greater
// than that.
snapshot = reinterpret_cast<const SnapshotImpl*>(
read_options.snapshot)->number_;
} else {

12
db/db_impl.h
View file

@ -510,9 +510,11 @@ class DBImpl : public DB {
uint64_t log_number_;
std::string name_;
WriteBatch* batch_;
// The seq number of the first key in the batch
SequenceNumber seq_;
explicit RecoveredTransaction(const uint64_t log, const std::string& name,
WriteBatch* batch)
: log_number_(log), name_(name), batch_(batch) {}
WriteBatch* batch, SequenceNumber seq)
: log_number_(log), name_(name), batch_(batch), seq_(seq) {}
~RecoveredTransaction() { delete batch_; }
};
@ -534,8 +536,9 @@ class DBImpl : public DB {
}
void InsertRecoveredTransaction(const uint64_t log, const std::string& name,
WriteBatch* batch) {
recovered_transactions_[name] = new RecoveredTransaction(log, name, batch);
WriteBatch* batch, SequenceNumber seq) {
recovered_transactions_[name] =
new RecoveredTransaction(log, name, batch, seq);
MarkLogAsContainingPrepSection(log);
}
@ -640,6 +643,7 @@ class DBImpl : public DB {
friend class PessimisticTransaction;
friend class WriteCommittedTxn;
friend class WritePreparedTxn;
friend class WritePreparedTxnDB;
friend class WriteBatchWithIndex;
#ifndef ROCKSDB_LITE
friend class ForwardIterator;

2
db/db_impl_files.cc
View file

@ -48,6 +48,7 @@ uint64_t DBImpl::FindMinPrepLogReferencedByMemTable() {
return min_log;
}
// TODO(myabandeh): Avoid using locks
void DBImpl::MarkLogAsHavingPrepSectionFlushed(uint64_t log) {
assert(log != 0);
std::lock_guard<std::mutex> lock(prep_heap_mutex_);
@ -56,6 +57,7 @@ void DBImpl::MarkLogAsHavingPrepSectionFlushed(uint64_t log) {
it->second += 1;
}
// TODO(myabandeh): Avoid using locks
void DBImpl::MarkLogAsContainingPrepSection(uint64_t log) {
assert(log != 0);
std::lock_guard<std::mutex> lock(prep_heap_mutex_);

4
db/db_impl_write.cc
View file

@ -264,9 +264,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
} else {
SequenceNumber next_sequence = current_sequence;
for (auto* writer : write_group) {
if (writer->ShouldWriteToMemtable()) {
writer->sequence = next_sequence;
}
writer->sequence = next_sequence;
if (seq_per_batch_) {
next_sequence++;
} else if (writer->ShouldWriteToMemtable()) {

2
db/memtable.cc
View file

@ -475,7 +475,7 @@ void MemTable::Add(SequenceNumber s, ValueType type,
}
// The first sequence number inserted into the memtable
assert(first_seqno_ == 0 || s > first_seqno_);
assert(first_seqno_ == 0 || s >= first_seqno_);
if (first_seqno_ == 0) {
first_seqno_.store(s, std::memory_order_relaxed);

18
db/version_set.cc
View file

@ -2655,7 +2655,14 @@ Status VersionSet::LogAndApply(ColumnFamilyData* column_family_data,
void VersionSet::LogAndApplyCFHelper(VersionEdit* edit) {
assert(edit->IsColumnFamilyManipulation());
edit->SetNextFile(next_file_number_.load());
edit->SetLastSequence(last_sequence_);
// The log might have data that is not visible to memtbale and hence have not
// updated the last_sequence_ yet. It is also possible that the log has is
// expecting some new data that is not written yet. Since LastSequence is an
// upper bound on the sequence, it is ok to record
// last_to_be_written_sequence_ as the last sequence.
edit->SetLastSequence(db_options_->concurrent_prepare
? last_to_be_written_sequence_
: last_sequence_);
if (edit->is_column_family_drop_) {
// if we drop column family, we have to make sure to save max column family,
// so that we don't reuse existing ID
@ -2678,7 +2685,14 @@ void VersionSet::LogAndApplyHelper(ColumnFamilyData* cfd,
edit->SetPrevLogNumber(prev_log_number_);
}
edit->SetNextFile(next_file_number_.load());
edit->SetLastSequence(last_sequence_);
// The log might have data that is not visible to memtbale and hence have not
// updated the last_sequence_ yet. It is also possible that the log has is
// expecting some new data that is not written yet. Since LastSequence is an
// upper bound on the sequence, it is ok to record
// last_to_be_written_sequence_ as the last sequence.
edit->SetLastSequence(db_options_->concurrent_prepare
? last_to_be_written_sequence_
: last_sequence_);
builder->Apply(edit);
}

