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rocksdb/db/memtable_list_test.cc
Abhishek Madan 8c78348c77 Use only "local" range tombstones during Get (#4449) 
Summary:
Previously, range tombstones were accumulated from every level, which
was necessary if a range tombstone in a higher level covered a key in a lower
level. However, RangeDelAggregator::AddTombstones's complexity is based on
the number of tombstones that are currently stored in it, which is wasteful in
the Get case, where we only need to know the highest sequence number of range
tombstones that cover the key from higher levels, and compute the highest covering
sequence number at the current level. This change introduces this optimization, and
removes the use of RangeDelAggregator from the Get path.

In the benchmark results, the following command was used to initialize the database:
```
./db_bench -db=/dev/shm/5k-rts -use_existing_db=false -benchmarks=filluniquerandom -write_buffer_size=1048576 -compression_type=lz4 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -value_size=112 -key_size=16 -block_size=4096 -level_compaction_dynamic_level_bytes=true -num=5000000 -max_background_jobs=12 -benchmark_write_rate_limit=20971520 -range_tombstone_width=100 -writes_per_range_tombstone=100 -max_num_range_tombstones=50000 -bloom_bits=8
```

...and the following command was used to measure read throughput:
```
./db_bench -db=/dev/shm/5k-rts/ -use_existing_db=true -benchmarks=readrandom -disable_auto_compactions=true -num=5000000 -reads=100000 -threads=32
```

The filluniquerandom command was only run once, and the resulting database was used
to measure read performance before and after the PR. Both binaries were compiled with
`DEBUG_LEVEL=0`.

Readrandom results before PR:
```
readrandom   :       4.544 micros/op 220090 ops/sec;   16.9 MB/s (63103 of 100000 found)
```

Readrandom results after PR:
```
readrandom   :      11.147 micros/op 89707 ops/sec;    6.9 MB/s (63103 of 100000 found)
```

So it's actually slower right now, but this PR paves the way for future optimizations (see #4493).

----
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4449

Differential Revision: D10370575

Pulled By: abhimadan

fbshipit-source-id: 9a2e152be1ef36969055c0e9eb4beb0d96c11f4d
2018-10-24 12:31:12 -07:00

