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Add more unit test to write_prepared txns

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Summary: Closes https://github.com/facebook/rocksdb/pull/2798

Differential Revision: D5724173

Pulled By: maysamyabandeh

fbshipit-source-id: fb6b782d933fb4be315b1a231a6a67a66fdc9c96
This commit is contained in:
Maysam Yabandeh 2017-08-31 09:27:14 -07:00 committed by Facebook Github Bot
parent 06b37eef7b
commit 26ac24f199
11 changed files with 945 additions and 366 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
.travis.yml
View File

@ -21,6 +21,7 @@ env:
- TEST_GROUP=platform_dependent # 16-18 minutes
- TEST_GROUP=1 # 33-35 minutes
- TEST_GROUP=2 # 30-32 minutes
- TEST_GROUP=3 # ? minutes - under development
# Run java tests
- JOB_NAME=java_test # 4-11 minutes
# Build ROCKSDB_LITE
@ -36,6 +37,8 @@ matrix:
env: TEST_GROUP=1
- os: osx
env: TEST_GROUP=2
- os: osx
env: TEST_GROUP=3
- os : osx
env: JOB_NAME=cmake-mingw
- os : linux
@ -59,7 +62,8 @@ script:
- ${CXX} --version
- if [ "${TEST_GROUP}" == 'platform_dependent' ]; then ccache -C && OPT=-DTRAVIS V=1 ROCKSDBTESTS_END=db_block_cache_test make -j4 all_but_some_tests check_some; fi
- if [ "${TEST_GROUP}" == '1' ]; then OPT=-DTRAVIS V=1 ROCKSDBTESTS_START=db_block_cache_test ROCKSDBTESTS_END=comparator_db_test make -j4 check_some; fi
- if [ "${TEST_GROUP}" == '2' ]; then OPT=-DTRAVIS V=1 ROCKSDBTESTS_START=comparator_db_test make -j4 check_some; fi
- if [ "${TEST_GROUP}" == '2' ]; then OPT=-DTRAVIS V=1 ROCKSDBTESTS_START=comparator_db_test ROCKSDBTESTS_END=write_prepared_transaction_test make -j4 check_some; fi
- if [ "${TEST_GROUP}" == '3' ]; then OPT=-DTRAVIS V=1 ROCKSDBTESTS_START=write_prepared_transaction_test make -j4 check_some; fi
- if [ "${JOB_NAME}" == 'java_test' ]; then OPT=-DTRAVIS V=1 make clean jclean && make rocksdbjava jtest; fi
- if [ "${JOB_NAME}" == 'lite_build' ]; then OPT="-DTRAVIS -DROCKSDB_LITE" V=1 make -j4 static_lib; fi
- if [ "${JOB_NAME}" == 'examples' ]; then OPT=-DTRAVIS V=1 make -j4 static_lib; cd examples; make -j4; fi

1
CMakeLists.txt
View File

@ -830,6 +830,7 @@ if(WITH_TESTS)
utilities/table_properties_collectors/compact_on_deletion_collector_test.cc
utilities/transactions/optimistic_transaction_test.cc
utilities/transactions/transaction_test.cc
utilities/transactions/write_prepared_transaction_test.cc
utilities/ttl/ttl_test.cc
utilities/write_batch_with_index/write_batch_with_index_test.cc
)

7
Makefile
View File

@ -476,6 +476,7 @@ TESTS = \
object_registry_test \
repair_test \
env_timed_test \
write_prepared_transaction_test \
PARALLEL_TEST = \
backupable_db_test \
@ -491,7 +492,8 @@ PARALLEL_TEST = \
manual_compaction_test \
persistent_cache_test \
table_test \
transaction_test
transaction_test \
write_prepared_transaction_test
SUBSET := $(TESTS)
ifdef ROCKSDBTESTS_START
@ -1392,6 +1394,9 @@ heap_test: util/heap_test.o $(GTEST)
transaction_test: utilities/transactions/transaction_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(AM_LINK)
write_prepared_transaction_test: utilities/transactions/write_prepared_transaction_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(AM_LINK)
sst_dump: tools/sst_dump.o $(LIBOBJECTS)
$(AM_LINK)

10
TARGETS
View File

@ -15,7 +15,6 @@ rocksdb_compiler_flags = [
"-DROCKSDB_SCHED_GETCPU_PRESENT",
"-DROCKSDB_SUPPORT_THREAD_LOCAL",
"-DOS_LINUX",
"-DROCKSDB_UBSAN_RUN",
# Flags to enable libs we include
"-DSNAPPY",
"-DZLIB",
@ -476,7 +475,9 @@ ROCKS_TESTS = [['arena_test', 'util/arena_test.cc', 'serial'],
['thread_list_test', 'util/thread_list_test.cc', 'serial'],
['thread_local_test', 'util/thread_local_test.cc', 'serial'],
['timer_queue_test', 'util/timer_queue_test.cc', 'serial'],
['transaction_test', 'utilities/transactions/transaction_test.cc', 'serial'],
['transaction_test',
'utilities/transactions/transaction_test.cc',
'parallel'],
['ttl_test', 'utilities/ttl/ttl_test.cc', 'serial'],
['util_merge_operators_test',
'utilities/util_merge_operators_test.cc',
@ -493,7 +494,10 @@ ROCKS_TESTS = [['arena_test', 'util/arena_test.cc', 'serial'],
'memtable/write_buffer_manager_test.cc',
'serial'],
['write_callback_test', 'db/write_callback_test.cc', 'serial'],
['write_controller_test', 'db/write_controller_test.cc', 'serial']]
['write_controller_test', 'db/write_controller_test.cc', 'serial'],
['write_prepared_transaction_test',
'utilities/transactions/write_prepared_transaction_test.cc',
'serial']]
# Generate a test rule for each entry in ROCKS_TESTS

1
src.mk
View File

@ -354,6 +354,7 @@ MAIN_SOURCES = \
utilities/table_properties_collectors/compact_on_deletion_collector_test.cc \
utilities/transactions/optimistic_transaction_test.cc \
utilities/transactions/transaction_test.cc \
utilities/transactions/write_prepared_transaction_test.cc \
utilities/ttl/ttl_test.cc \
utilities/write_batch_with_index/write_batch_with_index_test.cc \

3
util/sync_point.h
View File

@ -46,6 +46,7 @@ extern void TestKillRandom(std::string kill_point, int odds,
#ifdef NDEBUG
#define TEST_SYNC_POINT(x)
#define TEST_IDX_SYNC_POINT(x, index)
#define TEST_SYNC_POINT_CALLBACK(x, y)
#else
@ -135,6 +136,8 @@ class SyncPoint {
// See TransactionLogIteratorRace in db_test.cc for an example use case.
// TEST_SYNC_POINT is no op in release build.
#define TEST_SYNC_POINT(x) rocksdb::SyncPoint::GetInstance()->Process(x)
#define TEST_IDX_SYNC_POINT(x, index) \
rocksdb::SyncPoint::GetInstance()->Process(x + std::to_string(index))
#define TEST_SYNC_POINT_CALLBACK(x, y) \
rocksdb::SyncPoint::GetInstance()->Process(x, y)
#endif // NDEBUG