86
db/write_batch.cc
View file

@ -366,7 +366,11 @@ Status WriteBatch::Iterate(Handler* handler) const {
input.remove_prefix(WriteBatchInternal::kHeader);
Slice key, value, blob, xid;
bool first_tag = true;
// Sometimes a sub-batch starts with a Noop. We want to exclude such Noops as
// the batch boundry sybmols otherwise we would mis-count the number of
// batches. We do that by checking whether the accumulated batch is empty
// before seeing the next Noop.
bool empty_batch = true;
int found = 0;
Status s;
while (s.ok() && !input.empty() && handler->Continue()) {
@ -385,6 +389,7 @@ Status WriteBatch::Iterate(Handler* handler) const {
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_PUT));
s = handler->PutCF(column_family, key, value);
empty_batch = false;
found++;
break;
case kTypeColumnFamilyDeletion:
@ -392,6 +397,7 @@ Status WriteBatch::Iterate(Handler* handler) const {
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_DELETE));
s = handler->DeleteCF(column_family, key);
empty_batch = false;
found++;
break;
case kTypeColumnFamilySingleDeletion:
@ -399,6 +405,7 @@ Status WriteBatch::Iterate(Handler* handler) const {
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_SINGLE_DELETE));
s = handler->SingleDeleteCF(column_family, key);
empty_batch = false;
found++;
break;
case kTypeColumnFamilyRangeDeletion:
@ -406,6 +413,7 @@ Status WriteBatch::Iterate(Handler* handler) const {
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_DELETE_RANGE));
s = handler->DeleteRangeCF(column_family, key, value);
empty_batch = false;
found++;
break;
case kTypeColumnFamilyMerge:
@ -413,38 +421,44 @@ Status WriteBatch::Iterate(Handler* handler) const {
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_MERGE));
s = handler->MergeCF(column_family, key, value);
empty_batch = false;
found++;
break;
case kTypeLogData:
handler->LogData(blob);
empty_batch = true;
break;
case kTypeBeginPrepareXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_BEGIN_PREPARE));
handler->MarkBeginPrepare();
empty_batch = false;
break;
case kTypeEndPrepareXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_END_PREPARE));
handler->MarkEndPrepare(xid);
empty_batch = true;
break;
case kTypeCommitXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_COMMIT));
handler->MarkCommit(xid);
empty_batch = true;
break;
case kTypeRollbackXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_ROLLBACK));
handler->MarkRollback(xid);
empty_batch = true;
break;
case kTypeNoop:
handler->MarkNoop(first_tag);
handler->MarkNoop(empty_batch);
empty_batch = true;
break;
default:
return Status::Corruption("unknown WriteBatch tag");
}
first_tag = false;
}
if (!s.ok()) {
return s;
@ -841,9 +855,12 @@ class MemTableInserter : public WriteBatch::Handler {
PostMapType mem_post_info_map_;
// current recovered transaction we are rebuilding (recovery)
WriteBatch* rebuilding_trx_;
SequenceNumber rebuilding_trx_seq_;
// Increase seq number once per each write batch. Otherwise increase it once
// per key.
bool seq_per_batch_;
// Whether the memtable write will be done only after the commit
bool write_after_commit_;
MemPostInfoMap& GetPostMap() {
assert(concurrent_memtable_writes_);
@ -873,7 +890,11 @@ class MemTableInserter : public WriteBatch::Handler {
post_info_created_(false),
has_valid_writes_(has_valid_writes),
rebuilding_trx_(nullptr),
seq_per_batch_(seq_per_batch) {
seq_per_batch_(seq_per_batch),
// Write after commit currently uses one seq per key (instead of per
// batch). So seq_per_batch being false indicates write_after_commit
// approach.
write_after_commit_(!seq_per_batch) {
assert(cf_mems_);
}
@ -952,7 +973,10 @@ class MemTableInserter : public WriteBatch::Handler {
const Slice& value) override {
if (rebuilding_trx_ != nullptr) {
WriteBatchInternal::Put(rebuilding_trx_, column_family_id, key, value);
return Status::OK();
if (write_after_commit_) {
return Status::OK();
}
// else insert the values to the memtable right away
}
Status seek_status;
@ -1030,7 +1054,10 @@ class MemTableInserter : public WriteBatch::Handler {
const Slice& key) override {
if (rebuilding_trx_ != nullptr) {
WriteBatchInternal::Delete(rebuilding_trx_, column_family_id, key);
return Status::OK();
if (write_after_commit_) {
return Status::OK();
}
// else insert the values to the memtable right away
}
Status seek_status;
@ -1046,7 +1073,10 @@ class MemTableInserter : public WriteBatch::Handler {
const Slice& key) override {
if (rebuilding_trx_ != nullptr) {
WriteBatchInternal::SingleDelete(rebuilding_trx_, column_family_id, key);
return Status::OK();
if (write_after_commit_) {
return Status::OK();
}
// else insert the values to the memtable right away
}
Status seek_status;
@ -1064,7 +1094,10 @@ class MemTableInserter : public WriteBatch::Handler {
if (rebuilding_trx_ != nullptr) {
WriteBatchInternal::DeleteRange(rebuilding_trx_, column_family_id,
begin_key, end_key);
return Status::OK();
if (write_after_commit_) {
return Status::OK();
}
// else insert the values to the memtable right away
}
Status seek_status;
@ -1094,7 +1127,10 @@ class MemTableInserter : public WriteBatch::Handler {
assert(!concurrent_memtable_writes_);
if (rebuilding_trx_ != nullptr) {
WriteBatchInternal::Merge(rebuilding_trx_, column_family_id, key, value);
return Status::OK();
if (write_after_commit_) {
return Status::OK();
}
// else insert the values to the memtable right away
}
Status seek_status;
@ -1200,6 +1236,7 @@ class MemTableInserter : public WriteBatch::Handler {
// we are now iterating through a prepared section
rebuilding_trx_ = new WriteBatch();
rebuilding_trx_seq_ = sequence_;
if (has_valid_writes_ != nullptr) {
*has_valid_writes_ = true;
}
@ -1215,7 +1252,7 @@ class MemTableInserter : public WriteBatch::Handler {
if (recovering_log_number_ != 0) {
assert(db_->allow_2pc());
db_->InsertRecoveredTransaction(recovering_log_number_, name.ToString(),
rebuilding_trx_);
rebuilding_trx_, rebuilding_trx_seq_);
rebuilding_trx_ = nullptr;
} else {
assert(rebuilding_trx_ == nullptr);
@ -1226,10 +1263,10 @@ class MemTableInserter : public WriteBatch::Handler {
return Status::OK();
}
Status MarkNoop(bool first_tag) override {
Status MarkNoop(bool empty_batch) override {
// A hack in pessimistic transaction could result into a noop at the start
// of the write batch, that should be ignored.
if (!first_tag) {
if (!empty_batch) {
// In the absence of Prepare markers, a kTypeNoop tag indicates the end of
// a batch. This happens when write batch commits skipping the prepare
// phase.
@ -1257,12 +1294,13 @@ class MemTableInserter : public WriteBatch::Handler {
// at this point individual CF lognumbers will prevent
// duplicate re-insertion of values.
assert(log_number_ref_ == 0);
// all insertes must reference this trx log number
log_number_ref_ = trx->log_number_;
s = trx->batch_->Iterate(this);
// TODO(myabandeh): In WritePrepared txn, a commit marker should
// reference the log that contains the prepare marker.
log_number_ref_ = 0;
if (write_after_commit_) {
// all insertes must reference this trx log number
log_number_ref_ = trx->log_number_;
s = trx->batch_->Iterate(this);
log_number_ref_ = 0;
}
// else the values are already inserted before the commit
if (s.ok()) {
db_->DeleteRecoveredTransaction(name.ToString());
@ -1272,12 +1310,10 @@ class MemTableInserter : public WriteBatch::Handler {
}
}
} else {
// TODO(myabandeh): In WritePrepared txn, a commit marker should
// reference the log that contains the prepare marker. This is to be able
// to reconsutrct the prepared list after recovery.
// TODO(myabandeh): In WritePrepared txn, we do not reach here since
// disable_memtable is set for commit.
assert(log_number_ref_ > 0);
// When writes are not delayed until commit, there is no disconnect
// between a memtable write and the WAL that supports it. So the commit
// need not reference any log as the only log to which it depends.
assert(!write_after_commit_ || log_number_ref_ > 0);
}
const bool batch_boundry = true;
MaybeAdvanceSeq(batch_boundry);
@ -1330,6 +1366,8 @@ Status WriteBatchInternal::InsertInto(
nullptr /*has_valid_writes*/, seq_per_batch);
for (auto w : write_group) {
if (!w->ShouldWriteToMemtable()) {
inserter.MaybeAdvanceSeq(true);
w->sequence = inserter.sequence();
continue;
}
SetSequence(w->batch, inserter.sequence());