1064 lines
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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "db/memtable_list.h"
#include <algorithm>
#include <string>
#include <vector>
#include "db/merge_context.h"
#include "db/range_del_aggregator.h"
#include "db/version_set.h"
#include "db/write_controller.h"
#include "rocksdb/db.h"
#include "rocksdb/status.h"
#include "rocksdb/write_buffer_manager.h"
#include "util/string_util.h"
#include "util/testharness.h"
#include "util/testutil.h"
namespace rocksdb {
class MemTableListTest : public testing::Test {
public:
std::string dbname;
DB* db;
Options options;
std::vector<ColumnFamilyHandle*> handles;
std::atomic<uint64_t> file_number;
MemTableListTest() : db(nullptr), file_number(1) {
dbname = test::PerThreadDBPath("memtable_list_test");
options.create_if_missing = true;
DestroyDB(dbname, options);
}
// Create a test db if not yet created
void CreateDB() {
if (db == nullptr) {
options.create_if_missing = true;
DestroyDB(dbname, options);
// Open DB only with default column family
ColumnFamilyOptions cf_options;
std::vector<ColumnFamilyDescriptor> cf_descs;
cf_descs.emplace_back(kDefaultColumnFamilyName, cf_options);
Status s = DB::Open(options, dbname, cf_descs, &handles, &db);
EXPECT_OK(s);
ColumnFamilyOptions cf_opt1, cf_opt2;
cf_opt1.cf_paths.emplace_back(dbname + "_one_1",
std::numeric_limits<uint64_t>::max());
cf_opt2.cf_paths.emplace_back(dbname + "_two_1",
std::numeric_limits<uint64_t>::max());
int sz = static_cast<int>(handles.size());
handles.resize(sz + 2);
s = db->CreateColumnFamily(cf_opt1, "one", &handles[1]);
EXPECT_OK(s);
s = db->CreateColumnFamily(cf_opt2, "two", &handles[2]);
EXPECT_OK(s);
cf_descs.emplace_back("one", cf_options);
cf_descs.emplace_back("two", cf_options);
}
}
~MemTableListTest() {
if (db) {
std::vector<ColumnFamilyDescriptor> cf_descs(handles.size());
for (int i = 0; i != static_cast<int>(handles.size()); ++i) {
handles[i]->GetDescriptor(&cf_descs[i]);
}
for (auto h : handles) {
if (h) {
db->DestroyColumnFamilyHandle(h);
}
}
handles.clear();
delete db;
db = nullptr;
DestroyDB(dbname, options, cf_descs);
}
}
// Calls MemTableList::TryInstallMemtableFlushResults() and sets up all
// structures needed to call this function.
Status Mock_InstallMemtableFlushResults(
MemTableList* list, const MutableCFOptions& mutable_cf_options,
const autovector<MemTable*>& m, autovector<MemTable*>* to_delete) {
autovector<MemTableList*> lists;
lists.emplace_back(list);
autovector<const autovector<MemTable*>*> mems_list;
mems_list.emplace_back(&m);
return Mock_InstallMemtableFlushResults(
lists, {0} /* cf_ids */, {&mutable_cf_options}, mems_list, to_delete);
}
// Calls MemTableList::InstallMemtableFlushResults() and sets up all
// structures needed to call this function.
Status Mock_InstallMemtableFlushResults(
autovector<MemTableList*>& lists, const autovector<uint32_t>& cf_ids,
const autovector<const MutableCFOptions*>& mutable_cf_options_list,
const autovector<const autovector<MemTable*>*>& mems_list,
autovector<MemTable*>* to_delete) {
// Create a mock Logger
test::NullLogger logger;
LogBuffer log_buffer(DEBUG_LEVEL, &logger);
CreateDB();
// Create a mock VersionSet
DBOptions db_options;
ImmutableDBOptions immutable_db_options(db_options);
EnvOptions env_options;
shared_ptr<Cache> table_cache(NewLRUCache(50000, 16));
WriteBufferManager write_buffer_manager(db_options.db_write_buffer_size);
WriteController write_controller(10000000u);
VersionSet versions(dbname, &immutable_db_options, env_options,
table_cache.get(), &write_buffer_manager,
&write_controller);
std::vector<ColumnFamilyDescriptor> cf_descs;
cf_descs.emplace_back(kDefaultColumnFamilyName, ColumnFamilyOptions());
cf_descs.emplace_back("one", ColumnFamilyOptions());
cf_descs.emplace_back("two", ColumnFamilyOptions());
EXPECT_OK(versions.Recover(cf_descs, false));
// Create mock default ColumnFamilyData
auto column_family_set = versions.GetColumnFamilySet();
LogsWithPrepTracker dummy_prep_tracker;
if (1 == cf_ids.size()) {
auto cfd = column_family_set->GetColumnFamily(cf_ids[0]);
EXPECT_TRUE(nullptr != cfd);
EXPECT_EQ(1, lists.size());
MemTableList* list = lists[0];
EXPECT_EQ(1, mutable_cf_options_list.size());
const MutableCFOptions& mutable_cf_options =
*(mutable_cf_options_list.at(0));
const autovector<MemTable*>* mems = mems_list.at(0);
EXPECT_TRUE(nullptr != mems);
uint64_t file_num = file_number.fetch_add(1);
// Create dummy mutex.
InstrumentedMutex mutex;
