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5d9a623e2c
rocksdb/db/db_range_del_test.cc
Siying Dong cf3a671733 Remove cuckoo hash memtable (#4953) 
Summary:
Cuckoo Hash is less useful than we initially expected. Remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4953

Differential Revision: D13979264

Pulled By: siying

fbshipit-source-id: 2a60afdaa989f045357398b43a1cc5d46f4492ed
2019-02-07 16:15:27 -08:00

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// Copyright (c) 2016-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "db/db_test_util.h"
#include "port/stack_trace.h"
#include "util/testutil.h"
#include "utilities/merge_operators.h"
namespace rocksdb {
class DBRangeDelTest : public DBTestBase {
public:
DBRangeDelTest() : DBTestBase("/db_range_del_test") {}
std::string GetNumericStr(int key) {
uint64_t uint64_key = static_cast<uint64_t>(key);
std::string str;
str.resize(8);
memcpy(&str[0], static_cast<void*>(&uint64_key), 8);
return str;
}
};
// PlainTableFactory and NumTableFilesAtLevel() are not supported in
// ROCKSDB_LITE
#ifndef ROCKSDB_LITE
TEST_F(DBRangeDelTest, NonBlockBasedTableNotSupported) {
// TODO: figure out why MmapReads trips the iterator pinning assertion in
// RangeDelAggregator. Ideally it would be supported; otherwise it should at
// least be explicitly unsupported.
for (auto config : {kPlainTableAllBytesPrefix, /* kWalDirAndMmapReads */}) {
option_config_ = config;
DestroyAndReopen(CurrentOptions());
ASSERT_TRUE(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
"dr1", "dr1")
.IsNotSupported());
}
}
TEST_F(DBRangeDelTest, FlushOutputHasOnlyRangeTombstones) {
do {
DestroyAndReopen(CurrentOptions());
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
"dr1", "dr2"));
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_EQ(1, NumTableFilesAtLevel(0));
} while (ChangeOptions(kRangeDelSkipConfigs));
}
TEST_F(DBRangeDelTest, CompactionOutputHasOnlyRangeTombstone) {
do {
Options opts = CurrentOptions();
opts.disable_auto_compactions = true;
opts.statistics = CreateDBStatistics();
DestroyAndReopen(opts);
// snapshot protects range tombstone from dropping due to becoming obsolete.
const Snapshot* snapshot = db_->GetSnapshot();
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z");
db_->Flush(FlushOptions());
ASSERT_EQ(1, NumTableFilesAtLevel(0));
ASSERT_EQ(0, NumTableFilesAtLevel(1));
dbfull()->TEST_CompactRange(0, nullptr, nullptr, nullptr,
true /* disallow_trivial_move */);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(1, NumTableFilesAtLevel(1));
ASSERT_EQ(0, TestGetTickerCount(opts, COMPACTION_RANGE_DEL_DROP_OBSOLETE));
db_->ReleaseSnapshot(snapshot);
// Skip cuckoo memtables, which do not support snapshots. Skip non-leveled
// compactions as the above assertions about the number of files in a level
// do not hold true.
} while (ChangeOptions(kRangeDelSkipConfigs | kSkipUniversalCompaction |
kSkipFIFOCompaction));
}
TEST_F(DBRangeDelTest, CompactionOutputFilesExactlyFilled) {
// regression test for exactly filled compaction output files. Previously
// another file would be generated containing all range deletions, which
// could invalidate the non-overlapping file boundary invariant.
const int kNumPerFile = 4, kNumFiles = 2, kFileBytes = 9 << 10;
Options options = CurrentOptions();
options.disable_auto_compactions = true;
options.level0_file_num_compaction_trigger = kNumFiles;
options.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
options.num_levels = 2;
options.target_file_size_base = kFileBytes;
BlockBasedTableOptions table_options;
table_options.block_size_deviation = 50; // each block holds two keys
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
Reopen(options);
// snapshot protects range tombstone from dropping due to becoming obsolete.
const Snapshot* snapshot = db_->GetSnapshot();
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), Key(0), Key(1));
Random rnd(301);
for (int i = 0; i < kNumFiles; ++i) {
std::vector<std::string> values;
// Write 12K (4 values, each 3K)
for (int j = 0; j < kNumPerFile; j++) {
values.push_back(RandomString(&rnd, 3 << 10));
ASSERT_OK(Put(Key(i * kNumPerFile + j), values[j]));
if (j == 0 && i > 0) {
dbfull()->TEST_WaitForFlushMemTable();
}
}
}
// put extra key to trigger final flush
ASSERT_OK(Put("", ""));
dbfull()->TEST_WaitForFlushMemTable();
ASSERT_EQ(kNumFiles, NumTableFilesAtLevel(0));
ASSERT_EQ(0, NumTableFilesAtLevel(1));
dbfull()->TEST_CompactRange(0, nullptr, nullptr, nullptr,
true /* disallow_trivial_move */);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(2, NumTableFilesAtLevel(1));
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, MaxCompactionBytesCutsOutputFiles) {
// Ensures range deletion spanning multiple compaction output files that are
// cut by max_compaction_bytes will have non-overlapping key-ranges.
// https://github.com/facebook/rocksdb/issues/1778
const int kNumFiles = 2, kNumPerFile = 1 << 8, kBytesPerVal = 1 << 12;
Options opts = CurrentOptions();
opts.comparator = test::Uint64Comparator();
opts.disable_auto_compactions = true;
opts.level0_file_num_compaction_trigger = kNumFiles;
opts.max_compaction_bytes = kNumPerFile * kBytesPerVal;
opts.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
// Want max_compaction_bytes to trigger the end of compaction output file, not
// target_file_size_base, so make the latter much bigger
opts.target_file_size_base = 100 * opts.max_compaction_bytes;
Reopen(opts);
// snapshot protects range tombstone from dropping due to becoming obsolete.
const Snapshot* snapshot = db_->GetSnapshot();
// It spans the whole key-range, thus will be included in all output files
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
GetNumericStr(0),
GetNumericStr(kNumFiles * kNumPerFile - 1)));
Random rnd(301);
for (int i = 0; i < kNumFiles; ++i) {
std::vector<std::string> values;
// Write 1MB (256 values, each 4K)
for (int j = 0; j < kNumPerFile; j++) {
values.push_back(RandomString(&rnd, kBytesPerVal));
ASSERT_OK(Put(GetNumericStr(kNumPerFile * i + j), values[j]));
}
// extra entry to trigger SpecialSkipListFactory's flush
ASSERT_OK(Put(GetNumericStr(kNumPerFile), ""));
dbfull()->TEST_WaitForFlushMemTable();
ASSERT_EQ(i + 1, NumTableFilesAtLevel(0));
}
dbfull()->TEST_CompactRange(0, nullptr, nullptr, nullptr,
true /* disallow_trivial_move */);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_GE(NumTableFilesAtLevel(1), 2);
std::vector<std::vector<FileMetaData>> files;
dbfull()->TEST_GetFilesMetaData(db_->DefaultColumnFamily(), &files);
for (size_t i = 0; i < files[1].size() - 1; ++i) {
ASSERT_TRUE(InternalKeyComparator(opts.comparator)
.Compare(files[1][i].largest, files[1][i + 1].smallest) <
0);
}
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, SentinelsOmittedFromOutputFile) {
// Regression test for bug where sentinel range deletions (i.e., ones with
// sequence number of zero) were included in output files.