5
db/write_batch_test.cc
View file

@ -18,7 +18,6 @@
#include "rocksdb/utilities/write_batch_with_index.h"
#include "rocksdb/write_buffer_manager.h"
#include "table/scoped_arena_iterator.h"
#include "util/logging.h"
#include "util/string_util.h"
#include "util/testharness.h"
@ -299,8 +298,8 @@ namespace {
seen += "MarkEndPrepare(" + xid.ToString() + ")";
return Status::OK();
}
virtual Status MarkNoop(bool first_tag) override {
seen += "MarkNoop(" + std::string(first_tag ? "true" : "false") + ")";
virtual Status MarkNoop(bool empty_batch) override {
seen += "MarkNoop(" + std::string(empty_batch ? "true" : "false") + ")";
return Status::OK();
}
virtual Status MarkCommit(const Slice& xid) override {

1
db/write_thread.cc
View file

@ -394,6 +394,7 @@ size_t WriteThread::EnterAsBatchGroupLeader(Writer* leader,
write_group->last_writer = w;
write_group->size++;
}
TEST_SYNC_POINT_CALLBACK("WriteThread::EnterAsBatchGroupLeader:End", w);
return size;
}

3
db/write_thread.h
View file

@ -14,6 +14,7 @@
#include <type_traits>
#include <vector>
#include "db/dbformat.h"
#include "db/write_callback.h"
#include "monitoring/instrumented_mutex.h"
#include "rocksdb/options.h"
@ -142,6 +143,7 @@ class WriteThread {
made_waitable(false),
state(STATE_INIT),
write_group(nullptr),
sequence(kMaxSequenceNumber),
link_older(nullptr),
link_newer(nullptr) {}
@ -158,6 +160,7 @@ class WriteThread {
made_waitable(false),
state(STATE_INIT),
write_group(nullptr),
sequence(kMaxSequenceNumber),
link_older(nullptr),
link_newer(nullptr) {}

15
include/rocksdb/utilities/transaction.h
View file

@ -460,6 +460,14 @@ class Transaction {
TransactionState GetState() const { return txn_state_; }
void SetState(TransactionState state) { txn_state_ = state; }
// NOTE: Experimental feature
// The globally unique id with which the transaction is identified. This id
// might or might not be set depending on the implementation. Similarly the
// implementation decides the point in lifetime of a transaction at which it
// assigns the id. Although currently it is the case, the id is not guaranteed
// to remain the same across restarts.
uint64_t GetId() { return id_; }
protected:
explicit Transaction(const TransactionDB* db) {}
Transaction() {}
@ -472,7 +480,14 @@ class Transaction {
// Execution status of the transaction.
std::atomic<TransactionState> txn_state_;
uint64_t id_ = 0;
virtual void SetId(uint64_t id) {
assert(id_ == 0);
id_ = id;
}
private:
friend class PessimisticTransactionDB;
// No copying allowed
Transaction(const Transaction&);
void operator=(const Transaction&);

2
include/rocksdb/write_batch.h
View file

@ -244,7 +244,7 @@ class WriteBatch : public WriteBatchBase {
return Status::InvalidArgument("MarkEndPrepare() handler not defined.");
}
virtual Status MarkNoop(bool first_tag) {
virtual Status MarkNoop(bool empty_batch) {
return Status::InvalidArgument("MarkNoop() handler not defined.");
}

43
utilities/transactions/pessimistic_transaction_db.cc
View file

@ -115,6 +115,8 @@ Status PessimisticTransactionDB::Initialize(
Transaction* real_trx = BeginTransaction(w_options, t_options, nullptr);
assert(real_trx);
real_trx->SetLogNumber(recovered_trx->log_number_);
assert(recovered_trx->seq_ != kMaxSequenceNumber);
real_trx->SetId(recovered_trx->seq_);
s = real_trx->SetName(recovered_trx->name_);
if (!s.ok()) {
@ -133,6 +135,23 @@ Status PessimisticTransactionDB::Initialize(
return s;
}
Status WritePreparedTxnDB::Initialize(
const std::vector<size_t>& compaction_enabled_cf_indices,
const std::vector<ColumnFamilyHandle*>& handles) {
auto dbimpl = reinterpret_cast<DBImpl*>(GetRootDB());
assert(dbimpl != nullptr);
auto rtxns = dbimpl->recovered_transactions();
for (auto rtxn : rtxns) {
AddPrepared(rtxn.second->seq_);
}
SequenceNumber prev_max = max_evicted_seq_;
SequenceNumber last_seq = db_impl_->GetLatestSequenceNumber();
AdvanceMaxEvictedSeq(prev_max, last_seq);
auto s = PessimisticTransactionDB::Initialize(compaction_enabled_cf_indices,
handles);
return s;
}
Transaction* WriteCommittedTxnDB::BeginTransaction(
const WriteOptions& write_options, const TransactionOptions& txn_options,
Transaction* old_txn) {
@ -547,6 +566,19 @@ void PessimisticTransactionDB::UnregisterTransaction(Transaction* txn) {
transactions_.erase(it);
}
Status WritePreparedTxnDB::Get(const ReadOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key, PinnableSlice* value) {
// We are fine with the latest committed value. This could be done by
// specifying the snapshot as kMaxSequenceNumber.
WritePreparedTxnReadCallback callback(this, kMaxSequenceNumber);
bool* dont_care = nullptr;
// Note: no need to specify a snapshot for read options as no specific
// snapshot is requested by the user.
return db_impl_->GetImpl(options, column_family, key, value, dont_care,
&callback);
}
// Returns true if commit_seq <= snapshot_seq
bool WritePreparedTxnDB::IsInSnapshot(uint64_t prep_seq,
uint64_t snapshot_seq) {
@ -571,14 +603,14 @@ bool WritePreparedTxnDB::IsInSnapshot(uint64_t prep_seq,
CommitEntry64b dont_care;
CommitEntry cached;
bool exist = GetCommitEntry(indexed_seq, &dont_care, &cached);
if (!exist) {
// It is not committed, so it must be still prepared
return false;
}
if (prep_seq == cached.prep_seq) {
if (exist && prep_seq == cached.prep_seq) {
// It is committed and also not evicted from commit cache
return cached.commit_seq <= snapshot_seq;
}
// else it could be committed but not inserted in the map which could happen
// after recovery, or it could be committed and evicted by another commit, or
// never committed.
// At this point we dont know if it was committed or it is still prepared
auto max_evicted_seq = max_evicted_seq_.load(std::memory_order_acquire);
if (max_evicted_seq < prep_seq) {
@ -618,6 +650,7 @@ bool WritePreparedTxnDB::IsInSnapshot(uint64_t prep_seq,
void WritePreparedTxnDB::AddPrepared(uint64_t seq) {
ROCKS_LOG_DEBUG(info_log_, "Txn %" PRIu64 " Prepareing", seq);
assert(seq > max_evicted_seq_);
WriteLock wl(&prepared_mutex_);
prepared_txns_.push(seq);
}