InstrumentedMutexLock l(&mutex);
return list->TryInstallMemtableFlushResults(
cfd, mutable_cf_options, *mems, &dummy_prep_tracker, &versions,
&mutex, file_num, to_delete, nullptr, &log_buffer);
}
autovector<ColumnFamilyData*> cfds;
for (int i = 0; i != static_cast<int>(cf_ids.size()); ++i) {
cfds.emplace_back(column_family_set->GetColumnFamily(cf_ids[i]));
EXPECT_NE(nullptr, cfds[i]);
}
autovector<FileMetaData> file_metas;
for (size_t i = 0; i != cf_ids.size(); ++i) {
FileMetaData meta;
uint64_t file_num = file_number.fetch_add(1);
meta.fd = FileDescriptor(file_num, 0, 0);
file_metas.emplace_back(meta);
}
bool atomic_flush_commit_in_progress = false;
InstrumentedMutex mutex;
InstrumentedMutexLock l(&mutex);
return MemTableList::TryInstallMemtableFlushResults(
lists, cfds, mutable_cf_options_list, mems_list,
&atomic_flush_commit_in_progress, &dummy_prep_tracker, &versions,
&mutex, file_metas, to_delete, nullptr, &log_buffer);
}
};
TEST_F(MemTableListTest, Empty) {
// Create an empty MemTableList and validate basic functions.
MemTableList list(1, 0);
ASSERT_EQ(0, list.NumNotFlushed());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
ASSERT_FALSE(list.IsFlushPending());
autovector<MemTable*> mems;
list.PickMemtablesToFlush(nullptr /* memtable_id */, &mems);
ASSERT_EQ(0, mems.size());
autovector<MemTable*> to_delete;
list.current()->Unref(&to_delete);
ASSERT_EQ(0, to_delete.size());
}
TEST_F(MemTableListTest, GetTest) {
// Create MemTableList
int min_write_buffer_number_to_merge = 2;
int max_write_buffer_number_to_maintain = 0;
MemTableList list(min_write_buffer_number_to_merge,
max_write_buffer_number_to_maintain);
SequenceNumber seq = 1;
std::string value;
Status s;
MergeContext merge_context;
InternalKeyComparator ikey_cmp(options.comparator);
SequenceNumber max_covering_tombstone_seq = 0;
autovector<MemTable*> to_delete;
LookupKey lkey("key1", seq);
bool found = list.current()->Get(lkey, &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
// Create a MemTable
InternalKeyComparator cmp(BytewiseComparator());
auto factory = std::make_shared<SkipListFactory>();
options.memtable_factory = factory;
ImmutableCFOptions ioptions(options);
WriteBufferManager wb(options.db_write_buffer_size);
MemTable* mem = new MemTable(cmp, ioptions, MutableCFOptions(options), &wb,
kMaxSequenceNumber, 0 /* column_family_id */);
mem->Ref();
// Write some keys to this memtable.
mem->Add(++seq, kTypeDeletion, "key1", "");
mem->Add(++seq, kTypeValue, "key2", "value2");
mem->Add(++seq, kTypeValue, "key1", "value1");
mem->Add(++seq, kTypeValue, "key2", "value2.2");
// Fetch the newly written keys
merge_context.Clear();
found = mem->Get(LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(s.ok() && found);
ASSERT_EQ(value, "value1");
merge_context.Clear();
found = mem->Get(LookupKey("key1", 2), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
// MemTable found out that this key is *not* found (at this sequence#)
ASSERT_TRUE(found && s.IsNotFound());
merge_context.Clear();
found = mem->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(s.ok() && found);
ASSERT_EQ(value, "value2.2");
ASSERT_EQ(4, mem->num_entries());
ASSERT_EQ(1, mem->num_deletes());
// Add memtable to list
list.Add(mem, &to_delete);
SequenceNumber saved_seq = seq;
// Create another memtable and write some keys to it
WriteBufferManager wb2(options.db_write_buffer_size);
MemTable* mem2 = new MemTable(cmp, ioptions, MutableCFOptions(options), &wb2,
kMaxSequenceNumber, 0 /* column_family_id */);
mem2->Ref();
mem2->Add(++seq, kTypeDeletion, "key1", "");
mem2->Add(++seq, kTypeValue, "key2", "value2.3");
// Add second memtable to list
list.Add(mem2, &to_delete);
// Fetch keys via MemTableList
merge_context.Clear();
found =
list.current()->Get(LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(found && s.IsNotFound());
merge_context.Clear();
found = list.current()->Get(LookupKey("key1", saved_seq), &value, &s,
&merge_context, &max_covering_tombstone_seq,
ReadOptions());
ASSERT_TRUE(s.ok() && found);
ASSERT_EQ("value1", value);
merge_context.Clear();
found =
list.current()->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(s.ok() && found);
ASSERT_EQ(value, "value2.3");
merge_context.Clear();
found = list.current()->Get(LookupKey("key2", 1), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
ASSERT_EQ(2, list.NumNotFlushed());
list.current()->Unref(&to_delete);
for (MemTable* m : to_delete) {
delete m;
}
}
TEST_F(MemTableListTest, GetFromHistoryTest) {