// snapshot protects range tombstone from dropping due to becoming obsolete.
const Snapshot* snapshot = db_->GetSnapshot();
// gaps between ranges creates sentinels in our internal representation
std::vector<std::pair<std::string, std::string>> range_dels = {{"a", "b"}, {"c", "d"}, {"e", "f"}};
for (const auto& range_del : range_dels) {
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
range_del.first, range_del.second));
}
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_EQ(1, NumTableFilesAtLevel(0));
std::vector<std::vector<FileMetaData>> files;
dbfull()->TEST_GetFilesMetaData(db_->DefaultColumnFamily(), &files);
ASSERT_GT(files[0][0].fd.smallest_seqno, 0);
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, FlushRangeDelsSameStartKey) {
db_->Put(WriteOptions(), "b1", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "c"));
db_->Put(WriteOptions(), "b2", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "b"));
// first iteration verifies query correctness in memtable, second verifies
// query correctness for a single SST file
for (int i = 0; i < 2; ++i) {
if (i > 0) {
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_EQ(1, NumTableFilesAtLevel(0));
}
std::string value;
ASSERT_TRUE(db_->Get(ReadOptions(), "b1", &value).IsNotFound());
ASSERT_OK(db_->Get(ReadOptions(), "b2", &value));
}
}
TEST_F(DBRangeDelTest, CompactRangeDelsSameStartKey) {
db_->Put(WriteOptions(), "unused", "val"); // prevents empty after compaction
db_->Put(WriteOptions(), "b1", "val");
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "c"));
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "b"));
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_EQ(3, NumTableFilesAtLevel(0));
for (int i = 0; i < 2; ++i) {
if (i > 0) {
dbfull()->TEST_CompactRange(0, nullptr, nullptr, nullptr,
true /* disallow_trivial_move */);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(1, NumTableFilesAtLevel(1));
}
std::string value;
ASSERT_TRUE(db_->Get(ReadOptions(), "b1", &value).IsNotFound());
}
}
#endif // ROCKSDB_LITE
TEST_F(DBRangeDelTest, FlushRemovesCoveredKeys) {
const int kNum = 300, kRangeBegin = 50, kRangeEnd = 250;
Options opts = CurrentOptions();
opts.comparator = test::Uint64Comparator();
Reopen(opts);
// Write a third before snapshot, a third between snapshot and tombstone, and
// a third after the tombstone. Keys older than snapshot or newer than the
// tombstone should be preserved.
const Snapshot* snapshot = nullptr;
for (int i = 0; i < kNum; ++i) {
if (i == kNum / 3) {
snapshot = db_->GetSnapshot();
} else if (i == 2 * kNum / 3) {
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
GetNumericStr(kRangeBegin), GetNumericStr(kRangeEnd));
}
db_->Put(WriteOptions(), GetNumericStr(i), "val");
}
db_->Flush(FlushOptions());
for (int i = 0; i < kNum; ++i) {
ReadOptions read_opts;
read_opts.ignore_range_deletions = true;
std::string value;
if (i < kRangeBegin || i > kRangeEnd || i < kNum / 3 || i >= 2 * kNum / 3) {
ASSERT_OK(db_->Get(read_opts, GetNumericStr(i), &value));
} else {
ASSERT_TRUE(db_->Get(read_opts, GetNumericStr(i), &value).IsNotFound());
}
}
db_->ReleaseSnapshot(snapshot);
}
// NumTableFilesAtLevel() is not supported in ROCKSDB_LITE
#ifndef ROCKSDB_LITE
TEST_F(DBRangeDelTest, CompactionRemovesCoveredKeys) {
const int kNumPerFile = 100, kNumFiles = 4;
Options opts = CurrentOptions();
opts.comparator = test::Uint64Comparator();
opts.disable_auto_compactions = true;
opts.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
opts.num_levels = 2;
opts.statistics = CreateDBStatistics();
Reopen(opts);
for (int i = 0; i < kNumFiles; ++i) {
if (i > 0) {
// range tombstone covers first half of the previous file
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
GetNumericStr((i - 1) * kNumPerFile),
GetNumericStr((i - 1) * kNumPerFile + kNumPerFile / 2));
}
// Make sure a given key appears in each file so compaction won't be able to
// use trivial move, which would happen if the ranges were non-overlapping.
// Also, we need an extra element since flush is only triggered when the
// number of keys is one greater than SpecialSkipListFactory's limit.
// We choose a key outside the key-range used by the test to avoid conflict.
db_->Put(WriteOptions(), GetNumericStr(kNumPerFile * kNumFiles), "val");
for (int j = 0; j < kNumPerFile; ++j) {
db_->Put(WriteOptions(), GetNumericStr(i * kNumPerFile + j), "val");
}
dbfull()->TEST_WaitForFlushMemTable();
ASSERT_EQ(i + 1, NumTableFilesAtLevel(0));
}
db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_GT(NumTableFilesAtLevel(1), 0);
ASSERT_EQ((kNumFiles - 1) * kNumPerFile / 2,
TestGetTickerCount(opts, COMPACTION_KEY_DROP_RANGE_DEL));
for (int i = 0; i < kNumFiles; ++i) {
for (int j = 0; j < kNumPerFile; ++j) {
ReadOptions read_opts;
read_opts.ignore_range_deletions = true;
std::string value;
if (i == kNumFiles - 1 || j >= kNumPerFile / 2) {
ASSERT_OK(
db_->Get(read_opts, GetNumericStr(i * kNumPerFile + j), &value));
} else {
ASSERT_TRUE(
db_->Get(read_opts, GetNumericStr(i * kNumPerFile + j), &value)
.IsNotFound());
}
}
}
}
TEST_F(DBRangeDelTest, ValidLevelSubcompactionBoundaries) {
const int kNumPerFile = 100, kNumFiles = 4, kFileBytes = 100 << 10;
Options options = CurrentOptions();
options.disable_auto_compactions = true;
options.level0_file_num_compaction_trigger = kNumFiles;
options.max_bytes_for_level_base = 2 * kFileBytes;
options.max_subcompactions = 4;
options.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
options.num_levels = 3;
options.target_file_size_base = kFileBytes;
options.target_file_size_multiplier = 1;
Reopen(options);
Random rnd(301);
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < kNumFiles; ++j) {
if (i > 0) {
// delete [95,105) in two files, [295,305) in next two
int mid = (j + (1 - j % 2)) * kNumPerFile;
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
Key(mid - 5), Key(mid + 5));
}
std::vector<std::string> values;
// Write 100KB (100 values, each 1K)
for (int k = 0; k < kNumPerFile; k++) {
values.push_back(RandomString(&rnd, 990));
ASSERT_OK(Put(Key(j * kNumPerFile + k), values[k]));
}
// put extra key to trigger flush
ASSERT_OK(Put("", ""));
dbfull()->TEST_WaitForFlushMemTable();
if (j < kNumFiles - 1) {
// background compaction may happen early for kNumFiles'th file
ASSERT_EQ(NumTableFilesAtLevel(0), j + 1);
}
if (j == options.level0_file_num_compaction_trigger - 1) {
// When i == 1, compaction will output some files to L1, at which point
// L1 is not bottommost so range deletions cannot be compacted away. The
// new L1 files must be generated with non-overlapping key ranges even
// though multiple subcompactions see the same ranges deleted, else an
// assertion will fail.