16
utilities/transactions/pessimistic_transaction_db.h
View file

@ -33,8 +33,9 @@ class PessimisticTransactionDB : public TransactionDB {
virtual ~PessimisticTransactionDB();
Status Initialize(const std::vector<size_t>& compaction_enabled_cf_indices,
const std::vector<ColumnFamilyHandle*>& handles);
virtual Status Initialize(
const std::vector<size_t>& compaction_enabled_cf_indices,
const std::vector<ColumnFamilyHandle*>& handles);
Transaction* BeginTransaction(const WriteOptions& write_options,
const TransactionOptions& txn_options,
@ -191,10 +192,19 @@ class WritePreparedTxnDB : public PessimisticTransactionDB {
virtual ~WritePreparedTxnDB() {}
virtual Status Initialize(
const std::vector<size_t>& compaction_enabled_cf_indices,
const std::vector<ColumnFamilyHandle*>& handles) override;
Transaction* BeginTransaction(const WriteOptions& write_options,
const TransactionOptions& txn_options,
Transaction* old_txn) override;
using DB::Get;
virtual Status Get(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) override;
// Check whether the transaction that wrote the value with seqeunce number seq
// is visible to the snapshot with sequence number snapshot_seq
bool IsInSnapshot(uint64_t seq, uint64_t snapshot_seq);
@ -294,6 +304,8 @@ class WritePreparedTxnDB : public PessimisticTransactionDB {
friend class PreparedHeap_BasicsTest_Test;
friend class WritePreparedTxnDBMock;
friend class WritePreparedTransactionTest_AdvanceMaxEvictedSeqBasicTest_Test;
friend class WritePreparedTransactionTest_BasicRecoveryTest_Test;
friend class WritePreparedTransactionTest_IsInSnapshotEmptyMapTest_Test;
void init(const TransactionDBOptions& /* unused */) {
// Adcance max_evicted_seq_ no more than 100 times before the cache wraps

164
utilities/transactions/transaction_test.cc
View file

@ -4640,89 +4640,107 @@ TEST_P(TransactionTest, MemoryLimitTest) {
delete txn;
}
// This test clarfies the existing expectation from the sequence number
// This test clarifies the existing expectation from the sequence number
// algorithm. It could detect mistakes in updating the code but it is not
// necessarily the one acceptable way. If the algorithm is legitimately changed,
// this unit test should be updated as well.
TEST_P(TransactionTest, SeqAdvanceTest) {
auto pdb = reinterpret_cast<PessimisticTransactionDB*>(db);
DBImpl* db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
auto seq = db_impl->GetLatestSequenceNumber();
auto exp_seq = seq;
// Test DB's internal txn. It involves no prepare phase nor a commit marker.
WriteOptions wopts;
auto s = db->Put(wopts, "key", "value");
// Consume one seq per key
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
FlushOptions fopt;
// Doing it twice might detect some bugs
s = db->Put(wopts, "key", "value");
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Do the test with NUM_BRANCHES branches in it. Each run of a test takes some
// of the branches. This is the same as counting a binary number where i-th
// bit represents whether we take branch i in the represented by the number.
const size_t NUM_BRANCHES = 8;
// Helper function that shows if the branch is to be taken in the run
// represented by the number n.
auto branch_do = [&](size_t n, size_t* branch) {
assert(*branch < NUM_BRANCHES);
const size_t filter = static_cast<size_t>(1) << *branch;
return n & filter;
};
const size_t max_n = static_cast<size_t>(1) << NUM_BRANCHES;
for (size_t n = 0; n < max_n; n++, ReOpen()) {
DBImpl* db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
size_t branch = 0;
auto seq = db_impl->GetLatestSequenceNumber();
exp_seq = seq;
txn_t0(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Testing directly writing a write batch. Functionality-wise it is equivalent
// to commit without prepare.
WriteBatch wb;
wb.Put("k1", "v1");
wb.Put("k2", "v2");
wb.Put("k3", "v3");
s = db->Write(wopts, &wb);
// One seq per key.
exp_seq += 3;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
// A full 2pc txn that also involves a commit marker.
TransactionOptions txn_options;
WriteOptions write_options;
Transaction* txn = db->BeginTransaction(write_options, txn_options);
s = txn->SetName("xid");
ASSERT_OK(s);
s = txn->Put(Slice("foo"), Slice("bar"));
s = txn->Put(Slice("foo2"), Slice("bar2"));
s = txn->Put(Slice("foo3"), Slice("bar3"));
s = txn->Put(Slice("foo4"), Slice("bar4"));
s = txn->Put(Slice("foo5"), Slice("bar5"));
ASSERT_OK(s);
s = txn->Prepare();
ASSERT_OK(s);
// Consume one seq per key
exp_seq += 5;
s = txn->Commit();
ASSERT_OK(s);
// Doing it twice might detect some bugs
txn_t0(1);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
s = db->Put(wopts, "key", "value");
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
delete txn;
txn_t1(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Commit without prepare. It shoudl write to DB without a commit marker.
txn = db->BeginTransaction(write_options, txn_options);
s = txn->SetName("xid2");
ASSERT_OK(s);
s = txn->Put(Slice("foo"), Slice("bar"));
s = txn->Put(Slice("foo2"), Slice("bar2"));
s = txn->Put(Slice("foo3"), Slice("bar3"));
s = txn->Put(Slice("foo4"), Slice("bar4"));
s = txn->Put(Slice("foo5"), Slice("bar5"));
ASSERT_OK(s);
s = txn->Commit();
ASSERT_OK(s);
// One seq per key
exp_seq += 5;
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
pdb->UnregisterTransaction(txn);
delete txn;
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
txn_t3(0);
// Since commit marker does not write to memtable, the last seq number is
// not updated immediately. But the advance should be visible after the next
// write.
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
txn_t0(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
txn_t2(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
}
}
} // namespace rocksdb