283
utilities/transactions/pessimistic_transaction_db.cc
View File

@ -22,6 +22,7 @@
#include "rocksdb/utilities/transaction_db.h"
#include "util/cast_util.h"
#include "util/mutexlock.h"
#include "util/sync_point.h"
#include "utilities/transactions/pessimistic_transaction.h"
#include "utilities/transactions/transaction_db_mutex_impl.h"
@ -605,121 +606,11 @@ void WritePreparedTxnDB::AddCommitted(uint64_t prepare_seq,
if (prev_max < evicted.commit_seq) {
// TODO(myabandeh) inc max in larger steps to avoid frequent updates
auto max_evicted_seq = evicted.commit_seq;
// When max_evicted_seq_ advances, move older entries from prepared_txns_
// to delayed_prepared_. This guarantees that if a seq is lower than max,
// then it is not in prepared_txns_ ans save an expensive, synchronized
// lookup from a shared set. delayed_prepared_ is expected to be empty in
// normal cases.
{
WriteLock wl(&prepared_mutex_);
while (!prepared_txns_.empty() &&
prepared_txns_.top() <= max_evicted_seq) {
auto to_be_popped = prepared_txns_.top();
delayed_prepared_.insert(to_be_popped);
prepared_txns_.pop();
delayed_prepared_empty_.store(false, std::memory_order_release);
}
}
// With each change to max_evicted_seq_ fetch the live snapshots behind it
SequenceNumber curr_seq;
std::vector<SequenceNumber> all_snapshots;
bool update_snapshots = false;
{
InstrumentedMutex(db_impl_->mutex());
// We use this to identify how fresh are the snapshot list. Since this
// is done atomically with obtaining the snapshot list, the one with
// the larger seq is more fresh. If the seq is equal the full snapshot
// list could be different since taking snapshots does not increase
// the db seq. However since we only care about snapshots before the
// new max, such recent snapshots would not be included the in the
// list anyway.
curr_seq = db_impl_->GetLatestSequenceNumber();
if (curr_seq > snapshots_version_) {
// This is to avoid updating the snapshots_ if it already updated
// with a more recent vesion by a concrrent thread
update_snapshots = true;
// We only care about snapshots lower then max
all_snapshots =
db_impl_->snapshots().GetAll(nullptr, max_evicted_seq);
}
}
if (update_snapshots) {
WriteLock wl(&snapshots_mutex_);
snapshots_version_ = curr_seq;
// We update the list concurrently with the readers.
// Both new and old lists are sorted and the new list is subset of the
// previous list plus some new items. Thus if a snapshot repeats in
// both new and old lists, it will appear upper in the new list. So if
// we simply insert the new snapshots in order, if an overwritten item
// is still valid in the new list is either written to the same place in
// the array or it is written in a higher palce before it gets
// overwritten by another item. This guarantess a reader that reads the
// list bottom-up will eventaully see a snapshot that repeats in the
// update, either before it gets overwritten by the writer or
// afterwards.
size_t i = 0;
auto it = all_snapshots.begin();
for (; it != all_snapshots.end() && i < SNAPSHOT_CACHE_SIZE;
it++, i++) {
snapshot_cache_[i].store(*it, std::memory_order_release);
}
snapshots_.clear();
for (; it != all_snapshots.end(); it++) {
// Insert them to a vector that is less efficient to access
// concurrently
snapshots_.push_back(*it);
}
// Update the size at the end. Otherwise a parallel reader might read
// items that are not set yet.
snapshots_total_.store(all_snapshots.size(), std::memory_order_release);
}
while (prev_max < max_evicted_seq &&
!max_evicted_seq_.compare_exchange_weak(
prev_max, max_evicted_seq, std::memory_order_release,
std::memory_order_acquire)) {
};
AdvanceMaxEvictedSeq(prev_max, max_evicted_seq);
}
// After each eviction from commit cache, check if the commit entry should
// be kept around because it overlaps with a live snapshot.
// First check the snapshot cache that is efficient for concurrent access
auto cnt = snapshots_total_.load(std::memory_order_acquire);
// The list might get updated concurrently as we are reading from it. The
// reader should be able to read all the snapshots that are still valid
// after the update. Since the survived snapshots are written in a higher
// place before gets overwritten the reader that reads bottom-up will
// eventully see it.
const bool next_is_larger = true;
SequenceNumber snapshot_seq = kMaxSequenceNumber;
size_t ip1 = std::min(cnt, SNAPSHOT_CACHE_SIZE);
for (; 0 < ip1; ip1--) {
snapshot_seq = snapshot_cache_[ip1 - 1].load(std::memory_order_acquire);
if (!MaybeUpdateOldCommitMap(evicted.prep_seq, evicted.commit_seq,
snapshot_seq, !next_is_larger)) {
break;
}
}
if (UNLIKELY(SNAPSHOT_CACHE_SIZE < cnt && ip1 == SNAPSHOT_CACHE_SIZE &&
snapshot_seq < evicted.prep_seq)) {
// Then access the less efficient list of snapshots_
ReadLock rl(&snapshots_mutex_);
// Items could have moved from the snapshots_ to snapshot_cache_ before
// accquiring the lock. To make sure that we do not miss a valid snapshot,
// read snapshot_cache_ again while holding the lock.
for (size_t i = 0; i < SNAPSHOT_CACHE_SIZE; i++) {
snapshot_seq = snapshot_cache_[i].load(std::memory_order_acquire);
if (!MaybeUpdateOldCommitMap(evicted.prep_seq, evicted.commit_seq,
snapshot_seq, next_is_larger)) {
break;
}
}
for (auto snapshot_seq_2 : snapshots_) {
if (!MaybeUpdateOldCommitMap(evicted.prep_seq, evicted.commit_seq,
snapshot_seq_2, next_is_larger)) {
break;
}
}
}
CheckAgainstSnapshots(evicted);
}
bool succ =
ExchangeCommitEntry(indexed_seq, evicted, {prepare_seq, commit_seq});
@ -744,7 +635,7 @@ void WritePreparedTxnDB::AddCommitted(uint64_t prepare_seq,
}
}
bool WritePreparedTxnDB::GetCommitEntry(uint64_t indexed_seq,
bool WritePreparedTxnDB::GetCommitEntry(const uint64_t indexed_seq,
CommitEntry* entry) {
// TODO(myabandeh): implement lock-free commit_cache_
ReadLock rl(&commit_cache_mutex_);
@ -752,8 +643,8 @@ bool WritePreparedTxnDB::GetCommitEntry(uint64_t indexed_seq,
return (entry->commit_seq != 0); // initialized
}
bool WritePreparedTxnDB::AddCommitEntry(uint64_t indexed_seq,
CommitEntry& new_entry,
bool WritePreparedTxnDB::AddCommitEntry(const uint64_t indexed_seq,
const CommitEntry& new_entry,
CommitEntry* evicted_entry) {
// TODO(myabandeh): implement lock-free commit_cache_
WriteLock wl(&commit_cache_mutex_);
@ -762,9 +653,9 @@ bool WritePreparedTxnDB::AddCommitEntry(uint64_t indexed_seq,
return (evicted_entry->commit_seq != 0); // initialized
}
bool WritePreparedTxnDB::ExchangeCommitEntry(uint64_t indexed_seq,
CommitEntry& expected_entry,
CommitEntry new_entry) {
bool WritePreparedTxnDB::ExchangeCommitEntry(const uint64_t indexed_seq,
const CommitEntry& expected_entry,
const CommitEntry& new_entry) {
// TODO(myabandeh): implement lock-free commit_cache_
WriteLock wl(&commit_cache_mutex_);
auto& evicted_entry = commit_cache_[indexed_seq];
@ -775,11 +666,167 @@ bool WritePreparedTxnDB::ExchangeCommitEntry(uint64_t indexed_seq,
