// 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 #include #include #include #include #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(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& old_snapshots, const std::vector& 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 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(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 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(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 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 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(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 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(1 << old_size); for (size_t new_comb = 0; new_comb < new_comb_cnt; new_comb++) { std::vector 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 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(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 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 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 committed_before; ReOpen(); // to restart the db WritePreparedTxnDB* wp_db = dynamic_cast(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 int main(int argc, char** argv) { fprintf(stderr, "SKIPPED as Transactions are not supported in ROCKSDB_LITE\n"); return 0; } #endif // ROCKSDB_LITE