99
utilities/transactions/transaction_test.h
View file

@ -124,6 +124,105 @@ class TransactionTest : public ::testing::TestWithParam<
}
return s;
}
std::atomic<size_t> linked = {0};
std::atomic<size_t> exp_seq = {0};
std::atomic<size_t> commit_writes = {0};
std::atomic<size_t> expected_commits = {0};
std::function<void(size_t, Status)> txn_t0_with_status = [&](size_t index,
Status exp_s) {
// Test DB's internal txn. It involves no prepare phase nor a commit marker.
WriteOptions wopts;
auto s = db->Put(wopts, "key" + std::to_string(index), "value");
ASSERT_EQ(exp_s, s);
if (txn_db_options.write_policy == TxnDBWritePolicy::WRITE_COMMITTED) {
// Consume one seq per key
exp_seq++;
} else {
// Consume one seq per batch
exp_seq++;
}
};
std::function<void(size_t)> txn_t0 = [&](size_t index) {
return txn_t0_with_status(index, Status::OK());
};
std::function<void(size_t)> txn_t1 = [&](size_t index) {
// Testing directly writing a write batch. Functionality-wise it is
// equivalent to commit without prepare.
WriteBatch wb;
auto istr = std::to_string(index);
wb.Put("k1" + istr, "v1");
wb.Put("k2" + istr, "v2");
wb.Put("k3" + istr, "v3");
WriteOptions wopts;
auto s = db->Write(wopts, &wb);
if (txn_db_options.write_policy == TxnDBWritePolicy::WRITE_COMMITTED) {
// Consume one seq per key
exp_seq += 3;
;
} else {
// Consume one seq per batch
exp_seq++;
}
ASSERT_OK(s);
};
std::function<void(size_t)> txn_t2 = [&](size_t index) {
// Commit without prepare. It should write to DB without a commit marker.
TransactionOptions txn_options;
WriteOptions write_options;
Transaction* txn = db->BeginTransaction(write_options, txn_options);
auto istr = std::to_string(index);
auto s = txn->SetName("xid" + istr);
ASSERT_OK(s);
s = txn->Put(Slice("foo" + istr), Slice("bar"));
s = txn->Put(Slice("foo2" + istr), Slice("bar2"));
s = txn->Put(Slice("foo3" + istr), Slice("bar3"));
s = txn->Put(Slice("foo4" + istr), Slice("bar4"));
ASSERT_OK(s);
s = txn->Commit();
ASSERT_OK(s);
if (txn_db_options.write_policy == TxnDBWritePolicy::WRITE_COMMITTED) {
// Consume one seq per key
exp_seq += 4;
} else {
// Consume one seq per batch
exp_seq++;
}
auto pdb = reinterpret_cast<PessimisticTransactionDB*>(db);
pdb->UnregisterTransaction(txn);
delete txn;
};
std::function<void(size_t)> txn_t3 = [&](size_t index) {
// A full 2pc txn that also involves a commit marker.
TransactionOptions txn_options;
WriteOptions write_options;
Transaction* txn = db->BeginTransaction(write_options, txn_options);
auto istr = std::to_string(index);
auto s = txn->SetName("xid" + istr);
ASSERT_OK(s);
s = txn->Put(Slice("foo" + istr), Slice("bar"));
s = txn->Put(Slice("foo2" + istr), Slice("bar2"));
s = txn->Put(Slice("foo3" + istr), Slice("bar3"));
s = txn->Put(Slice("foo4" + istr), Slice("bar4"));
s = txn->Put(Slice("foo5" + istr), Slice("bar5"));
ASSERT_OK(s);
expected_commits++;
s = txn->Prepare();
ASSERT_OK(s);
commit_writes++;
s = txn->Commit();
ASSERT_OK(s);
if (txn_db_options.write_policy == TxnDBWritePolicy::WRITE_COMMITTED) {
// Consume one seq per key
exp_seq += 5;
} else {
// Consume one seq per batch
exp_seq++;
// Consume one seq per commit marker
exp_seq++;
}
delete txn;
};
};
class MySQLStyleTransactionTest : public TransactionTest {};