return true;
}
void WritePreparedTxnDB::AdvanceMaxEvictedSeq(SequenceNumber& prev_max,
SequenceNumber& new_max) {
// When max_evicted_seq_ advances, move older entries from prepared_txns_
// to delayed_prepared_. This guarantees that if a seq is lower than max,
// then it is not in prepared_txns_ ans save an expensive, synchronized
// lookup from a shared set. delayed_prepared_ is expected to be empty in
// normal cases.
{
WriteLock wl(&prepared_mutex_);
while (!prepared_txns_.empty() && prepared_txns_.top() <= new_max) {
auto to_be_popped = prepared_txns_.top();
delayed_prepared_.insert(to_be_popped);
prepared_txns_.pop();
delayed_prepared_empty_.store(false, std::memory_order_release);
}
}
// With each change to max_evicted_seq_ fetch the live snapshots behind it
SequenceNumber curr_seq;
std::vector<SequenceNumber> snapshots;
bool update_snapshots = false;
{
InstrumentedMutex(db_impl_->mutex());
// We use this to identify how fresh are the snapshot list. Since this
// is done atomically with obtaining the snapshot list, the one with
// the larger seq is more fresh. If the seq is equal the full snapshot
// list could be different since taking snapshots does not increase
// the db seq. However since we only care about snapshots before the
// new max, such recent snapshots would not be included the in the
// list anyway.
curr_seq = db_impl_->GetLatestSequenceNumber();
if (curr_seq > snapshots_version_) {
// This is to avoid updating the snapshots_ if it already updated
// with a more recent vesion by a concrrent thread
update_snapshots = true;
// We only care about snapshots lower then max
snapshots = db_impl_->snapshots().GetAll(nullptr, new_max);
}
}
if (update_snapshots) {
UpdateSnapshots(snapshots, curr_seq);
}
// TODO(myabandeh): check if it worked with relaxed ordering
while (prev_max < new_max && !max_evicted_seq_.compare_exchange_weak(
prev_max, new_max, std::memory_order_release,
std::memory_order_acquire)) {
};
}
// 10m entry, 80MB size
size_t WritePreparedTxnDB::DEF_COMMIT_CACHE_SIZE = static_cast<size_t>(1 << 21);
size_t WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE =
static_cast<size_t>(1 << 7);
void WritePreparedTxnDB::UpdateSnapshots(
const std::vector<SequenceNumber>& snapshots,
const SequenceNumber& version) {
TEST_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:p:start");
TEST_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:s:start");
#ifndef NDEBUG
size_t sync_i = 0;
#endif
WriteLock wl(&snapshots_mutex_);
snapshots_version_ = version;
// We update the list concurrently with the readers.
// Both new and old lists are sorted and the new list is subset of the
// previous list plus some new items. Thus if a snapshot repeats in
// both new and old lists, it will appear upper in the new list. So if
// we simply insert the new snapshots in order, if an overwritten item
// is still valid in the new list is either written to the same place in
// the array or it is written in a higher palce before it gets
// overwritten by another item. This guarantess a reader that reads the
// list bottom-up will eventaully see a snapshot that repeats in the
// update, either before it gets overwritten by the writer or
// afterwards.
size_t i = 0;
auto it = snapshots.begin();
for (; it != snapshots.end() && i < SNAPSHOT_CACHE_SIZE; it++, i++) {
snapshot_cache_[i].store(*it, std::memory_order_release);
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:p:", ++sync_i);
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:s:", sync_i);
}
#ifndef NDEBUG
// Release the remaining sync points since they are useless given that the
// reader would also use lock to access snapshots
for (++sync_i; sync_i <= 10; ++sync_i) {
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:p:", sync_i);
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:s:", sync_i);
}
#endif
snapshots_.clear();
for (; it != snapshots.end(); it++) {
// Insert them to a vector that is less efficient to access
// concurrently
snapshots_.push_back(*it);
}
// Update the size at the end. Otherwise a parallel reader might read
// items that are not set yet.
snapshots_total_.store(snapshots.size(), std::memory_order_release);
TEST_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:p:end");
TEST_SYNC_POINT("WritePreparedTxnDB::UpdateSnapshots:s:end");
}
void WritePreparedTxnDB::CheckAgainstSnapshots(const CommitEntry& evicted) {
TEST_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:p:start");
TEST_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:s:start");
#ifndef NDEBUG
size_t sync_i = 0;
#endif
// First check the snapshot cache that is efficient for concurrent access
auto cnt = snapshots_total_.load(std::memory_order_acquire);
// The list might get updated concurrently as we are reading from it. The
// reader should be able to read all the snapshots that are still valid
// after the update. Since the survived snapshots are written in a higher
// place before gets overwritten the reader that reads bottom-up will
// eventully see it.
const bool next_is_larger = true;
SequenceNumber snapshot_seq = kMaxSequenceNumber;
size_t ip1 = std::min(cnt, SNAPSHOT_CACHE_SIZE);
for (; 0 < ip1; ip1--) {
snapshot_seq = snapshot_cache_[ip1 - 1].load(std::memory_order_acquire);
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:p:",
++sync_i);
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:s:", sync_i);
if (!MaybeUpdateOldCommitMap(evicted.prep_seq, evicted.commit_seq,
snapshot_seq, !next_is_larger)) {
break;
}
}
#ifndef NDEBUG
// Release the remaining sync points before accquiring the lock
for (++sync_i; sync_i <= 10; ++sync_i) {
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:p:", sync_i);
TEST_IDX_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:s:", sync_i);
}
#endif
TEST_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:p:end");
TEST_SYNC_POINT("WritePreparedTxnDB::CheckAgainstSnapshots:s:end");
if (UNLIKELY(SNAPSHOT_CACHE_SIZE < cnt && ip1 == SNAPSHOT_CACHE_SIZE &&
snapshot_seq < evicted.prep_seq)) {
// Then access the less efficient list of snapshots_
ReadLock rl(&snapshots_mutex_);
// Items could have moved from the snapshots_ to snapshot_cache_ before
// accquiring the lock. To make sure that we do not miss a valid snapshot,
// read snapshot_cache_ again while holding the lock.
for (size_t i = 0; i < SNAPSHOT_CACHE_SIZE; i++) {
snapshot_seq = snapshot_cache_[i].load(std::memory_order_acquire);
if (!MaybeUpdateOldCommitMap(evicted.prep_seq, evicted.commit_seq,
snapshot_seq, next_is_larger)) {
break;
}
}
for (auto snapshot_seq_2 : snapshots_) {
if (!MaybeUpdateOldCommitMap(evicted.prep_seq, evicted.commit_seq,
snapshot_seq_2, next_is_larger)) {
break;
}
}
}
}
bool WritePreparedTxnDB::MaybeUpdateOldCommitMap(
const uint64_t& prep_seq, const uint64_t& commit_seq,
const uint64_t& snapshot_seq, const bool next_is_larger = true) {