//
// Only enable auto-compactions when we're ready; otherwise, the
// oversized L0 (relative to base_level) causes the compaction to run
// earlier.
ASSERT_OK(db_->EnableAutoCompaction({db_->DefaultColumnFamily()}));
dbfull()->TEST_WaitForCompact();
ASSERT_OK(db_->SetOptions(db_->DefaultColumnFamily(),
{{"disable_auto_compactions", "true"}}));
ASSERT_EQ(NumTableFilesAtLevel(0), 0);
ASSERT_GT(NumTableFilesAtLevel(1), 0);
ASSERT_GT(NumTableFilesAtLevel(2), 0);
}
}
}
}
TEST_F(DBRangeDelTest, ValidUniversalSubcompactionBoundaries) {
const int kNumPerFile = 100, kFilesPerLevel = 4, kNumLevels = 4;
Options options = CurrentOptions();
options.compaction_options_universal.min_merge_width = kFilesPerLevel;
options.compaction_options_universal.max_merge_width = kFilesPerLevel;
options.compaction_options_universal.size_ratio = 10;
options.compaction_style = kCompactionStyleUniversal;
options.level0_file_num_compaction_trigger = kFilesPerLevel;
options.max_subcompactions = 4;
options.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
options.num_levels = kNumLevels;
options.target_file_size_base = kNumPerFile << 10;
options.target_file_size_multiplier = 1;
Reopen(options);
Random rnd(301);
for (int i = 0; i < kNumLevels - 1; ++i) {
for (int j = 0; j < kFilesPerLevel; ++j) {
if (i == kNumLevels - 2) {
// insert range deletions [95,105) in two files, [295,305) in next two
// to prepare L1 for later manual compaction.
int mid = (j + (1 - j % 2)) * kNumPerFile;
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
Key(mid - 5), Key(mid + 5));
}
std::vector<std::string> values;
// Write 100KB (100 values, each 1K)
for (int k = 0; k < kNumPerFile; k++) {
values.push_back(RandomString(&rnd, 990));
ASSERT_OK(Put(Key(j * kNumPerFile + k), values[k]));
}
// put extra key to trigger flush
ASSERT_OK(Put("", ""));
dbfull()->TEST_WaitForFlushMemTable();
if (j < kFilesPerLevel - 1) {
// background compaction may happen early for kFilesPerLevel'th file
ASSERT_EQ(NumTableFilesAtLevel(0), j + 1);
}
}
dbfull()->TEST_WaitForCompact();
ASSERT_EQ(NumTableFilesAtLevel(0), 0);
ASSERT_GT(NumTableFilesAtLevel(kNumLevels - 1 - i), kFilesPerLevel - 1);
}
// Now L1-L3 are full, when we compact L1->L2 we should see (1) subcompactions
// happen since input level > 0; (2) range deletions are not dropped since
// output level is not bottommost. If no file boundary assertion fails, that
// probably means universal compaction + subcompaction + range deletion are
// compatible.
ASSERT_OK(dbfull()->RunManualCompaction(
reinterpret_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())
->cfd(),
1 /* input_level */, 2 /* output_level */, 0 /* output_path_id */,
0 /* max_subcompactions */, nullptr /* begin */, nullptr /* end */,
true /* exclusive */, true /* disallow_trivial_move */));
}
#endif // ROCKSDB_LITE
TEST_F(DBRangeDelTest, CompactionRemovesCoveredMergeOperands) {
const int kNumPerFile = 3, kNumFiles = 3;
Options opts = CurrentOptions();
opts.disable_auto_compactions = true;
opts.memtable_factory.reset(new SpecialSkipListFactory(2 * kNumPerFile));
opts.merge_operator = MergeOperators::CreateUInt64AddOperator();
opts.num_levels = 2;
Reopen(opts);
// Iterates kNumFiles * kNumPerFile + 1 times since flushing the last file
// requires an extra entry.
for (int i = 0; i <= kNumFiles * kNumPerFile; ++i) {
if (i % kNumPerFile == 0 && i / kNumPerFile == kNumFiles - 1) {
// Delete merge operands from all but the last file
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "key",
"key_");
}
std::string val;
PutFixed64(&val, i);
db_->Merge(WriteOptions(), "key", val);
// we need to prevent trivial move using Puts so compaction will actually
// process the merge operands.
db_->Put(WriteOptions(), "prevent_trivial_move", "");
if (i > 0 && i % kNumPerFile == 0) {
dbfull()->TEST_WaitForFlushMemTable();
}
}
ReadOptions read_opts;
read_opts.ignore_range_deletions = true;
std::string expected, actual;
ASSERT_OK(db_->Get(read_opts, "key", &actual));
PutFixed64(&expected, 45); // 1+2+...+9
ASSERT_EQ(expected, actual);
db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
expected.clear();
ASSERT_OK(db_->Get(read_opts, "key", &actual));
uint64_t tmp;
Slice tmp2(actual);
GetFixed64(&tmp2, &tmp);
PutFixed64(&expected, 30); // 6+7+8+9 (earlier operands covered by tombstone)
ASSERT_EQ(expected, actual);
}
// NumTableFilesAtLevel() is not supported in ROCKSDB_LITE
#ifndef ROCKSDB_LITE
TEST_F(DBRangeDelTest, ObsoleteTombstoneCleanup) {
// During compaction to bottommost level, verify range tombstones older than
// the oldest snapshot are removed, while others are preserved.
Options opts = CurrentOptions();
opts.disable_auto_compactions = true;
opts.num_levels = 2;
opts.statistics = CreateDBStatistics();
Reopen(opts);
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "dr1",
"dr10"); // obsolete after compaction
db_->Put(WriteOptions(), "key", "val");
db_->Flush(FlushOptions());
const Snapshot* snapshot = db_->GetSnapshot();
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "dr2",
"dr20"); // protected by snapshot
db_->Put(WriteOptions(), "key", "val");
db_->Flush(FlushOptions());
ASSERT_EQ(2, NumTableFilesAtLevel(0));
ASSERT_EQ(0, NumTableFilesAtLevel(1));
db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(1, NumTableFilesAtLevel(1));
ASSERT_EQ(1, TestGetTickerCount(opts, COMPACTION_RANGE_DEL_DROP_OBSOLETE));
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, TableEvictedDuringScan) {
// The RangeDelAggregator holds pointers into range deletion blocks created by
// table readers. This test ensures the aggregator can still access those
// blocks even if it outlives the table readers that created them.
//
// DBIter always keeps readers open for L0 files. So, in order to test
// aggregator outliving reader, we need to have deletions in L1 files, which
// are opened/closed on-demand during the scan. This is accomplished by
// setting kNumRanges > level0_stop_writes_trigger, which prevents deletions
// from all lingering in L0 (there is at most one range deletion per L0 file).
//
// The first L1 file will contain a range deletion since its begin key is 0.
// SeekToFirst() references that table's reader and adds its range tombstone
// to the aggregator. Upon advancing beyond that table's key-range via Next(),
// the table reader will be unreferenced by the iterator. Since we manually
// call Evict() on all readers before the full scan, this unreference causes
// the reader's refcount to drop to zero and thus be destroyed.