505
utilities/transactions/write_prepared_transaction_test.cc
View file

@ -285,9 +285,10 @@ class WritePreparedTransactionTest : public TransactionTest {
}
};
// TODO(myabandeh): enable it for concurrent_prepare
INSTANTIATE_TEST_CASE_P(WritePreparedTransactionTest,
WritePreparedTransactionTest,
::testing::Values(std::make_tuple(false, true,
::testing::Values(std::make_tuple(false, false,
WRITE_PREPARED)));
TEST_P(WritePreparedTransactionTest, CommitMapTest) {
@ -552,95 +553,441 @@ TEST_P(WritePreparedTransactionTest, AdvanceMaxEvictedSeqBasicTest) {
}
}
// This test clarfies the existing expectation from the sequence number
// algorithm. It could detect mistakes in updating the code but it is not
// necessarily the one acceptable way. If the algorithm is legitimately changed,
// this unit test should be updated as well.
// TODO(myabandeh): remove this redundant test after transaction_test is enabled
// with WRITE_PREPARED too This test clarifies the existing expectation from the
// sequence number algorithm. It could detect mistakes in updating the code but
// it is not necessarily the one acceptable way. If the algorithm is
// legitimately changed, this unit test should be updated as well.
TEST_P(WritePreparedTransactionTest, SeqAdvanceTest) {
auto pdb = reinterpret_cast<PessimisticTransactionDB*>(db);
DBImpl* db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
auto seq = db_impl->GetLatestSequenceNumber();
auto exp_seq = seq;
// Test DB's internal txn. It involves no prepare phase nor a commit marker.
WriteOptions wopts;
auto s = db->Put(wopts, "key", "value");
// Consume one seq per batch
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
FlushOptions fopt;
// Doing it twice might detect some bugs
s = db->Put(wopts, "key", "value");
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Do the test with NUM_BRANCHES branches in it. Each run of a test takes some
// of the branches. This is the same as counting a binary number where i-th
// bit represents whether we take branch i in the represented by the number.
const size_t NUM_BRANCHES = 8;
// Helper function that shows if the branch is to be taken in the run
// represented by the number n.
auto branch_do = [&](size_t n, size_t* branch) {
assert(*branch < NUM_BRANCHES);
const size_t filter = static_cast<size_t>(1) << *branch;
return n & filter;
};
const size_t max_n = static_cast<size_t>(1) << NUM_BRANCHES;
for (size_t n = 0; n < max_n; n++, ReOpen()) {
DBImpl* db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
size_t branch = 0;
auto seq = db_impl->GetLatestSequenceNumber();
exp_seq = seq;
txn_t0(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Testing directly writing a write batch. Functionality-wise it is equivalent
// to commit without prepare.
WriteBatch wb;
wb.Put("k1", "v1");
wb.Put("k2", "v2");
wb.Put("k3", "v3");
s = pdb->Write(wopts, &wb);
// Consume one seq per batch
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
// Doing it twice might detect some bugs
txn_t0(1);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
txn_t1(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
txn_t3(0);
// Since commit marker does not write to memtable, the last seq number is
// not updated immediately. But the advance should be visible after the next
// write.
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
txn_t0(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
txn_t2(0);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
if (branch_do(n, &branch)) {
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
if (branch_do(n, &branch)) {
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
}
}
TEST_P(WritePreparedTransactionTest, SeqAdvanceConcurrentTest) {
// Given the sequential run of txns, with this timeout we should never see a
// deadlock nor a timeout unless we have a key conflict, which should be
// almost infeasible.
txn_db_options.transaction_lock_timeout = 1000;
txn_db_options.default_lock_timeout = 1000;
ReOpen();
FlushOptions fopt;
// Number of different txn types we use in this test
const size_t type_cnt = 4;
// The size of the first write group
// TODO(myabandeh): This should be increase for pre-release tests
const size_t first_group_size = 2;
// Total number of txns we run in each test
const size_t txn_cnt = first_group_size * 2;
size_t base[txn_cnt + 1] = {
1,
};
for (size_t bi = 1; bi <= txn_cnt; bi++) {
base[bi] = base[bi - 1] * type_cnt;
}
const size_t max_n = static_cast<size_t>(std::pow(type_cnt, txn_cnt));
printf("Number of cases being tested is %" PRIu64 "\n", max_n);
for (size_t n = 0; n < max_n; n++, ReOpen()) {
if (n % 1000 == 0) {
printf("Tested %" PRIu64 " cases so far\n", n);
}
DBImpl* db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
auto seq = db_impl->GetLatestSequenceNumber();
exp_seq = seq;
// This is increased before writing the batch for commit
commit_writes = 0;
// This is increased before txn starts linking if it expects to do a commit
// eventually
expected_commits = 0;
std::vector<port::Thread> threads;
linked = 0;
std::atomic<bool> batch_formed(false);
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"WriteThread::EnterAsBatchGroupLeader:End",
[&](void* arg) { batch_formed = true; });
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"WriteThread::JoinBatchGroup:Wait", [&](void* arg) {
linked++;
if (linked == 1) {
// Wait until the others are linked too.
while (linked < first_group_size) {
}
} else if (linked == 1 + first_group_size) {
// Make the 2nd batch of the rest of writes plus any followup
// commits from the first batch
while (linked < txn_cnt + commit_writes) {
}
}
// Then we will have one or more batches consisting of follow-up
// commits from the 2nd batch. There is a bit of non-determinism here
// but it should be tolerable.
});
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
for (size_t bi = 0; bi < txn_cnt; bi++) {
size_t d =
(n % base[bi + 1]) /
base[bi]; // get the bi-th digit in number system based on type_cnt
switch (d) {
case 0:
threads.emplace_back(txn_t0, bi);
break;
case 1:
threads.emplace_back(txn_t1, bi);
break;
case 2:
threads.emplace_back(txn_t2, bi);
break;
case 3:
threads.emplace_back(txn_t3, bi);
break;
default:
assert(false);
}
// wait to be linked
while (linked.load() <= bi) {
}
if (bi + 1 ==
first_group_size) { // after a queue of size first_group_size
while (!batch_formed) {
}
// to make it more deterministic, wait until the commits are linked
while (linked.load() <= bi + expected_commits) {
}
}
}
for (auto& t : threads) {
t.join();
}
if (txn_db_options.write_policy == WRITE_PREPARED) {
// In this case none of the above scheduling tricks to deterministically
// form merged bactches works because the writes go to saparte queues.
// This would result in different write groups in each run of the test. We
// still keep the test since althgouh non-deterministic and hard to debug,
// it is still useful to have. Since in this case we could finish with
// commit writes that dont write to memtable, the seq is not advanced in
// this code path. It will be after the next write. So we do one more
// write to make the impact of last seq visible.
txn_t0(0);
}
// Check if memtable inserts advanced seq number as expected
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
rocksdb::SyncPoint::GetInstance()->ClearAllCallBacks();
// Check if recovery preserves the last sequence number
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Check if flush preserves the last sequence number
db_impl->Flush(fopt);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
// Check if recovery after flush preserves the last sequence number
db_impl->FlushWAL(true);
ReOpenNoDelete();
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
}
}
// Run a couple of differnet txns among them some uncommitted. Restart the db at
// a couple points to check whether the list of uncommitted txns are recovered
// properly.
TEST_P(WritePreparedTransactionTest, BasicRecoveryTest) {
options.disable_auto_compactions = true;
ReOpen();
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
txn_t0(0);
// A full 2pc txn that also involves a commit marker.
TransactionOptions txn_options;
WriteOptions write_options;
Transaction* txn = db->BeginTransaction(write_options, txn_options);