49
utilities/transactions/pessimistic_transaction_db.h
View File

@ -109,6 +109,9 @@ class PessimisticTransactionDB : public TransactionDB {
uint64_t commit_seq;
CommitEntry() : prep_seq(0), commit_seq(0) {}
CommitEntry(uint64_t ps, uint64_t cs) : prep_seq(ps), commit_seq(cs) {}
bool operator==(const CommitEntry& rhs) const {
return prep_seq == rhs.prep_seq && commit_seq == rhs.commit_seq;
}
};
protected:
@ -196,6 +199,11 @@ class WritePreparedTxnDB : public PessimisticTransactionDB {
private:
friend class WritePreparedTransactionTest_IsInSnapshotTest_Test;
friend class WritePreparedTransactionTest_CheckAgainstSnapshotsTest_Test;
friend class WritePreparedTransactionTest_CommitMapTest_Test;
friend class WritePreparedTransactionTest_SnapshotConcurrentAccessTest_Test;
friend class WritePreparedTransactionTest;
friend class PreparedHeap_BasicsTest_Test;
void init(const TransactionDBOptions& /* unused */) {
snapshot_cache_ = unique_ptr<std::atomic<SequenceNumber>[]>(
@ -223,13 +231,16 @@ class WritePreparedTxnDB : public PessimisticTransactionDB {
heap_.pop();
erased_heap_.pop();
}
while (heap_.empty() && !erased_heap_.empty()) {
erased_heap_.pop();
}
}
void erase(uint64_t seq) {
if (!heap_.empty()) {
if (seq < heap_.top()) {
// Already popped, ignore it.
} else if (heap_.top() == seq) {
heap_.pop();
pop();
} else { // (heap_.top() > seq)
// Down the heap, remember to pop it later
erased_heap_.push(seq);
@ -240,17 +251,45 @@ class WritePreparedTxnDB : public PessimisticTransactionDB {
// Get the commit entry with index indexed_seq from the commit table. It
// returns true if such entry exists.
bool GetCommitEntry(uint64_t indexed_seq, CommitEntry* entry);
bool GetCommitEntry(const uint64_t indexed_seq, CommitEntry* entry);
// Rewrite the entry with the index indexed_seq in the commit table with the
// commit entry <prep_seq, commit_seq>. If the rewrite results into eviction,
// sets the evicted_entry and returns true.
bool AddCommitEntry(uint64_t indexed_seq, CommitEntry& new_entry,
bool AddCommitEntry(const uint64_t indexed_seq, const CommitEntry& new_entry,
CommitEntry* evicted_entry);
// Rewrite the entry with the index indexed_seq in the commit table with the
// commit entry new_entry only if the existing entry matches the
// expected_entry. Returns false otherwise.
bool ExchangeCommitEntry(uint64_t indexed_seq, CommitEntry& expected_entry,
CommitEntry new_entry);
bool ExchangeCommitEntry(const uint64_t indexed_seq,
const CommitEntry& expected_entry,
const CommitEntry& new_entry);
// Increase max_evicted_seq_ from the previous value prev_max to the new
// value. This also involves taking care of prepared txns that are not
// committed before new_max, as well as updating the list of live snapshots at
// the time of updating the max. Thread-safety: this function can be called
// concurrently. The concurrent invocations of this function is equivalent to
// a serial invocation in which the last invocation is the one with the
// largetst new_max value.
void AdvanceMaxEvictedSeq(SequenceNumber& prev_max, SequenceNumber& new_max);
// Update the list of snapshots corresponding to the soon-to-be-updated
// max_eviceted_seq_. Thread-safety: this function can be called concurrently.
// The concurrent invocations of this function is equivalent to a serial
// invocation in which the last invocation is the one with the largetst
// version value.
void UpdateSnapshots(const std::vector<SequenceNumber>& snapshots,
const SequenceNumber& version);
// Check an evicted entry against live snapshots to see if it should be kept
// around or it can be safely discarded (and hence assume committed for all
// snapshots). Thread-safety: this function can be called concurrently. If it
// is called concurrently with multiple UpdateSnapshots, the result is the
// same as checking the intersection of the snapshot list before updates with
// the snapshot list of all the concurrent updates.
void CheckAgainstSnapshots(const CommitEntry& evicted);
// Add a new entry to old_commit_map_ if prep_seq <= snapshot_seq <
// commit_seq. Return false if checking the next snapshot(s) is not needed.

251
utilities/transactions/transaction_test.cc
View File

@ -9,7 +9,8 @@
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include "utilities/transactions/transaction_test.h"
#include <algorithm>
#include <functional>
#include <string>
@ -38,114 +39,20 @@ using std::string;
namespace rocksdb {
class TransactionTest : public ::testing::TestWithParam<
std::tuple<bool, bool, TxnDBWritePolicy>> {
public:
TransactionDB* db;
FaultInjectionTestEnv* env;
string dbname;
Options options;
TransactionDBOptions txn_db_options;
TransactionTest() {
options.create_if_missing = true;
options.max_write_buffer_number = 2;
options.write_buffer_size = 4 * 1024;
options.level0_file_num_compaction_trigger = 2;
options.merge_operator = MergeOperators::CreateFromStringId("stringappend");
env = new FaultInjectionTestEnv(Env::Default());
options.env = env;
options.concurrent_prepare = std::get<1>(GetParam());
dbname = test::TmpDir() + "/transaction_testdb";
DestroyDB(dbname, options);
txn_db_options.transaction_lock_timeout = 0;
txn_db_options.default_lock_timeout = 0;
txn_db_options.write_policy = std::get<2>(GetParam());
Status s;
if (std::get<0>(GetParam()) == false) {
s = TransactionDB::Open(options, txn_db_options, dbname, &db);
} else {
s = OpenWithStackableDB();
}
assert(s.ok());
}
~TransactionTest() {
delete db;
DestroyDB(dbname, options);
delete env;
}
Status ReOpenNoDelete() {
delete db;
db = nullptr;
env->AssertNoOpenFile();
env->DropUnsyncedFileData();
env->ResetState();
Status s;
if (std::get<0>(GetParam()) == false) {
s = TransactionDB::Open(options, txn_db_options, dbname, &db);
} else {
s = OpenWithStackableDB();
}
return s;
}
Status ReOpen() {
delete db;
DestroyDB(dbname, options);
Status s;
if (std::get<0>(GetParam()) == false) {
s = TransactionDB::Open(options, txn_db_options, dbname, &db);
} else {
s = OpenWithStackableDB();
}
return s;
}
Status OpenWithStackableDB() {
std::vector<size_t> compaction_enabled_cf_indices;
std::vector<ColumnFamilyDescriptor> column_families{ColumnFamilyDescriptor(
kDefaultColumnFamilyName, ColumnFamilyOptions(options))};
TransactionDB::PrepareWrap(&options, &column_families,
&compaction_enabled_cf_indices);
std::vector<ColumnFamilyHandle*> handles;
DB* root_db;
Options options_copy(options);
Status s =
DB::Open(options_copy, dbname, column_families, &handles, &root_db);
if (s.ok()) {
assert(handles.size() == 1);
s = TransactionDB::WrapStackableDB(
new StackableDB(root_db), txn_db_options,
compaction_enabled_cf_indices, handles, &db);
delete handles[0];
}
return s;
}
};
class MySQLStyleTransactionTest : public TransactionTest {};
class WritePreparedTransactionTest : public TransactionTest {};
static const TxnDBWritePolicy wc = WRITE_COMMITTED;
static const TxnDBWritePolicy wp = WRITE_PREPARED;
// TODO(myabandeh): Instantiate the tests with other write policies
INSTANTIATE_TEST_CASE_P(DBAsBaseDB, TransactionTest,
::testing::Values(std::make_tuple(false, false, wc)));
::testing::Values(std::make_tuple(false, false,
WRITE_COMMITTED)));
INSTANTIATE_TEST_CASE_P(StackableDBAsBaseDB, TransactionTest,
::testing::Values(std::make_tuple(true, false, wc)));
INSTANTIATE_TEST_CASE_P(MySQLStyleTransactionTest, MySQLStyleTransactionTest,
::testing::Values(std::make_tuple(false, false, wc),
std::make_tuple(false, true, wc),
std::make_tuple(true, false, wc),
std::make_tuple(true, true, wc)));
INSTANTIATE_TEST_CASE_P(WritePreparedTransactionTest,
WritePreparedTransactionTest,
::testing::Values(std::make_tuple(false, true, wp)));
::testing::Values(std::make_tuple(true, false,
WRITE_COMMITTED)));
INSTANTIATE_TEST_CASE_P(
MySQLStyleTransactionTest, MySQLStyleTransactionTest,
::testing::Values(std::make_tuple(false, false, WRITE_COMMITTED),
std::make_tuple(false, true, WRITE_COMMITTED),
std::make_tuple(true, false, WRITE_COMMITTED),
std::make_tuple(true, true, WRITE_COMMITTED)));
TEST_P(TransactionTest, DoubleEmptyWrite) {
WriteOptions write_options;
@ -4733,138 +4640,6 @@ TEST_P(TransactionTest, MemoryLimitTest) {
delete txn;
}
// Test WritePreparedTxnDB's IsInSnapshot against different ordering of
// snapshot, max_committed_seq_, prepared, and commit entries.
TEST_P(WritePreparedTransactionTest, IsInSnapshotTest) {
WriteOptions wo;
// Use small commit cache to trigger lots of eviction and fast advance of
// max_evicted_seq_
// will take effect after ReOpen
WritePreparedTxnDB::DEF_COMMIT_CACHE_SIZE = 8;
// Same for snapshot cache size
WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE = 5;
// Take some preliminary snapshots first. This is to stress the data structure
// that holds the old snapshots as it will be designed to be efficient when
// only a few snapshots are below the max_evicted_seq_.
for (int max_snapshots = 1; max_snapshots < 20; max_snapshots++) {
// Leave some gap between the preliminary snapshots and the final snapshot
// that we check. This should test for also different overlapping scnearios
// between the last snapshot and the commits.
for (int max_gap = 1; max_gap < 10; max_gap++) {
// Since we do not actually write to db, we mock the seq as it would be
// increaased by the db. The only exception is that we need db seq to
// advance for our snapshots. for which we apply a dummy put each time we
// increase our mock of seq.
uint64_t seq = 0;
// At each step we prepare a txn and then we commit it in the next txn.
// This emulates the consecuitive transactions that write to the same key
uint64_t cur_txn = 0;
// Number of snapshots taken so far
int num_snapshots = 0;
std::vector<const Snapshot*> to_be_released;
// Number of gaps applied so far
int gap_cnt = 0;
// The final snapshot that we will inspect
uint64_t snapshot = 0;
bool found_committed = false;
// To stress the data structure that maintain prepared txns, at each cycle
// we add a new prepare txn. These do not mean to be committed for
// snapshot inspection.
std::set<uint64_t> prepared;
// 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;
ReOpen(); // to restart the db
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
assert(wp_db);
assert(wp_db->db_impl_);
// We continue until max advances a bit beyond the snapshot.
while (!snapshot || wp_db->max_evicted_seq_ < snapshot + 100) {
// do prepare for a transaction
wp_db->db_impl_->Put(wo, "key", "value"); // dummy put to inc db seq
seq++;
ASSERT_EQ(wp_db->db_impl_->GetLatestSequenceNumber(), seq);
wp_db->AddPrepared(seq);
prepared.insert(seq);
// If cur_txn is not started, do prepare for it.
if (!cur_txn) {
wp_db->db_impl_->Put(wo, "key", "value"); // dummy put to inc db seq
seq++;
ASSERT_EQ(wp_db->db_impl_->GetLatestSequenceNumber(), seq);
cur_txn = seq;
wp_db->AddPrepared(cur_txn);
} else { // else commit it
wp_db->db_impl_->Put(wo, "key", "value"); // dummy put to inc db seq
seq++;
ASSERT_EQ(wp_db->db_impl_->GetLatestSequenceNumber(), seq);
wp_db->AddCommitted(cur_txn, seq);
if (!snapshot) {
committed_before.insert(cur_txn);
}
cur_txn = 0;
}
if (num_snapshots < max_snapshots - 1) {
// Take preliminary snapshots
auto tmp_snapshot = db->GetSnapshot();
to_be_released.push_back(tmp_snapshot);
num_snapshots++;
} else if (gap_cnt < max_gap) {
// Wait for some gap before taking the final snapshot
gap_cnt++;
} else if (!snapshot) {
// Take the final snapshot if it is not already taken
auto tmp_snapshot = db->GetSnapshot();
to_be_released.push_back(tmp_snapshot);
snapshot = tmp_snapshot->GetSequenceNumber();
// We increase the db seq artificailly by a dummy Put. Check that this
// technique is effective and db seq is that same as ours.
ASSERT_EQ(snapshot, seq);
num_snapshots++;
}
// If the snapshot is taken, verify seq numbers visible to it. We redo
// 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++) {
bool was_committed =
(committed_before.find(s) != committed_before.end());
bool is_in_snapshot = wp_db->IsInSnapshot(s, snapshot);
if (was_committed != is_in_snapshot) {
printf("max_snapshots %d max_gap %d seq %" PRIu64 " max %" PRIu64
" snapshot %" PRIu64
" gap_cnt %d num_snapshots %d s %" PRIu64 "\n",
max_snapshots, max_gap, seq,
wp_db->max_evicted_seq_.load(), snapshot, gap_cnt,
num_snapshots, s);
}
ASSERT_EQ(was_committed, is_in_snapshot);
found_committed = found_committed || is_in_snapshot;
}
}
}
// Safety check to make sure the test actually ran
ASSERT_TRUE(found_committed);
// As an extra check, check if prepared set will be properly empty after
// they are committed.
if (cur_txn) {
wp_db->AddCommitted(cur_txn, seq);
}
for (auto p : prepared) {
wp_db->AddCommitted(p, seq);
}
ASSERT_TRUE(wp_db->delayed_prepared_.empty());
ASSERT_TRUE(wp_db->prepared_txns_.empty());
for (auto s : to_be_released) {
db->ReleaseSnapshot(s);
}
}
}
}
} // namespace rocksdb
int main(int argc, char** argv) {