// Create MemTableList
int min_write_buffer_number_to_merge = 2;
int max_write_buffer_number_to_maintain = 2;
MemTableList list(min_write_buffer_number_to_merge,
max_write_buffer_number_to_maintain);
SequenceNumber seq = 1;
std::string value;
Status s;
MergeContext merge_context;
InternalKeyComparator ikey_cmp(options.comparator);
SequenceNumber max_covering_tombstone_seq = 0;
autovector<MemTable*> to_delete;
LookupKey lkey("key1", seq);
bool found = list.current()->Get(lkey, &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
// Create a MemTable
InternalKeyComparator cmp(BytewiseComparator());
auto factory = std::make_shared<SkipListFactory>();
options.memtable_factory = factory;
ImmutableCFOptions ioptions(options);
WriteBufferManager wb(options.db_write_buffer_size);
MemTable* mem = new MemTable(cmp, ioptions, MutableCFOptions(options), &wb,
kMaxSequenceNumber, 0 /* column_family_id */);
mem->Ref();
// Write some keys to this memtable.
mem->Add(++seq, kTypeDeletion, "key1", "");
mem->Add(++seq, kTypeValue, "key2", "value2");
mem->Add(++seq, kTypeValue, "key2", "value2.2");
// Fetch the newly written keys
merge_context.Clear();
found = mem->Get(LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
// MemTable found out that this key is *not* found (at this sequence#)
ASSERT_TRUE(found && s.IsNotFound());
merge_context.Clear();
found = mem->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(s.ok() && found);
ASSERT_EQ(value, "value2.2");
// Add memtable to list
list.Add(mem, &to_delete);
ASSERT_EQ(0, to_delete.size());
// Fetch keys via MemTableList
merge_context.Clear();
found =
list.current()->Get(LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(found && s.IsNotFound());
merge_context.Clear();
found =
list.current()->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(s.ok() && found);
ASSERT_EQ("value2.2", value);
// Flush this memtable from the list.
// (It will then be a part of the memtable history).
autovector<MemTable*> to_flush;
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
ASSERT_EQ(1, to_flush.size());
MutableCFOptions mutable_cf_options(options);
s = Mock_InstallMemtableFlushResults(&list, mutable_cf_options, to_flush,
&to_delete);
ASSERT_OK(s);
ASSERT_EQ(0, list.NumNotFlushed());
ASSERT_EQ(1, list.NumFlushed());
ASSERT_EQ(0, to_delete.size());
// Verify keys are no longer in MemTableList
merge_context.Clear();
found =
list.current()->Get(LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
merge_context.Clear();
found =
list.current()->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
// Verify keys are present in history
merge_context.Clear();
found = list.current()->GetFromHistory(
LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(found && s.IsNotFound());
merge_context.Clear();
found = list.current()->GetFromHistory(
LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(found);
ASSERT_EQ("value2.2", value);
// Create another memtable and write some keys to it
WriteBufferManager wb2(options.db_write_buffer_size);
MemTable* mem2 = new MemTable(cmp, ioptions, MutableCFOptions(options), &wb2,
kMaxSequenceNumber, 0 /* column_family_id */);
mem2->Ref();
mem2->Add(++seq, kTypeDeletion, "key1", "");
mem2->Add(++seq, kTypeValue, "key3", "value3");
// Add second memtable to list
list.Add(mem2, &to_delete);
ASSERT_EQ(0, to_delete.size());
to_flush.clear();
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
ASSERT_EQ(1, to_flush.size());
// Flush second memtable
s = Mock_InstallMemtableFlushResults(&list, mutable_cf_options, to_flush,
&to_delete);
ASSERT_OK(s);
ASSERT_EQ(0, list.NumNotFlushed());
ASSERT_EQ(2, list.NumFlushed());
ASSERT_EQ(0, to_delete.size());
// Add a third memtable to push the first memtable out of the history
WriteBufferManager wb3(options.db_write_buffer_size);
MemTable* mem3 = new MemTable(cmp, ioptions, MutableCFOptions(options), &wb3,
kMaxSequenceNumber, 0 /* column_family_id */);
mem3->Ref();
list.Add(mem3, &to_delete);
ASSERT_EQ(1, list.NumNotFlushed());
ASSERT_EQ(1, list.NumFlushed());
ASSERT_EQ(1, to_delete.size());
// Verify keys are no longer in MemTableList
merge_context.Clear();
found =
list.current()->Get(LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
merge_context.Clear();
found =
list.current()->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
merge_context.Clear();
found =
list.current()->Get(LookupKey("key3", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