s = txn->SetName("xid");
size_t index = 1000;
Transaction* txn0 = db->BeginTransaction(write_options, txn_options);
auto istr0 = std::to_string(index);
auto s = txn0->SetName("xid" + istr0);
ASSERT_OK(s);
s = txn->Put(Slice("foo"), Slice("bar"));
s = txn->Put(Slice("foo2"), Slice("bar2"));
s = txn->Put(Slice("foo3"), Slice("bar3"));
s = txn->Put(Slice("foo4"), Slice("bar4"));
s = txn->Put(Slice("foo5"), Slice("bar5"));
s = txn0->Put(Slice("foo0" + istr0), Slice("bar0" + istr0));
ASSERT_OK(s);
s = txn->Prepare();
ASSERT_OK(s);
// Consume one seq per batch
exp_seq++;
s = txn->Commit();
ASSERT_OK(s);
// Consume one seq per commit marker
exp_seq++;
// Since commit marker does not write to memtable, the last seq number is not
// updated immedaitely. But the advance should be visible after the next
// write.
s = txn0->Prepare();
auto prep_seq_0 = txn0->GetId();
s = db->Put(wopts, "key", "value");
// Consume one seq per batch
exp_seq++;
ASSERT_OK(s);
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
delete txn;
txn_t1(0);
// Commit without prepare. It shoudl write to DB without a commit marker.
txn = db->BeginTransaction(write_options, txn_options);
s = txn->SetName("xid2");
index++;
Transaction* txn1 = db->BeginTransaction(write_options, txn_options);
auto istr1 = std::to_string(index);
s = txn1->SetName("xid" + istr1);
ASSERT_OK(s);
s = txn->Put(Slice("foo"), Slice("bar"));
s = txn->Put(Slice("foo2"), Slice("bar2"));
s = txn->Put(Slice("foo3"), Slice("bar3"));
s = txn->Put(Slice("foo4"), Slice("bar4"));
s = txn->Put(Slice("foo5"), Slice("bar5"));
s = txn1->Put(Slice("foo1" + istr1), Slice("bar"));
ASSERT_OK(s);
s = txn->Commit();
s = txn1->Prepare();
auto prep_seq_1 = txn1->GetId();
txn_t2(0);
ReadOptions ropt;
PinnableSlice pinnable_val;
// Check the value is not committed before restart
s = db->Get(ropt, db->DefaultColumnFamily(), "foo0" + istr0, &pinnable_val);
ASSERT_TRUE(s.IsNotFound());
pinnable_val.Reset();
delete txn0;
delete txn1;
wp_db->db_impl_->FlushWAL(true);
ReOpenNoDelete();
wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
// After recovery, all the uncommitted txns (0 and 1) should be inserted into
// delayed_prepared_
ASSERT_TRUE(wp_db->prepared_txns_.empty());
ASSERT_FALSE(wp_db->delayed_prepared_empty_);
ASSERT_LE(prep_seq_0, wp_db->max_evicted_seq_);
ASSERT_LE(prep_seq_1, wp_db->max_evicted_seq_);
{
ReadLock rl(&wp_db->prepared_mutex_);
ASSERT_EQ(2, wp_db->delayed_prepared_.size());
ASSERT_TRUE(wp_db->delayed_prepared_.find(prep_seq_0) !=
wp_db->delayed_prepared_.end());
ASSERT_TRUE(wp_db->delayed_prepared_.find(prep_seq_1) !=
wp_db->delayed_prepared_.end());
}
// Check the value is still not committed after restart
s = db->Get(ropt, db->DefaultColumnFamily(), "foo0" + istr0, &pinnable_val);
ASSERT_TRUE(s.IsNotFound());
pinnable_val.Reset();
txn_t3(0);
// Test that a recovered txns will be properly marked committed for the next
// recovery
txn1 = db->GetTransactionByName("xid" + istr1);
ASSERT_NE(txn1, nullptr);
txn1->Commit();
index++;
Transaction* txn2 = db->BeginTransaction(write_options, txn_options);
auto istr2 = std::to_string(index);
s = txn2->SetName("xid" + istr2);
ASSERT_OK(s);
// Consume one seq per batch
exp_seq++;
seq = db_impl->GetLatestSequenceNumber();
ASSERT_EQ(exp_seq, seq);
pdb->UnregisterTransaction(txn);
delete txn;
s = txn2->Put(Slice("foo2" + istr2), Slice("bar"));
ASSERT_OK(s);
s = txn2->Prepare();
auto prep_seq_2 = txn2->GetId();
delete txn2;
wp_db->db_impl_->FlushWAL(true);
ReOpenNoDelete();
wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
ASSERT_TRUE(wp_db->prepared_txns_.empty());
ASSERT_FALSE(wp_db->delayed_prepared_empty_);
// 0 and 2 are prepared and 1 is committed
{
ReadLock rl(&wp_db->prepared_mutex_);
ASSERT_EQ(2, wp_db->delayed_prepared_.size());
const auto& end = wp_db->delayed_prepared_.end();
ASSERT_NE(wp_db->delayed_prepared_.find(prep_seq_0), end);
ASSERT_EQ(wp_db->delayed_prepared_.find(prep_seq_1), end);
ASSERT_NE(wp_db->delayed_prepared_.find(prep_seq_2), end);
}
ASSERT_LE(prep_seq_0, wp_db->max_evicted_seq_);
ASSERT_LE(prep_seq_2, wp_db->max_evicted_seq_);
// Commit all the remaining txns
txn0 = db->GetTransactionByName("xid" + istr0);
ASSERT_NE(txn0, nullptr);
txn0->Commit();
txn2 = db->GetTransactionByName("xid" + istr2);
ASSERT_NE(txn2, nullptr);
txn2->Commit();
// Check the value is committed after commit
s = db->Get(ropt, db->DefaultColumnFamily(), "foo0" + istr0, &pinnable_val);
ASSERT_TRUE(s.ok());
ASSERT_TRUE(pinnable_val == ("bar0" + istr0));
pinnable_val.Reset();
delete txn0;
delete txn2;
wp_db->db_impl_->FlushWAL(true);
ReOpenNoDelete();
wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
ASSERT_TRUE(wp_db->prepared_txns_.empty());
ASSERT_TRUE(wp_db->delayed_prepared_empty_);
// Check the value is still committed after recovery
s = db->Get(ropt, db->DefaultColumnFamily(), "foo0" + istr0, &pinnable_val);
ASSERT_TRUE(s.ok());
ASSERT_TRUE(pinnable_val == ("bar0" + istr0));
pinnable_val.Reset();
}
// After recovery the new transactions should still conflict with recovered
// transactions.
TEST_P(WritePreparedTransactionTest, ConflictDetectionAfterRecoveryTest) {
options.disable_auto_compactions = true;
ReOpen();
TransactionOptions txn_options;
WriteOptions write_options;
size_t index = 0;
Transaction* txn0 = db->BeginTransaction(write_options, txn_options);
auto istr0 = std::to_string(index);
auto s = txn0->SetName("xid" + istr0);
ASSERT_OK(s);
s = txn0->Put(Slice("key" + istr0), Slice("bar0" + istr0));
ASSERT_OK(s);
s = txn0->Prepare();
// With the same index 0 and key prefix, txn_t0 should conflict with txn0
txn_t0_with_status(0, Status::TimedOut());
delete txn0;
auto db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
db_impl->FlushWAL(true);
ReOpenNoDelete();
// It should still conflict after the recovery
txn_t0_with_status(0, Status::TimedOut());
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
db_impl->FlushWAL(true);
ReOpenNoDelete();
// Check that a recovered txn will still cause conflicts after 2nd recovery
txn_t0_with_status(0, Status::TimedOut());
txn0 = db->GetTransactionByName("xid" + istr0);
ASSERT_NE(txn0, nullptr);
txn0->Commit();
delete txn0;
db_impl = reinterpret_cast<DBImpl*>(db->GetRootDB());
db_impl->FlushWAL(true);
ReOpenNoDelete();
// tnx0 is now committed and should no longer cause a conflict
txn_t0_with_status(0, Status::OK());
}
// After recovery the commit map is empty while the max is set. The code would
// go through a different path which requires a separate test.
TEST_P(WritePreparedTransactionTest, IsInSnapshotEmptyMapTest) {
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
wp_db->max_evicted_seq_ = 100;
ASSERT_FALSE(wp_db->IsInSnapshot(50, 40));
ASSERT_TRUE(wp_db->IsInSnapshot(50, 50));
ASSERT_TRUE(wp_db->IsInSnapshot(50, 100));
ASSERT_TRUE(wp_db->IsInSnapshot(50, 150));
ASSERT_FALSE(wp_db->IsInSnapshot(100, 80));
ASSERT_TRUE(wp_db->IsInSnapshot(100, 100));
ASSERT_TRUE(wp_db->IsInSnapshot(100, 150));
}
// Test WritePreparedTxnDB's IsInSnapshot against different ordering of
@ -683,6 +1030,8 @@ TEST_P(WritePreparedTransactionTest, IsInSnapshotTest) {
// We keep the list of txns comitted before we take the last snaphot.
// These should be the only seq numbers that will be found in the snapshot
std::set<uint64_t> committed_before;
// The set of commit seq numbers to be excluded from IsInSnapshot queries
std::set<uint64_t> commit_seqs;
DBImpl* mock_db = new DBImpl(options, dbname);
std::unique_ptr<WritePreparedTxnDBMock> wp_db(new WritePreparedTxnDBMock(
mock_db, txn_db_options, snapshot_cache_bits, commit_cache_bits));
@ -701,6 +1050,7 @@ TEST_P(WritePreparedTransactionTest, IsInSnapshotTest) {
} else { // else commit it
seq++;
wp_db->AddCommitted(cur_txn, seq);
commit_seqs.insert(seq);
if (!snapshot) {
committed_before.insert(cur_txn);
}
@ -725,7 +1075,8 @@ TEST_P(WritePreparedTransactionTest, IsInSnapshotTest) {
// it at each cycle to test that the system is still sound when
// max_evicted_seq_ advances.
if (snapshot) {
for (uint64_t s = 0; s <= seq; s++) {
for (uint64_t s = 1;
s <= seq && commit_seqs.find(s) == commit_seqs.end(); s++) {
bool was_committed =
(committed_before.find(s) != committed_before.end());
bool is_in_snapshot = wp_db->IsInSnapshot(s, snapshot);