131
utilities/transactions/transaction_test.h Normal file
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@ -0,0 +1,131 @@
// 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).
#pragma once
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <algorithm>
#include <functional>
#include <string>
#include <thread>
#include "db/db_impl.h"
#include "rocksdb/db.h"
#include "rocksdb/options.h"
#include "rocksdb/utilities/transaction.h"
#include "rocksdb/utilities/transaction_db.h"
#include "table/mock_table.h"
#include "util/fault_injection_test_env.h"
#include "util/random.h"
#include "util/string_util.h"
#include "util/sync_point.h"
#include "util/testharness.h"
#include "util/testutil.h"
#include "util/transaction_test_util.h"
#include "utilities/merge_operators.h"
#include "utilities/merge_operators/string_append/stringappend.h"
#include "utilities/transactions/pessimistic_transaction_db.h"
#include "port/port.h"
namespace rocksdb {
class TransactionTest : public ::testing::TestWithParam<
std::tuple<bool, bool, TxnDBWritePolicy>> {
public:
TransactionDB* db;
FaultInjectionTestEnv* env;
std::string dbname;
Options options;
TransactionDBOptions txn_db_options;
TransactionTest() {
options.create_if_missing = true;
options.max_write_buffer_number = 2;
options.write_buffer_size = 4 * 1024;
options.level0_file_num_compaction_trigger = 2;
options.merge_operator = MergeOperators::CreateFromStringId("stringappend");
env = new FaultInjectionTestEnv(Env::Default());
options.env = env;
options.concurrent_prepare = std::get<1>(GetParam());
dbname = test::TmpDir() + "/transaction_testdb";
DestroyDB(dbname, options);
txn_db_options.transaction_lock_timeout = 0;
txn_db_options.default_lock_timeout = 0;
txn_db_options.write_policy = std::get<2>(GetParam());
Status s;
if (std::get<0>(GetParam()) == false) {
s = TransactionDB::Open(options, txn_db_options, dbname, &db);
} else {
s = OpenWithStackableDB();
}
assert(s.ok());
}
~TransactionTest() {
delete db;
DestroyDB(dbname, options);
delete env;
}
Status ReOpenNoDelete() {
delete db;
db = nullptr;
env->AssertNoOpenFile();
env->DropUnsyncedFileData();
env->ResetState();
Status s;
if (std::get<0>(GetParam()) == false) {
s = TransactionDB::Open(options, txn_db_options, dbname, &db);
} else {
s = OpenWithStackableDB();
}
return s;
}
Status ReOpen() {
delete db;
DestroyDB(dbname, options);
Status s;
if (std::get<0>(GetParam()) == false) {
s = TransactionDB::Open(options, txn_db_options, dbname, &db);
} else {
s = OpenWithStackableDB();
}
return s;
}
Status OpenWithStackableDB() {
std::vector<size_t> compaction_enabled_cf_indices;
std::vector<ColumnFamilyDescriptor> column_families{ColumnFamilyDescriptor(
kDefaultColumnFamilyName, ColumnFamilyOptions(options))};
TransactionDB::PrepareWrap(&options, &column_families,
&compaction_enabled_cf_indices);
std::vector<ColumnFamilyHandle*> handles;
DB* root_db;
Options options_copy(options);
Status s =
DB::Open(options_copy, dbname, column_families, &handles, &root_db);
if (s.ok()) {
assert(handles.size() == 1);
s = TransactionDB::WrapStackableDB(
new StackableDB(root_db), txn_db_options,
compaction_enabled_cf_indices, handles, &db);
delete handles[0];
}
return s;
}
};
class MySQLStyleTransactionTest : public TransactionTest {};
} // namespace rocksdb