//
// When it is destroyed, we do not remove its range deletions from the
// aggregator. So, subsequent calls to Next() must be able to use these
// deletions to decide whether a key is covered. This will work as long as
// the aggregator properly references the range deletion block.
const int kNum = 25, kRangeBegin = 0, kRangeEnd = 7, kNumRanges = 5;
Options opts = CurrentOptions();
opts.comparator = test::Uint64Comparator();
opts.level0_file_num_compaction_trigger = 4;
opts.level0_stop_writes_trigger = 4;
opts.memtable_factory.reset(new SpecialSkipListFactory(1));
opts.num_levels = 2;
BlockBasedTableOptions bbto;
bbto.cache_index_and_filter_blocks = true;
bbto.block_cache = NewLRUCache(8 << 20);
opts.table_factory.reset(NewBlockBasedTableFactory(bbto));
Reopen(opts);
// Hold a snapshot so range deletions can't become obsolete during compaction
// to bottommost level (i.e., L1).
const Snapshot* snapshot = db_->GetSnapshot();
for (int i = 0; i < kNum; ++i) {
db_->Put(WriteOptions(), GetNumericStr(i), "val");
if (i > 0) {
dbfull()->TEST_WaitForFlushMemTable();
}
if (i >= kNum / 2 && i < kNum / 2 + kNumRanges) {
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
GetNumericStr(kRangeBegin), GetNumericStr(kRangeEnd));
}
}
// Must be > 1 so the first L1 file can be closed before scan finishes
dbfull()->TEST_WaitForCompact();
ASSERT_GT(NumTableFilesAtLevel(1), 1);
std::vector<uint64_t> file_numbers = ListTableFiles(env_, dbname_);
ReadOptions read_opts;
auto* iter = db_->NewIterator(read_opts);
int expected = kRangeEnd;
iter->SeekToFirst();
for (auto file_number : file_numbers) {
// This puts table caches in the state of being externally referenced only
// so they are destroyed immediately upon iterator unreferencing.
TableCache::Evict(dbfull()->TEST_table_cache(), file_number);
}
for (; iter->Valid(); iter->Next()) {
ASSERT_EQ(GetNumericStr(expected), iter->key());
++expected;
// Keep clearing block cache's LRU so range deletion block can be freed as
// soon as its refcount drops to zero.
bbto.block_cache->EraseUnRefEntries();
}
ASSERT_EQ(kNum, expected);
delete iter;
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, GetCoveredKeyFromMutableMemtable) {
do {
DestroyAndReopen(CurrentOptions());
db_->Put(WriteOptions(), "key", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
ReadOptions read_opts;
std::string value;
ASSERT_TRUE(db_->Get(read_opts, "key", &value).IsNotFound());
} while (ChangeOptions(kRangeDelSkipConfigs));
}
TEST_F(DBRangeDelTest, GetCoveredKeyFromImmutableMemtable) {
do {
Options opts = CurrentOptions();
opts.max_write_buffer_number = 3;
opts.min_write_buffer_number_to_merge = 2;
// SpecialSkipListFactory lets us specify maximum number of elements the
// memtable can hold. It switches the active memtable to immutable (flush is
// prevented by the above options) upon inserting an element that would
// overflow the memtable.
opts.memtable_factory.reset(new SpecialSkipListFactory(1));
DestroyAndReopen(opts);
db_->Put(WriteOptions(), "key", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
db_->Put(WriteOptions(), "blah", "val");
ReadOptions read_opts;
std::string value;
ASSERT_TRUE(db_->Get(read_opts, "key", &value).IsNotFound());
} while (ChangeOptions(kRangeDelSkipConfigs));
}
TEST_F(DBRangeDelTest, GetCoveredKeyFromSst) {
do {
DestroyAndReopen(CurrentOptions());
db_->Put(WriteOptions(), "key", "val");
// snapshot prevents key from being deleted during flush
const Snapshot* snapshot = db_->GetSnapshot();
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
ASSERT_OK(db_->Flush(FlushOptions()));
ReadOptions read_opts;
std::string value;
ASSERT_TRUE(db_->Get(read_opts, "key", &value).IsNotFound());
db_->ReleaseSnapshot(snapshot);
} while (ChangeOptions(kRangeDelSkipConfigs));
}
TEST_F(DBRangeDelTest, GetCoveredMergeOperandFromMemtable) {
const int kNumMergeOps = 10;
Options opts = CurrentOptions();
opts.merge_operator = MergeOperators::CreateUInt64AddOperator();
Reopen(opts);
for (int i = 0; i < kNumMergeOps; ++i) {
std::string val;
PutFixed64(&val, i);
db_->Merge(WriteOptions(), "key", val);
if (i == kNumMergeOps / 2) {
// deletes [0, 5]
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "key",
"key_");
}
}
ReadOptions read_opts;
std::string expected, actual;
ASSERT_OK(db_->Get(read_opts, "key", &actual));
PutFixed64(&expected, 30); // 6+7+8+9
ASSERT_EQ(expected, actual);
expected.clear();
read_opts.ignore_range_deletions = true;
ASSERT_OK(db_->Get(read_opts, "key", &actual));
PutFixed64(&expected, 45); // 0+1+2+...+9
ASSERT_EQ(expected, actual);
}
TEST_F(DBRangeDelTest, GetIgnoresRangeDeletions) {
Options opts = CurrentOptions();
opts.max_write_buffer_number = 4;
opts.min_write_buffer_number_to_merge = 3;
opts.memtable_factory.reset(new SpecialSkipListFactory(1));
Reopen(opts);
db_->Put(WriteOptions(), "sst_key", "val");
// snapshot prevents key from being deleted during flush
const Snapshot* snapshot = db_->GetSnapshot();
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
ASSERT_OK(db_->Flush(FlushOptions()));
db_->Put(WriteOptions(), "imm_key", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
db_->Put(WriteOptions(), "mem_key", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
ReadOptions read_opts;
read_opts.ignore_range_deletions = true;
for (std::string key : {"sst_key", "imm_key", "mem_key"}) {
std::string value;
ASSERT_OK(db_->Get(read_opts, key, &value));
}
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, IteratorRemovesCoveredKeys) {
const int kNum = 200, kRangeBegin = 50, kRangeEnd = 150, kNumPerFile = 25;
Options opts = CurrentOptions();
opts.comparator = test::Uint64Comparator();
opts.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
Reopen(opts);
// Write half of the keys before the tombstone and half after the tombstone.