// Verify that the second memtable's keys are in the history
merge_context.Clear();
found = list.current()->GetFromHistory(
LookupKey("key1", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(found && s.IsNotFound());
merge_context.Clear();
found = list.current()->GetFromHistory(
LookupKey("key3", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_TRUE(found);
ASSERT_EQ("value3", value);
// Verify that key2 from the first memtable is no longer in the history
merge_context.Clear();
found =
list.current()->Get(LookupKey("key2", seq), &value, &s, &merge_context,
&max_covering_tombstone_seq, ReadOptions());
ASSERT_FALSE(found);
// Cleanup
list.current()->Unref(&to_delete);
ASSERT_EQ(3, to_delete.size());
for (MemTable* m : to_delete) {
delete m;
}
}
TEST_F(MemTableListTest, FlushPendingTest) {
const int num_tables = 6;
SequenceNumber seq = 1;
Status s;
auto factory = std::make_shared<SkipListFactory>();
options.memtable_factory = factory;
ImmutableCFOptions ioptions(options);
InternalKeyComparator cmp(BytewiseComparator());
WriteBufferManager wb(options.db_write_buffer_size);
autovector<MemTable*> to_delete;
// Create MemTableList
int min_write_buffer_number_to_merge = 3;
int max_write_buffer_number_to_maintain = 7;
MemTableList list(min_write_buffer_number_to_merge,
max_write_buffer_number_to_maintain);
// Create some MemTables
uint64_t memtable_id = 0;
std::vector<MemTable*> tables;
MutableCFOptions mutable_cf_options(options);
for (int i = 0; i < num_tables; i++) {
MemTable* mem = new MemTable(cmp, ioptions, mutable_cf_options, &wb,
kMaxSequenceNumber, 0 /* column_family_id */);
mem->SetID(memtable_id++);
mem->Ref();
std::string value;
MergeContext merge_context;
mem->Add(++seq, kTypeValue, "key1", ToString(i));
mem->Add(++seq, kTypeValue, "keyN" + ToString(i), "valueN");
mem->Add(++seq, kTypeValue, "keyX" + ToString(i), "value");
mem->Add(++seq, kTypeValue, "keyM" + ToString(i), "valueM");
mem->Add(++seq, kTypeDeletion, "keyX" + ToString(i), "");
tables.push_back(mem);
}
// Nothing to flush
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
autovector<MemTable*> to_flush;
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
ASSERT_EQ(0, to_flush.size());
// Request a flush even though there is nothing to flush
list.FlushRequested();
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Attempt to 'flush' to clear request for flush
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
ASSERT_EQ(0, to_flush.size());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Request a flush again
list.FlushRequested();
// No flush pending since the list is empty.
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Add 2 tables
list.Add(tables[0], &to_delete);
list.Add(tables[1], &to_delete);
ASSERT_EQ(2, list.NumNotFlushed());
ASSERT_EQ(0, to_delete.size());
// Even though we have less than the minimum to flush, a flush is
// pending since we had previously requested a flush and never called
// PickMemtablesToFlush() to clear the flush.
ASSERT_TRUE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
// Pick tables to flush
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
ASSERT_EQ(2, to_flush.size());
ASSERT_EQ(2, list.NumNotFlushed());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Revert flush
list.RollbackMemtableFlush(to_flush, 0);
ASSERT_FALSE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
to_flush.clear();
// Add another table
list.Add(tables[2], &to_delete);
// We now have the minimum to flush regardles of whether FlushRequested()
// was called.
ASSERT_TRUE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
ASSERT_EQ(0, to_delete.size());
// Pick tables to flush
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
ASSERT_EQ(3, to_flush.size());
ASSERT_EQ(3, list.NumNotFlushed());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Pick tables to flush again
autovector<MemTable*> to_flush2;
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush2);
ASSERT_EQ(0, to_flush2.size());
ASSERT_EQ(3, list.NumNotFlushed());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Add another table
list.Add(tables[3], &to_delete);
ASSERT_FALSE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
ASSERT_EQ(0, to_delete.size());
// Request a flush again
list.FlushRequested();
ASSERT_TRUE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
// Pick tables to flush again
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush2);
ASSERT_EQ(1, to_flush2.size());