569
utilities/transactions/write_prepared_transaction_test.cc Normal file
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@ -0,0 +1,569 @@
// 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).
#ifndef ROCKSDB_LITE
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include "utilities/transactions/transaction_test.h"
#include <inttypes.h>
#include <algorithm>
#include <functional>
#include <string>
#include <thread>
#include "db/db_impl.h"
#include "rocksdb/db.h"
#include "rocksdb/options.h"
#include "rocksdb/utilities/transaction.h"
#include "rocksdb/utilities/transaction_db.h"
#include "table/mock_table.h"
#include "util/fault_injection_test_env.h"
#include "util/random.h"
#include "util/string_util.h"
#include "util/sync_point.h"
#include "util/testharness.h"
#include "util/testutil.h"
#include "util/transaction_test_util.h"
#include "utilities/merge_operators.h"
#include "utilities/merge_operators/string_append/stringappend.h"
#include "utilities/transactions/pessimistic_transaction_db.h"
#include "port/port.h"
using std::string;
namespace rocksdb {
using CommitEntry = PessimisticTransactionDB::CommitEntry;
TEST(PreparedHeap, BasicsTest) {
WritePreparedTxnDB::PreparedHeap heap;
heap.push(14l);
// Test with one element
ASSERT_EQ(14l, heap.top());
heap.push(24l);
heap.push(34l);
// Test that old min is still on top
ASSERT_EQ(14l, heap.top());
heap.push(13l);
// Test that the new min will be on top
ASSERT_EQ(13l, heap.top());
// Test that it is persistent
ASSERT_EQ(13l, heap.top());
heap.push(44l);
heap.push(54l);
heap.push(64l);
heap.push(74l);
heap.push(84l);
// Test that old min is still on top
ASSERT_EQ(13l, heap.top());
heap.erase(24l);
// Test that old min is still on top
ASSERT_EQ(13l, heap.top());
heap.erase(14l);
// Test that old min is still on top
ASSERT_EQ(13l, heap.top());
heap.erase(13l);
// Test that the new comes to the top after multiple erase
ASSERT_EQ(34l, heap.top());
heap.erase(34l);
// Test that the new comes to the top after single erase
ASSERT_EQ(44l, heap.top());
heap.erase(54l);
ASSERT_EQ(44l, heap.top());
heap.pop(); // pop 44l
// Test that the erased items are ignored after pop
ASSERT_EQ(64l, heap.top());
heap.erase(44l);
// Test that erasing an already popped item would work
ASSERT_EQ(64l, heap.top());
heap.erase(84l);
ASSERT_EQ(64l, heap.top());
heap.push(85l);
heap.push(86l);
heap.push(87l);
heap.push(88l);
heap.push(89l);
heap.erase(87l);
heap.erase(85l);
heap.erase(89l);
heap.erase(86l);
heap.erase(88l);
// Test top remians the same after a ranodm order of many erases
ASSERT_EQ(64l, heap.top());
heap.pop();
// Test that pop works with a series of random pending erases
ASSERT_EQ(74l, heap.top());
ASSERT_FALSE(heap.empty());
heap.pop();
// Test that empty works
ASSERT_TRUE(heap.empty());
}
class WritePreparedTransactionTest : public TransactionTest {
protected:
// If expect_update is set, check if it actually updated old_commit_map_. If
// it did not and yet suggested not to check the next snapshot, do the
// opposite to check if it was not a bad suggstion.
void MaybeUpdateOldCommitMapTestWithNext(uint64_t prepare, uint64_t commit,
uint64_t snapshot,
uint64_t next_snapshot,
bool expect_update) {
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
// reset old_commit_map_empty_ so that its value indicate whether
// old_commit_map_ was updated
wp_db->old_commit_map_empty_ = true;
bool check_next = wp_db->MaybeUpdateOldCommitMap(prepare, commit, snapshot,
snapshot < next_snapshot);
if (expect_update == wp_db->old_commit_map_empty_) {
printf("prepare: %" PRIu64 " commit: %" PRIu64 " snapshot: %" PRIu64
" next: %" PRIu64 "\n",
prepare, commit, snapshot, next_snapshot);
}
EXPECT_EQ(!expect_update, wp_db->old_commit_map_empty_);
if (!check_next && wp_db->old_commit_map_empty_) {
// do the oppotisite to make sure it was not a bad suggestion
const bool dont_care_bool = true;
wp_db->MaybeUpdateOldCommitMap(prepare, commit, next_snapshot,
dont_care_bool);
if (!wp_db->old_commit_map_empty_) {
printf("prepare: %" PRIu64 " commit: %" PRIu64 " snapshot: %" PRIu64
" next: %" PRIu64 "\n",
prepare, commit, snapshot, next_snapshot);
}
EXPECT_TRUE(wp_db->old_commit_map_empty_);
}
}
// Test that a CheckAgainstSnapshots thread reading old_snapshots will not
// miss a snapshot because of a concurrent update by UpdateSnapshots that is
// writing new_snapshots. Both threads are broken at two points. The sync
// points to enforce them are specified by a1, a2, b1, and b2. CommitEntry
// entry is expected to be vital for one of the snapshots that is common
// between the old and new list of snapshots.
void SnapshotConcurrentAccessTestInternal(
WritePreparedTxnDB* wp_db,
const std::vector<SequenceNumber>& old_snapshots,
const std::vector<SequenceNumber>& new_snapshots, CommitEntry& entry,
SequenceNumber& version, size_t a1, size_t a2, size_t b1, size_t b2) {
// First reset the snapshot list
const std::vector<SequenceNumber> empty_snapshots;
wp_db->old_commit_map_empty_ = true;
wp_db->UpdateSnapshots(empty_snapshots, ++version);
// Then initialize it with the old_snapshots
wp_db->UpdateSnapshots(old_snapshots, ++version);
// Starting from the first thread, cut each thread at two points
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"WritePreparedTxnDB::CheckAgainstSnapshots:p:" + std::to_string(a1),
"WritePreparedTxnDB::UpdateSnapshots:s:start"},
{"WritePreparedTxnDB::UpdateSnapshots:p:" + std::to_string(b1),
"WritePreparedTxnDB::CheckAgainstSnapshots:s:" + std::to_string(a1)},
{"WritePreparedTxnDB::CheckAgainstSnapshots:p:" + std::to_string(a2),
"WritePreparedTxnDB::UpdateSnapshots:s:" + std::to_string(b1)},
{"WritePreparedTxnDB::UpdateSnapshots:p:" + std::to_string(b2),
"WritePreparedTxnDB::CheckAgainstSnapshots:s:" + std::to_string(a2)},
{"WritePreparedTxnDB::CheckAgainstSnapshots:p:end",
"WritePreparedTxnDB::UpdateSnapshots:s:" + std::to_string(b2)},
});
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
{
ASSERT_TRUE(wp_db->old_commit_map_empty_);
rocksdb::port::Thread t1(
[&]() { wp_db->UpdateSnapshots(new_snapshots, version); });
rocksdb::port::Thread t2([&]() { wp_db->CheckAgainstSnapshots(entry); });
t1.join();
t2.join();
ASSERT_FALSE(wp_db->old_commit_map_empty_);
}
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
wp_db->old_commit_map_empty_ = true;
wp_db->UpdateSnapshots(empty_snapshots, ++version);
wp_db->UpdateSnapshots(old_snapshots, ++version);
// Starting from the second thread, cut each thread at two points
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"WritePreparedTxnDB::UpdateSnapshots:p:" + std::to_string(a1),
"WritePreparedTxnDB::CheckAgainstSnapshots:s:start"},
{"WritePreparedTxnDB::CheckAgainstSnapshots:p:" + std::to_string(b1),