// Only covered keys (i.e., within the range and older than the tombstone)
// should be deleted.
for (int i = 0; i < kNum; ++i) {
if (i == kNum / 2) {
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
GetNumericStr(kRangeBegin), GetNumericStr(kRangeEnd));
}
db_->Put(WriteOptions(), GetNumericStr(i), "val");
}
ReadOptions read_opts;
auto* iter = db_->NewIterator(read_opts);
int expected = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
ASSERT_EQ(GetNumericStr(expected), iter->key());
if (expected == kRangeBegin - 1) {
expected = kNum / 2;
} else {
++expected;
}
}
ASSERT_EQ(kNum, expected);
delete iter;
}
TEST_F(DBRangeDelTest, IteratorOverUserSnapshot) {
const int kNum = 200, kRangeBegin = 50, kRangeEnd = 150, kNumPerFile = 25;
Options opts = CurrentOptions();
opts.comparator = test::Uint64Comparator();
opts.memtable_factory.reset(new SpecialSkipListFactory(kNumPerFile));
Reopen(opts);
const Snapshot* snapshot = nullptr;
// Put a snapshot before the range tombstone, verify an iterator using that
// snapshot sees all inserted keys.
for (int i = 0; i < kNum; ++i) {
if (i == kNum / 2) {
snapshot = db_->GetSnapshot();
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
GetNumericStr(kRangeBegin), GetNumericStr(kRangeEnd));
}
db_->Put(WriteOptions(), GetNumericStr(i), "val");
}
ReadOptions read_opts;
read_opts.snapshot = snapshot;
auto* iter = db_->NewIterator(read_opts);
int expected = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
ASSERT_EQ(GetNumericStr(expected), iter->key());
++expected;
}
ASSERT_EQ(kNum / 2, expected);
delete iter;
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, IteratorIgnoresRangeDeletions) {
Options opts = CurrentOptions();
opts.max_write_buffer_number = 4;
opts.min_write_buffer_number_to_merge = 3;
opts.memtable_factory.reset(new SpecialSkipListFactory(1));
Reopen(opts);
db_->Put(WriteOptions(), "sst_key", "val");
// snapshot prevents key from being deleted during flush
const Snapshot* snapshot = db_->GetSnapshot();
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
ASSERT_OK(db_->Flush(FlushOptions()));
db_->Put(WriteOptions(), "imm_key", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
db_->Put(WriteOptions(), "mem_key", "val");
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
ReadOptions read_opts;
read_opts.ignore_range_deletions = true;
auto* iter = db_->NewIterator(read_opts);
int i = 0;
std::string expected[] = {"imm_key", "mem_key", "sst_key"};
for (iter->SeekToFirst(); iter->Valid(); iter->Next(), ++i) {
std::string key;
ASSERT_EQ(expected[i], iter->key());
}
ASSERT_EQ(3, i);
delete iter;
db_->ReleaseSnapshot(snapshot);
}
#ifndef ROCKSDB_UBSAN_RUN
TEST_F(DBRangeDelTest, TailingIteratorRangeTombstoneUnsupported) {
db_->Put(WriteOptions(), "key", "val");
// snapshot prevents key from being deleted during flush
const Snapshot* snapshot = db_->GetSnapshot();
ASSERT_OK(
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "a", "z"));
// iterations check unsupported in memtable, l0, and then l1
for (int i = 0; i < 3; ++i) {
ReadOptions read_opts;
read_opts.tailing = true;
auto* iter = db_->NewIterator(read_opts);
if (i == 2) {
// For L1+, iterators over files are created on-demand, so need seek
iter->SeekToFirst();
}
ASSERT_TRUE(iter->status().IsNotSupported());
delete iter;
if (i == 0) {
ASSERT_OK(db_->Flush(FlushOptions()));
} else if (i == 1) {
MoveFilesToLevel(1);
}
}
db_->ReleaseSnapshot(snapshot);
}
#endif // !ROCKSDB_UBSAN_RUN
TEST_F(DBRangeDelTest, SubcompactionHasEmptyDedicatedRangeDelFile) {
const int kNumFiles = 2, kNumKeysPerFile = 4;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.disable_auto_compactions = true;
options.level0_file_num_compaction_trigger = kNumFiles;
options.max_subcompactions = 2;
options.num_levels = 2;
options.target_file_size_base = 4096;
Reopen(options);
// need a L1 file for subcompaction to be triggered
ASSERT_OK(
db_->Put(WriteOptions(), db_->DefaultColumnFamily(), Key(0), "val"));
ASSERT_OK(db_->Flush(FlushOptions()));
MoveFilesToLevel(1);
// put enough keys to fill up the first subcompaction, and later range-delete
// them so that the first subcompaction outputs no key-values. In that case
// it'll consider making an SST file dedicated to range deletions.
for (int i = 0; i < kNumKeysPerFile; ++i) {
ASSERT_OK(db_->Put(WriteOptions(), db_->DefaultColumnFamily(), Key(i),
std::string(1024, 'a')));
}
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), Key(0),
Key(kNumKeysPerFile)));
// the above range tombstone can be dropped, so that one alone won't cause a
// dedicated file to be opened. We can make one protected by snapshot that
// must be considered. Make its range outside the first subcompaction's range
// to exercise the tricky part of the code.
const Snapshot* snapshot = db_->GetSnapshot();
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
Key(kNumKeysPerFile + 1),
Key(kNumKeysPerFile + 2)));
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_EQ(kNumFiles, NumTableFilesAtLevel(0));
ASSERT_EQ(1, NumTableFilesAtLevel(1));
db_->EnableAutoCompaction({db_->DefaultColumnFamily()});
dbfull()->TEST_WaitForCompact();
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, MemtableBloomFilter) {
// regression test for #2743. the range delete tombstones in memtable should
// be added even when Get() skips searching due to its prefix bloom filter
const int kMemtableSize = 1 << 20; // 1MB
const int kMemtablePrefixFilterSize = 1 << 13; // 8KB
const int kNumKeys = 1000;
const int kPrefixLen = 8;
Options options = CurrentOptions();
options.memtable_prefix_bloom_size_ratio =
static_cast<double>(kMemtablePrefixFilterSize) / kMemtableSize;
options.prefix_extractor.reset(rocksdb::NewFixedPrefixTransform(kPrefixLen));
options.write_buffer_size = kMemtableSize;
Reopen(options);
for (int i = 0; i < kNumKeys; ++i) {
ASSERT_OK(Put(Key(i), "val"));
}
Flush();
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), Key(0),
Key(kNumKeys)));
for (int i = 0; i < kNumKeys; ++i) {
std::string value;
ASSERT_TRUE(db_->Get(ReadOptions(), Key(i), &value).IsNotFound());
}
}
TEST_F(DBRangeDelTest, CompactionTreatsSplitInputLevelDeletionAtomically) {
// This test originally verified that compaction treated files containing a
// split range deletion in the input level as an atomic unit. I.e.,
// compacting any input-level file(s) containing a portion of the range
// deletion causes all other input-level files containing portions of that
// same range deletion to be included in the compaction. Range deletion
// tombstones are now truncated to sstable boundaries which removed the need
// for that behavior (which could lead to excessively large
// compactions).
const int kNumFilesPerLevel = 4, kValueBytes = 4 << 10;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.level0_file_num_compaction_trigger = kNumFilesPerLevel;
options.memtable_factory.reset(
new SpecialSkipListFactory(2 /* num_entries_flush */));
options.target_file_size_base = kValueBytes;
// i == 0: CompactFiles
// i == 1: CompactRange
// i == 2: automatic compaction
for (int i = 0; i < 3; ++i) {
DestroyAndReopen(options);
ASSERT_OK(Put(Key(0), ""));
ASSERT_OK(db_->Flush(FlushOptions()));
MoveFilesToLevel(2);
ASSERT_EQ(1, NumTableFilesAtLevel(2));
// snapshot protects range tombstone from dropping due to becoming obsolete.