20
utilities/transactions/write_prepared_txn.cc
View file

@ -52,8 +52,9 @@ Status WritePreparedTxn::PrepareInternal() {
/*callback*/ nullptr, &log_number_, /*log ref*/ 0,
!disable_memtable, &seq_used);
assert(seq_used != kMaxSequenceNumber);
prepare_seq_ = seq_used;
wpt_db_->AddPrepared(prepare_seq_);
auto prepare_seq = seq_used;
SetId(prepare_seq);
wpt_db_->AddPrepared(prepare_seq);
return s;
}
@ -66,9 +67,10 @@ Status WritePreparedTxn::CommitBatchInternal(WriteBatch* batch) {
WriteBatchInternal::InsertNoop(batch);
const bool disable_memtable = true;
const uint64_t no_log_ref = 0;
uint64_t seq_used;
uint64_t seq_used = kMaxSequenceNumber;
auto s = db_impl_->WriteImpl(write_options_, batch, nullptr, nullptr,
no_log_ref, !disable_memtable, &seq_used);
assert(seq_used != kMaxSequenceNumber);
uint64_t& prepare_seq = seq_used;
uint64_t& commit_seq = seq_used;
// TODO(myabandeh): skip AddPrepared
@ -90,13 +92,19 @@ Status WritePreparedTxn::CommitInternal() {
working_batch->MarkWalTerminationPoint();
const bool disable_memtable = true;
uint64_t seq_used;
uint64_t seq_used = kMaxSequenceNumber;
// Since the prepared batch is directly written to memtable, there is already
// a connection between the memtable and its WAL, so there is no need to
// redundantly reference the log that contains the prepared data.
const uint64_t zero_log_number = 0ull;
auto s = db_impl_->WriteImpl(write_options_, working_batch, nullptr, nullptr,
log_number_, disable_memtable, &seq_used);
zero_log_number, disable_memtable, &seq_used);
assert(seq_used != kMaxSequenceNumber);
uint64_t& commit_seq = seq_used;
// TODO(myabandeh): Reject a commit request if AddCommitted cannot encode
// commit_seq. This happens if prep_seq <<< commit_seq.
wpt_db_->AddCommitted(prepare_seq_, commit_seq);
auto prepare_seq = GetId();
wpt_db_->AddCommitted(prepare_seq, commit_seq);
return s;
}

3
utilities/transactions/write_prepared_txn.h
View file

@ -53,6 +53,8 @@ class WritePreparedTxn : public PessimisticTransaction {
Status Rollback() override;
private:
friend class WritePreparedTransactionTest_BasicRecoveryTest_Test;
Status PrepareInternal() override;
Status CommitWithoutPrepareInternal() override;
@ -73,7 +75,6 @@ class WritePreparedTxn : public PessimisticTransaction {
void operator=(const WritePreparedTxn&);
WritePreparedTxnDB* wpt_db_;
uint64_t prepare_seq_;
};
} // namespace rocksdb