"WritePreparedTxnDB::UpdateSnapshots:s:" + std::to_string(a1)},
{"WritePreparedTxnDB::UpdateSnapshots:p:" + std::to_string(a2),
"WritePreparedTxnDB::CheckAgainstSnapshots:s:" + std::to_string(b1)},
{"WritePreparedTxnDB::CheckAgainstSnapshots:p:" + std::to_string(b2),
"WritePreparedTxnDB::UpdateSnapshots:s:" + std::to_string(a2)},
{"WritePreparedTxnDB::UpdateSnapshots:p:end",
"WritePreparedTxnDB::CheckAgainstSnapshots:s:" + std::to_string(b2)},
});
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
{
ASSERT_TRUE(wp_db->old_commit_map_empty_);
rocksdb::port::Thread t1(
[&]() { wp_db->UpdateSnapshots(new_snapshots, version); });
rocksdb::port::Thread t2([&]() { wp_db->CheckAgainstSnapshots(entry); });
t1.join();
t2.join();
ASSERT_FALSE(wp_db->old_commit_map_empty_);
}
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
};
INSTANTIATE_TEST_CASE_P(WritePreparedTransactionTest,
WritePreparedTransactionTest,
::testing::Values(std::make_tuple(false, true,
WRITE_PREPARED)));
TEST_P(WritePreparedTransactionTest, CommitMapTest) {
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
assert(wp_db);
assert(wp_db->db_impl_);
size_t size = wp_db->COMMIT_CACHE_SIZE;
CommitEntry c = {5, 12}, e;
bool evicted = wp_db->AddCommitEntry(c.prep_seq % size, c, &e);
ASSERT_FALSE(evicted);
// Should be able to read the same value
bool found = wp_db->GetCommitEntry(c.prep_seq % size, &e);
ASSERT_TRUE(found);
ASSERT_EQ(c, e);
// Should be able to distinguish between overlapping entries
found = wp_db->GetCommitEntry((c.prep_seq + size) % size, &e);
ASSERT_TRUE(found);
ASSERT_NE(c.prep_seq + size, e.prep_seq);
// Should be able to detect non-existent entry
found = wp_db->GetCommitEntry((c.prep_seq + 1) % size, &e);
ASSERT_EQ(e.commit_seq, 0);
ASSERT_FALSE(found);
// Reject an invalid exchange
CommitEntry e2 = {c.prep_seq + size, c.commit_seq};
bool exchanged = wp_db->ExchangeCommitEntry(e2.prep_seq % size, e2, e);
ASSERT_FALSE(exchanged);
// check whether it did actually reject that
found = wp_db->GetCommitEntry(e2.prep_seq % size, &e);
ASSERT_TRUE(found);
ASSERT_EQ(c, e);
// Accept a valid exchange
CommitEntry e3 = {c.prep_seq + size, c.commit_seq + size + 1};
exchanged = wp_db->ExchangeCommitEntry(c.prep_seq % size, c, e3);
ASSERT_TRUE(exchanged);
// check whether it did actually accepted that
found = wp_db->GetCommitEntry(c.prep_seq % size, &e);
ASSERT_TRUE(found);
ASSERT_EQ(e3, e);
// Rewrite an entry
CommitEntry e4 = {e3.prep_seq + size, e3.commit_seq + size + 1};
evicted = wp_db->AddCommitEntry(e4.prep_seq % size, e4, &e);
ASSERT_TRUE(evicted);
ASSERT_EQ(e3, e);
found = wp_db->GetCommitEntry(e4.prep_seq % size, &e);
ASSERT_TRUE(found);
ASSERT_EQ(e4, e);
}
TEST_P(WritePreparedTransactionTest, MaybeUpdateOldCommitMap) {
// If prepare <= snapshot < commit we should keep the entry around since its
// nonexistence could be interpreted as committed in the snapshot while it is
// not true. We keep such entries around by adding them to the
// old_commit_map_.
uint64_t p /*prepare*/, c /*commit*/, s /*snapshot*/, ns /*next_snapshot*/;
p = 10l, c = 15l, s = 20l, ns = 21l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
// If we do not expect the old commit map to be updated, try also with a next
// snapshot that is expected to update the old commit map. This would test
// that MaybeUpdateOldCommitMap would not prevent us from checking the next
// snapshot that must be checked.
p = 10l, c = 15l, s = 20l, ns = 11l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
p = 10l, c = 20l, s = 20l, ns = 19l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
p = 10l, c = 20l, s = 20l, ns = 21l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
p = 20l, c = 20l, s = 20l, ns = 21l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
p = 20l, c = 20l, s = 20l, ns = 19l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
p = 10l, c = 25l, s = 20l, ns = 21l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, true);
p = 20l, c = 25l, s = 20l, ns = 21l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, true);
p = 21l, c = 25l, s = 20l, ns = 22l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
p = 21l, c = 25l, s = 20l, ns = 19l;
MaybeUpdateOldCommitMapTestWithNext(p, c, s, ns, false);
}
TEST_P(WritePreparedTransactionTest, CheckAgainstSnapshotsTest) {
std::vector<SequenceNumber> snapshots = {100l, 200l, 300l, 400l,
500l, 600l, 700l};
// will take effect after ReOpen
WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE = snapshots.size() / 2;
ReOpen(); // to restart the db
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
assert(wp_db);
assert(wp_db->db_impl_);
SequenceNumber version = 1000l;
ASSERT_EQ(0, wp_db->snapshots_total_);
wp_db->UpdateSnapshots(snapshots, version);
ASSERT_EQ(snapshots.size(), wp_db->snapshots_total_);
// seq numbers are chosen so that we have two of them between each two
// snapshots. If the diff of two consecuitive seq is more than 5, there is a
// snapshot between them.
std::vector<SequenceNumber> seqs = {50l, 55l, 150l, 155l, 250l, 255l,
350l, 355l, 450l, 455l, 550l, 555l,
650l, 655l, 750l, 755l};
assert(seqs.size() > 1);
for (size_t i = 0; i < seqs.size() - 1; i++) {
wp_db->old_commit_map_empty_ = true; // reset
CommitEntry commit_entry = {seqs[i], seqs[i + 1]};
wp_db->CheckAgainstSnapshots(commit_entry);
// Expect update if there is snapshot in between the prepare and commit
bool expect_update = commit_entry.commit_seq - commit_entry.prep_seq > 5 &&
commit_entry.commit_seq >= snapshots.front() &&
commit_entry.prep_seq <= snapshots.back();
ASSERT_EQ(expect_update, !wp_db->old_commit_map_empty_);
}
}
// Return true if the ith bit is set in combination represented by comb
bool IsInCombination(size_t i, size_t comb) { return comb & (1 << i); }
// Test that CheckAgainstSnapshots will not miss a live snapshot if it is run in
// parallel with UpdateSnapshots.
TEST_P(WritePreparedTransactionTest, SnapshotConcurrentAccessTest) {
// We have a sync point in the method under test after checking each snapshot.
// If you increase the max number of snapshots in this test, more sync points
// in the methods must also be added.
const std::vector<SequenceNumber> snapshots = {10l, 20l, 30l, 40l, 50l,
60l, 70l, 80l, 90l, 100l};
SequenceNumber version = 1000l;
// Choose the cache size so that the new snapshot list could replace all the
// existing items in the cache and also have some overflow Will take effect
// after ReOpen
WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE = (snapshots.size() - 2) / 2;
ReOpen(); // to restart the db
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
assert(wp_db);
assert(wp_db->db_impl_);
// Add up to 2 items that do not fit into the cache
for (size_t old_size = 1;