const Snapshot* snapshot = db_->GetSnapshot();
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), Key(0),
Key(2 * kNumFilesPerLevel));
Random rnd(301);
std::string value = RandomString(&rnd, kValueBytes);
for (int j = 0; j < kNumFilesPerLevel; ++j) {
// give files overlapping key-ranges to prevent trivial move
ASSERT_OK(Put(Key(j), value));
ASSERT_OK(Put(Key(2 * kNumFilesPerLevel - 1 - j), value));
if (j > 0) {
dbfull()->TEST_WaitForFlushMemTable();
ASSERT_EQ(j, NumTableFilesAtLevel(0));
}
}
// put extra key to trigger final flush
ASSERT_OK(Put("", ""));
dbfull()->TEST_WaitForFlushMemTable();
dbfull()->TEST_WaitForCompact();
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(kNumFilesPerLevel, NumTableFilesAtLevel(1));
ColumnFamilyMetaData meta;
db_->GetColumnFamilyMetaData(&meta);
if (i == 0) {
ASSERT_OK(db_->CompactFiles(
CompactionOptions(), {meta.levels[1].files[0].name}, 2 /* level */));
ASSERT_EQ(0, NumTableFilesAtLevel(1));
} else if (i == 1) {
auto begin_str = Key(0), end_str = Key(1);
Slice begin = begin_str, end = end_str;
ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &begin, &end));
ASSERT_EQ(3, NumTableFilesAtLevel(1));
} else if (i == 2) {
ASSERT_OK(db_->SetOptions(db_->DefaultColumnFamily(),
{{"max_bytes_for_level_base", "10000"}}));
dbfull()->TEST_WaitForCompact();
ASSERT_EQ(1, NumTableFilesAtLevel(1));
}
ASSERT_GT(NumTableFilesAtLevel(2), 0);
db_->ReleaseSnapshot(snapshot);
}
}
TEST_F(DBRangeDelTest, RangeTombstoneEndKeyAsSstableUpperBound) {
// Test the handling of the range-tombstone end-key as the
// upper-bound for an sstable.
const int kNumFilesPerLevel = 2, kValueBytes = 4 << 10;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.level0_file_num_compaction_trigger = kNumFilesPerLevel;
options.memtable_factory.reset(
new SpecialSkipListFactory(2 /* num_entries_flush */));
options.target_file_size_base = kValueBytes;
options.disable_auto_compactions = true;
DestroyAndReopen(options);
// Create an initial sstable at L2:
// [key000000#1,1, key000000#1,1]
ASSERT_OK(Put(Key(0), ""));
ASSERT_OK(db_->Flush(FlushOptions()));
MoveFilesToLevel(2);
ASSERT_EQ(1, NumTableFilesAtLevel(2));
// A snapshot protects the range tombstone from dropping due to
// becoming obsolete.
const Snapshot* snapshot = db_->GetSnapshot();
db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
Key(0), Key(2 * kNumFilesPerLevel));
// Create 2 additional sstables in L0. Note that the first sstable
// contains the range tombstone.
// [key000000#3,1, key000004#72057594037927935,15]
// [key000001#5,1, key000002#6,1]
Random rnd(301);
std::string value = RandomString(&rnd, kValueBytes);
for (int j = 0; j < kNumFilesPerLevel; ++j) {
// Give files overlapping key-ranges to prevent a trivial move when we
// compact from L0 to L1.
ASSERT_OK(Put(Key(j), value));
ASSERT_OK(Put(Key(2 * kNumFilesPerLevel - 1 - j), value));
ASSERT_OK(db_->Flush(FlushOptions()));
ASSERT_EQ(j + 1, NumTableFilesAtLevel(0));
}
// Compact the 2 L0 sstables to L1, resulting in the following LSM. There
// are 2 sstables generated in L1 due to the target_file_size_base setting.
// L1:
// [key000000#3,1, key000002#72057594037927935,15]
// [key000002#6,1, key000004#72057594037927935,15]
// L2:
// [key000000#1,1, key000000#1,1]
MoveFilesToLevel(1);
ASSERT_EQ(2, NumTableFilesAtLevel(1));
{
// Compact the second sstable in L1:
// L1:
// [key000000#3,1, key000002#72057594037927935,15]
// L2:
// [key000000#1,1, key000000#1,1]
// [key000002#6,1, key000004#72057594037927935,15]
//
// At the same time, verify the compaction does not cause the key at the
// endpoint (key000002#6,1) to disappear.
ASSERT_EQ(value, Get(Key(2)));
auto begin_str = Key(3);
const rocksdb::Slice begin = begin_str;
dbfull()->TEST_CompactRange(1, &begin, nullptr);
ASSERT_EQ(1, NumTableFilesAtLevel(1));
ASSERT_EQ(2, NumTableFilesAtLevel(2));
ASSERT_EQ(value, Get(Key(2)));
}
{
// Compact the first sstable in L1. This should be copacetic, but
// was previously resulting in overlapping sstables in L2 due to
// mishandling of the range tombstone end-key when used as the
// largest key for an sstable. The resulting LSM structure should
// be:
//
// L2:
// [key000000#1,1, key000001#72057594037927935,15]
// [key000001#5,1, key000002#72057594037927935,15]
// [key000002#6,1, key000004#72057594037927935,15]
auto begin_str = Key(0);
const rocksdb::Slice begin = begin_str;
dbfull()->TEST_CompactRange(1, &begin, &begin);
ASSERT_EQ(0, NumTableFilesAtLevel(1));
ASSERT_EQ(3, NumTableFilesAtLevel(2));
}
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, UnorderedTombstones) {
// Regression test for #2752. Range delete tombstones between
// different snapshot stripes are not stored in order, so the first
// tombstone of each snapshot stripe should be checked as a smallest
// candidate.
Options options = CurrentOptions();
DestroyAndReopen(options);
auto cf = db_->DefaultColumnFamily();
ASSERT_OK(db_->Put(WriteOptions(), cf, "a", "a"));
ASSERT_OK(db_->Flush(FlushOptions(), cf));
ASSERT_EQ(1, NumTableFilesAtLevel(0));
ASSERT_OK(dbfull()->TEST_CompactRange(0, nullptr, nullptr));
ASSERT_EQ(1, NumTableFilesAtLevel(1));
ASSERT_OK(db_->DeleteRange(WriteOptions(), cf, "b", "c"));
// Hold a snapshot to separate these two delete ranges.
auto snapshot = db_->GetSnapshot();
ASSERT_OK(db_->DeleteRange(WriteOptions(), cf, "a", "b"));
ASSERT_OK(db_->Flush(FlushOptions(), cf));
db_->ReleaseSnapshot(snapshot);
std::vector<std::vector<FileMetaData>> files;
dbfull()->TEST_GetFilesMetaData(cf, &files);
ASSERT_EQ(1, files[0].size());
ASSERT_EQ("a", files[0][0].smallest.user_key());
ASSERT_EQ("c", files[0][0].largest.user_key());
std::string v;
auto s = db_->Get(ReadOptions(), "a", &v);
ASSERT_TRUE(s.IsNotFound());
}
class MockMergeOperator : public MergeOperator {
// Mock non-associative operator. Non-associativity is expressed by lack of
// implementation for any `PartialMerge*` functions.
public:
virtual bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override {
assert(merge_out != nullptr);
merge_out->new_value = merge_in.operand_list.back().ToString();
return true;
}
virtual const char* Name() const override { return "MockMergeOperator"; }
};
TEST_F(DBRangeDelTest, KeyAtOverlappingEndpointReappears) {
// This test uses a non-associative merge operator since that is a convenient
// way to get compaction to write out files with overlapping user-keys at the
// endpoints. Note, however, overlapping endpoints can also occur with other
// value types (Put, etc.), assuming the right snapshots are present.