old_size <= WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE + 2;
old_size++) {
const std::vector<SequenceNumber> old_snapshots(
snapshots.begin(), snapshots.begin() + old_size);
// Each member of old snapshot might or might not appear in the new list. We
// create a common_snapshots for each combination.
size_t new_comb_cnt = static_cast<size_t>(1 << old_size);
for (size_t new_comb = 0; new_comb < new_comb_cnt; new_comb++) {
std::vector<SequenceNumber> common_snapshots;
for (size_t i = 0; i < old_snapshots.size(); i++) {
if (IsInCombination(i, new_comb)) {
common_snapshots.push_back(old_snapshots[i]);
}
}
// And add some new snapshots to the common list
for (size_t added_snapshots = 0;
added_snapshots <= snapshots.size() - old_snapshots.size();
added_snapshots++) {
std::vector<SequenceNumber> new_snapshots = common_snapshots;
for (size_t i = 0; i < added_snapshots; i++) {
new_snapshots.push_back(snapshots[old_snapshots.size() + i]);
}
for (auto it = common_snapshots.begin(); it != common_snapshots.end();
it++) {
auto snapshot = *it;
// Create a commit entry that is around the snapshot and thus should
// be not be discarded
CommitEntry entry = {static_cast<uint64_t>(snapshot - 1),
snapshot + 1};
// The critical part is when iterating the snapshot cache. Afterwards,
// we are operating under the lock
size_t a_range =
std::min(old_snapshots.size(),
WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE) +
1;
size_t b_range =
std::min(new_snapshots.size(),
WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE) +
1;
// Break each thread at two points
for (size_t a1 = 1; a1 <= a_range; a1++) {
for (size_t a2 = a1 + 1; a2 <= a_range; a2++) {
for (size_t b1 = 1; b1 <= b_range; b1++) {
for (size_t b2 = b1 + 1; b2 <= b_range; b2++) {
SnapshotConcurrentAccessTestInternal(wp_db, old_snapshots,
new_snapshots, entry,
version, a1, a2, b1, b2);
}
}
}
}
}
}
}
}
}
// Test WritePreparedTxnDB's IsInSnapshot against different ordering of
// snapshot, max_committed_seq_, prepared, and commit entries.
TEST_P(WritePreparedTransactionTest, IsInSnapshotTest) {
WriteOptions wo;
// Use small commit cache to trigger lots of eviction and fast advance of
// max_evicted_seq_
// will take effect after ReOpen
WritePreparedTxnDB::DEF_COMMIT_CACHE_SIZE = 8;
// Same for snapshot cache size
WritePreparedTxnDB::DEF_SNAPSHOT_CACHE_SIZE = 5;
// Take some preliminary snapshots first. This is to stress the data structure
// that holds the old snapshots as it will be designed to be efficient when
// only a few snapshots are below the max_evicted_seq_.
for (int max_snapshots = 1; max_snapshots < 20; max_snapshots++) {
// Leave some gap between the preliminary snapshots and the final snapshot
// that we check. This should test for also different overlapping scnearios
// between the last snapshot and the commits.
for (int max_gap = 1; max_gap < 10; max_gap++) {
// Since we do not actually write to db, we mock the seq as it would be
// increaased by the db. The only exception is that we need db seq to
// advance for our snapshots. for which we apply a dummy put each time we
// increase our mock of seq.
uint64_t seq = 0;
// At each step we prepare a txn and then we commit it in the next txn.
// This emulates the consecuitive transactions that write to the same key
uint64_t cur_txn = 0;
// Number of snapshots taken so far
int num_snapshots = 0;
std::vector<const Snapshot*> to_be_released;
// Number of gaps applied so far
int gap_cnt = 0;
// The final snapshot that we will inspect
uint64_t snapshot = 0;
bool found_committed = false;
// To stress the data structure that maintain prepared txns, at each cycle
// we add a new prepare txn. These do not mean to be committed for
// snapshot inspection.
std::set<uint64_t> prepared;
// 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;
ReOpen(); // to restart the db
WritePreparedTxnDB* wp_db = dynamic_cast<WritePreparedTxnDB*>(db);
assert(wp_db);
assert(wp_db->db_impl_);
// We continue until max advances a bit beyond the snapshot.
while (!snapshot || wp_db->max_evicted_seq_ < snapshot + 100) {
// do prepare for a transaction
wp_db->db_impl_->Put(wo, "key", "value"); // dummy put to inc db seq
seq++;
ASSERT_EQ(wp_db->db_impl_->GetLatestSequenceNumber(), seq);
wp_db->AddPrepared(seq);
prepared.insert(seq);
// If cur_txn is not started, do prepare for it.
if (!cur_txn) {
wp_db->db_impl_->Put(wo, "key", "value"); // dummy put to inc db seq
seq++;
ASSERT_EQ(wp_db->db_impl_->GetLatestSequenceNumber(), seq);
cur_txn = seq;
wp_db->AddPrepared(cur_txn);
} else { // else commit it
wp_db->db_impl_->Put(wo, "key", "value"); // dummy put to inc db seq
seq++;
ASSERT_EQ(wp_db->db_impl_->GetLatestSequenceNumber(), seq);
wp_db->AddCommitted(cur_txn, seq);
if (!snapshot) {
committed_before.insert(cur_txn);
}
cur_txn = 0;
}
if (num_snapshots < max_snapshots - 1) {
// Take preliminary snapshots
auto tmp_snapshot = db->GetSnapshot();
to_be_released.push_back(tmp_snapshot);
num_snapshots++;
} else if (gap_cnt < max_gap) {
// Wait for some gap before taking the final snapshot
gap_cnt++;
} else if (!snapshot) {
// Take the final snapshot if it is not already taken
auto tmp_snapshot = db->GetSnapshot();
to_be_released.push_back(tmp_snapshot);
snapshot = tmp_snapshot->GetSequenceNumber();
// We increase the db seq artificailly by a dummy Put. Check that this
// technique is effective and db seq is that same as ours.
ASSERT_EQ(snapshot, seq);
num_snapshots++;
}
// If the snapshot is taken, verify seq numbers visible to it. We redo
// 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++) {
bool was_committed =
(committed_before.find(s) != committed_before.end());
bool is_in_snapshot = wp_db->IsInSnapshot(s, snapshot);
if (was_committed != is_in_snapshot) {
printf("max_snapshots %d max_gap %d seq %" PRIu64 " max %" PRIu64
" snapshot %" PRIu64
" gap_cnt %d num_snapshots %d s %" PRIu64 "\n",
max_snapshots, max_gap, seq,
wp_db->max_evicted_seq_.load(), snapshot, gap_cnt,
num_snapshots, s);
}
ASSERT_EQ(was_committed, is_in_snapshot);
found_committed = found_committed || is_in_snapshot;
}
}
}
// Safety check to make sure the test actually ran
ASSERT_TRUE(found_committed);
// As an extra check, check if prepared set will be properly empty after
// they are committed.
if (cur_txn) {
wp_db->AddCommitted(cur_txn, seq);
}
for (auto p : prepared) {
wp_db->AddCommitted(p, seq);
}
ASSERT_TRUE(wp_db->delayed_prepared_.empty());
ASSERT_TRUE(wp_db->prepared_txns_.empty());
for (auto s : to_be_released) {
db->ReleaseSnapshot(s);
}
}
}
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
#else
#include <stdio.h>
int main(int argc, char** argv) {
fprintf(stderr,
"SKIPPED as Transactions are not supported in ROCKSDB_LITE\n");
return 0;
}
#endif // ROCKSDB_LITE