const int kFileBytes = 1 << 20;
const int kValueBytes = 1 << 10;
const int kNumFiles = 4;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.disable_auto_compactions = true;
options.merge_operator.reset(new MockMergeOperator());
options.target_file_size_base = kFileBytes;
Reopen(options);
// Push dummy data to L3 so that our actual test files on L0-L2
// will not be considered "bottommost" level, otherwise compaction
// may prevent us from creating overlapping user keys
// as on the bottommost layer MergeHelper
ASSERT_OK(db_->Merge(WriteOptions(), "key", "dummy"));
ASSERT_OK(db_->Flush(FlushOptions()));
MoveFilesToLevel(3);
Random rnd(301);
const Snapshot* snapshot = nullptr;
for (int i = 0; i < kNumFiles; ++i) {
for (int j = 0; j < kFileBytes / kValueBytes; ++j) {
auto value = RandomString(&rnd, kValueBytes);
ASSERT_OK(db_->Merge(WriteOptions(), "key", value));
}
if (i == kNumFiles - 1) {
// Take snapshot to prevent covered merge operands from being dropped by
// compaction.
snapshot = db_->GetSnapshot();
// The DeleteRange is the last write so all merge operands are covered.
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
"key", "key_"));
}
ASSERT_OK(db_->Flush(FlushOptions()));
}
ASSERT_EQ(kNumFiles, NumTableFilesAtLevel(0));
std::string value;
ASSERT_TRUE(db_->Get(ReadOptions(), "key", &value).IsNotFound());
dbfull()->TEST_CompactRange(0 /* level */, nullptr /* begin */,
nullptr /* end */, nullptr /* column_family */,
true /* disallow_trivial_move */);
ASSERT_EQ(0, NumTableFilesAtLevel(0));
// Now we have multiple files at L1 all containing a single user key, thus
// guaranteeing overlap in the file endpoints.
ASSERT_GT(NumTableFilesAtLevel(1), 1);
// Verify no merge operands reappeared after the compaction.
ASSERT_TRUE(db_->Get(ReadOptions(), "key", &value).IsNotFound());
// Compact and verify again. It's worthwhile because now the files have
// tighter endpoints, so we can verify that doesn't mess anything up.
dbfull()->TEST_CompactRange(1 /* level */, nullptr /* begin */,
nullptr /* end */, nullptr /* column_family */,
true /* disallow_trivial_move */);
ASSERT_GT(NumTableFilesAtLevel(2), 1);
ASSERT_TRUE(db_->Get(ReadOptions(), "key", &value).IsNotFound());
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, UntruncatedTombstoneDoesNotDeleteNewerKey) {
// Verify a key newer than a range tombstone cannot be deleted by being
// compacted to the bottom level (and thus having its seqnum zeroed) before
// the range tombstone. This used to happen when range tombstones were
// untruncated on reads such that they extended past their file boundaries.
//
// Test summary:
//
// - L1 is bottommost.
// - A couple snapshots are strategically taken to prevent seqnums from being
// zeroed, range tombstone from being dropped, merge operands from being
// dropped, and merge operands from being combined.
// - Left half of files in L1 all have same user key, ensuring their file
// boundaries overlap. In the past this would cause range tombstones to be
// untruncated.
// - Right half of L1 files all have different keys, ensuring no overlap.
// - A range tombstone spans all L1 keys, so it is stored in every L1 file.
// - Keys in the right side of the key-range are overwritten. These are
// compacted down to L1 after releasing snapshots such that their seqnums
// will be zeroed.
// - A full range scan is performed. If the tombstone in the left L1 files
// were untruncated, it would now cover keys newer than it (but with zeroed
// seqnums) in the right L1 files.
const int kFileBytes = 1 << 20;
const int kValueBytes = 1 << 10;
const int kNumFiles = 4;
const int kMaxKey = kNumFiles* kFileBytes / kValueBytes;
const int kKeysOverwritten = 10;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.disable_auto_compactions = true;
options.merge_operator.reset(new MockMergeOperator());
options.num_levels = 2;
options.target_file_size_base = kFileBytes;
Reopen(options);
Random rnd(301);
// - snapshots[0] prevents merge operands from being combined during
// compaction.
// - snapshots[1] prevents merge operands from being dropped due to the
// covering range tombstone.
const Snapshot* snapshots[] = {nullptr, nullptr};
for (int i = 0; i < kNumFiles; ++i) {
for (int j = 0; j < kFileBytes / kValueBytes; ++j) {
auto value = RandomString(&rnd, kValueBytes);
std::string key;
if (i < kNumFiles / 2) {
key = Key(0);
} else {
key = Key(1 + i * kFileBytes / kValueBytes + j);
}
ASSERT_OK(db_->Merge(WriteOptions(), key, value));
}
if (i == 0) {
snapshots[0] = db_->GetSnapshot();
}
if (i == kNumFiles - 1) {
snapshots[1] = db_->GetSnapshot();
// The DeleteRange is the last write so all merge operands are covered.
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
Key(0), Key(kMaxKey + 1)));
}
ASSERT_OK(db_->Flush(FlushOptions()));
}
ASSERT_EQ(kNumFiles, NumTableFilesAtLevel(0));
auto get_key_count = [this]() -> int {
auto* iter = db_->NewIterator(ReadOptions());
iter->SeekToFirst();
int keys_found = 0;
for (; iter->Valid(); iter->Next()) {
++keys_found;
}
delete iter;
return keys_found;
};
// All keys should be covered
ASSERT_EQ(0, get_key_count());
ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr /* begin_key */,
nullptr /* end_key */));
ASSERT_EQ(0, NumTableFilesAtLevel(0));
// Roughly the left half of L1 files should have overlapping boundary keys,
// while the right half should not.
ASSERT_GE(NumTableFilesAtLevel(1), kNumFiles);
// Now overwrite a few keys that are in L1 files that definitely don't have
// overlapping boundary keys.
for (int i = kMaxKey; i > kMaxKey - kKeysOverwritten; --i) {
auto value = RandomString(&rnd, kValueBytes);
ASSERT_OK(db_->Merge(WriteOptions(), Key(i), value));
}
ASSERT_OK(db_->Flush(FlushOptions()));
// The overwritten keys are in L0 now, so clearly aren't covered by the range
// tombstone in L1.
ASSERT_EQ(kKeysOverwritten, get_key_count());
// Release snapshots so seqnums can be zeroed when L0->L1 happens.
db_->ReleaseSnapshot(snapshots[0]);
db_->ReleaseSnapshot(snapshots[1]);
auto begin_key_storage = Key(kMaxKey - kKeysOverwritten + 1);
auto end_key_storage = Key(kMaxKey);
Slice begin_key(begin_key_storage);
Slice end_key(end_key_storage);
ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &begin_key, &end_key));
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_GE(NumTableFilesAtLevel(1), kNumFiles);
ASSERT_EQ(kKeysOverwritten, get_key_count());
}
TEST_F(DBRangeDelTest, DeletedMergeOperandReappearsIterPrev) {
// Exposes a bug where we were using
// `RangeDelPositioningMode::kBackwardTraversal` while scanning merge operands
// in the forward direction. Confusingly, this case happened during
// `DBIter::Prev`. It could cause assertion failure, or reappearing keys.
const int kFileBytes = 1 << 20;
const int kValueBytes = 1 << 10;
// Need multiple keys so we can get results when calling `Prev()` after
// `SeekToLast()`.
const int kNumKeys = 3;
const int kNumFiles = 4;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.disable_auto_compactions = true;
options.merge_operator.reset(new MockMergeOperator());
options.target_file_size_base = kFileBytes;
Reopen(options);
Random rnd(301);
const Snapshot* snapshot = nullptr;
for (int i = 0; i < kNumFiles; ++i) {
for (int j = 0; j < kFileBytes / kValueBytes; ++j) {
auto value = RandomString(&rnd, kValueBytes);
ASSERT_OK(db_->Merge(WriteOptions(), Key(j % kNumKeys), value));
if (i == 0 && j == kNumKeys) {
// Take snapshot to prevent covered merge operands from being dropped or
// merged by compaction.
snapshot = db_->GetSnapshot();
// Do a DeleteRange near the beginning so only the oldest merge operand
// for each key is covered. This ensures the sequence of events:
//
// - `DBIter::Prev()` is called
// - After several same versions of the same user key are encountered,
// it decides to seek using `DBIter::FindValueForCurrentKeyUsingSeek`.
// - Binary searches to the newest version of the key, which is in the
// leftmost file containing the user key.
// - Scans forwards to collect all merge operands. Eventually reaches
// the rightmost file containing the oldest merge operand, which
// should be covered by the `DeleteRange`. If `RangeDelAggregator`
// were not properly using `kForwardTraversal` here, that operand
// would reappear.
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
Key(0), Key(kNumKeys + 1)));
}
}
ASSERT_OK(db_->Flush(FlushOptions()));
}
ASSERT_EQ(kNumFiles, NumTableFilesAtLevel(0));
ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr /* begin_key */,
nullptr /* end_key */));
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_GT(NumTableFilesAtLevel(1), 1);
auto* iter = db_->NewIterator(ReadOptions());
iter->SeekToLast();
int keys_found = 0;
for (; iter->Valid(); iter->Prev()) {
++keys_found;
}
delete iter;
ASSERT_EQ(kNumKeys, keys_found);
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, SnapshotPreventsDroppedKeys) {
const int kFileBytes = 1 << 20;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.disable_auto_compactions = true;
options.target_file_size_base = kFileBytes;
Reopen(options);
ASSERT_OK(Put(Key(0), "a"));
const Snapshot* snapshot = db_->GetSnapshot();
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), Key(0),
Key(10)));
db_->Flush(FlushOptions());
ReadOptions read_opts;
read_opts.snapshot = snapshot;
auto* iter = db_->NewIterator(read_opts);
iter->SeekToFirst();
ASSERT_TRUE(iter->Valid());
ASSERT_EQ(Key(0), iter->key());
iter->Next();
ASSERT_FALSE(iter->Valid());
delete iter;
db_->ReleaseSnapshot(snapshot);
}
TEST_F(DBRangeDelTest, RangeTombstoneWrittenToMinimalSsts) {
// Adapted from
// https://github.com/cockroachdb/cockroach/blob/de8b3ea603dd1592d9dc26443c2cc92c356fbc2f/pkg/storage/engine/rocksdb_test.go#L1267-L1398.
// Regression test for issue where range tombstone was written to more files
// than necessary when it began exactly at the begin key in the next
// compaction output file.
const int kFileBytes = 1 << 20;
const int kValueBytes = 4 << 10;
Options options = CurrentOptions();
options.compression = kNoCompression;
options.disable_auto_compactions = true;
// Have a bit of slack in the size limits but we enforce them more strictly
// when manually flushing/compacting.
options.max_compaction_bytes = 2 * kFileBytes;
options.target_file_size_base = 2 * kFileBytes;
options.write_buffer_size = 2 * kFileBytes;
Reopen(options);
Random rnd(301);
for (char first_char : {'a', 'b', 'c'}) {
for (int i = 0; i < kFileBytes / kValueBytes; ++i) {
std::string key(1, first_char);
key.append(Key(i));
std::string value = RandomString(&rnd, kValueBytes);
ASSERT_OK(Put(key, value));
}
db_->Flush(FlushOptions());
MoveFilesToLevel(2);
}
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(3, NumTableFilesAtLevel(2));
// Populate the memtable lightly while spanning the whole key-space. The
// setting of `max_compaction_bytes` will cause the L0->L1 to output multiple
// files to prevent a large L1->L2 compaction later.
ASSERT_OK(Put("a", "val"));
ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
"c" + Key(1), "d"));
// Our compaction output file cutting logic currently only considers point
// keys. So, in order for the range tombstone to have a chance at landing at
// the start of a new file, we need a point key at the range tombstone's
// start.
// TODO(ajkr): remove this `Put` after file cutting accounts for range
// tombstones (#3977).
ASSERT_OK(Put("c" + Key(1), "value"));
db_->Flush(FlushOptions());
// Ensure manual L0->L1 compaction cuts the outputs before the range tombstone
// and the range tombstone is only placed in the second SST.
std::string begin_key_storage("c" + Key(1));
Slice begin_key(begin_key_storage);
std::string end_key_storage("d");
Slice end_key(end_key_storage);
dbfull()->TEST_CompactRange(0 /* level */, &begin_key /* begin */,
&end_key /* end */, nullptr /* column_family */,
true /* disallow_trivial_move */);
ASSERT_EQ(2, NumTableFilesAtLevel(1));
std::vector<LiveFileMetaData> all_metadata;
std::vector<LiveFileMetaData> l1_metadata;
db_->GetLiveFilesMetaData(&all_metadata);
for (const auto& metadata : all_metadata) {
if (metadata.level == 1) {
l1_metadata.push_back(metadata);
}
}
std::sort(l1_metadata.begin(), l1_metadata.end(),
[&](const LiveFileMetaData& a, const LiveFileMetaData& b) {
return options.comparator->Compare(a.smallestkey, b.smallestkey) <
0;
});
ASSERT_EQ("a", l1_metadata[0].smallestkey);
ASSERT_EQ("a", l1_metadata[0].largestkey);
ASSERT_EQ("c" + Key(1), l1_metadata[1].smallestkey);
ASSERT_EQ("d", l1_metadata[1].largestkey);
TablePropertiesCollection all_table_props;
ASSERT_OK(db_->GetPropertiesOfAllTables(&all_table_props));
int64_t num_range_deletions = 0;
for (const auto& name_and_table_props : all_table_props) {
const auto& name = name_and_table_props.first;
const auto& table_props = name_and_table_props.second;
// The range tombstone should only be output to the second L1 SST.
if (name.size() >= l1_metadata[1].name.size() &&
name.substr(name.size() - l1_metadata[1].name.size()).compare(l1_metadata[1].name) == 0) {
ASSERT_EQ(1, table_props->num_range_deletions);
++num_range_deletions;
} else {
ASSERT_EQ(0, table_props->num_range_deletions);
}
}
ASSERT_EQ(1, num_range_deletions);
}
#endif // ROCKSDB_LITE
} // namespace rocksdb
int main(int argc, char** argv) {
rocksdb::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
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