ASSERT_EQ(4, list.NumNotFlushed());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Rollback first pick of tables
list.RollbackMemtableFlush(to_flush, 0);
ASSERT_TRUE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
to_flush.clear();
// Add another tables
list.Add(tables[4], &to_delete);
ASSERT_EQ(5, list.NumNotFlushed());
// We now have the minimum to flush regardles of whether FlushRequested()
ASSERT_TRUE(list.IsFlushPending());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
ASSERT_EQ(0, to_delete.size());
// Pick tables to flush
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush);
// Should pick 4 of 5 since 1 table has been picked in to_flush2
ASSERT_EQ(4, to_flush.size());
ASSERT_EQ(5, list.NumNotFlushed());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Pick tables to flush again
autovector<MemTable*> to_flush3;
list.PickMemtablesToFlush(nullptr /* memtable_id */, &to_flush3);
ASSERT_EQ(0, to_flush3.size()); // nothing not in progress of being flushed
ASSERT_EQ(5, list.NumNotFlushed());
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Flush the 4 memtables that were picked in to_flush
s = Mock_InstallMemtableFlushResults(&list, mutable_cf_options, to_flush,
&to_delete);
ASSERT_OK(s);
// Note: now to_flush contains tables[0,1,2,4]. to_flush2 contains
// tables[3].
// Current implementation will only commit memtables in the order they were
// created. So TryInstallMemtableFlushResults will install the first 3 tables
// in to_flush and stop when it encounters a table not yet flushed.
ASSERT_EQ(2, list.NumNotFlushed());
int num_in_history = std::min(3, max_write_buffer_number_to_maintain);
ASSERT_EQ(num_in_history, list.NumFlushed());
ASSERT_EQ(5 - list.NumNotFlushed() - num_in_history, to_delete.size());
// Request a flush again. Should be nothing to flush
list.FlushRequested();
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
// Flush the 1 memtable that was picked in to_flush2
s = MemTableListTest::Mock_InstallMemtableFlushResults(
&list, mutable_cf_options, to_flush2, &to_delete);
ASSERT_OK(s);
// This will actually install 2 tables. The 1 we told it to flush, and also
// tables[4] which has been waiting for tables[3] to commit.
ASSERT_EQ(0, list.NumNotFlushed());
num_in_history = std::min(5, max_write_buffer_number_to_maintain);
ASSERT_EQ(num_in_history, list.NumFlushed());
ASSERT_EQ(5 - list.NumNotFlushed() - num_in_history, to_delete.size());
for (const auto& m : to_delete) {
// Refcount should be 0 after calling TryInstallMemtableFlushResults.
// Verify this, by Ref'ing then UnRef'ing:
m->Ref();
ASSERT_EQ(m, m->Unref());
delete m;
}
to_delete.clear();
// Add another table
list.Add(tables[5], &to_delete);
ASSERT_EQ(1, list.NumNotFlushed());
ASSERT_EQ(5, list.GetLatestMemTableID());
memtable_id = 4;
// Pick tables to flush. The tables to pick must have ID smaller than or
// equal to 4. Therefore, no table will be selected in this case.
autovector<MemTable*> to_flush4;
list.FlushRequested();
ASSERT_TRUE(list.HasFlushRequested());
list.PickMemtablesToFlush(&memtable_id, &to_flush4);
ASSERT_TRUE(to_flush4.empty());
ASSERT_EQ(1, list.NumNotFlushed());
ASSERT_TRUE(list.imm_flush_needed.load(std::memory_order_acquire));
ASSERT_FALSE(list.IsFlushPending());
ASSERT_FALSE(list.HasFlushRequested());
// Pick tables to flush. The tables to pick must have ID smaller than or
// equal to 5. Therefore, only tables[5] will be selected.
memtable_id = 5;
list.FlushRequested();
list.PickMemtablesToFlush(&memtable_id, &to_flush4);
ASSERT_EQ(1, static_cast<int>(to_flush4.size()));
ASSERT_EQ(1, list.NumNotFlushed());
ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
ASSERT_FALSE(list.IsFlushPending());
to_delete.clear();
list.current()->Unref(&to_delete);
int to_delete_size =
std::min(num_tables, max_write_buffer_number_to_maintain);
ASSERT_EQ(to_delete_size, to_delete.size());
for (const auto& m : to_delete) {
// Refcount should be 0 after calling TryInstallMemtableFlushResults.
// Verify this, by Ref'ing then UnRef'ing:
m->Ref();
ASSERT_EQ(m, m->Unref());
delete m;
}
to_delete.clear();
}
TEST_F(MemTableListTest, FlushMultipleCFsTest) {
const int num_cfs = 3;
const int num_tables_per_cf = 5;
SequenceNumber seq = 1;
Status s;
auto factory = std::make_shared<SkipListFactory>();
options.memtable_factory = factory;
ImmutableCFOptions ioptions(options);
InternalKeyComparator cmp(BytewiseComparator());
WriteBufferManager wb(options.db_write_buffer_size);
autovector<MemTable*> to_delete;
// Create MemTableLists
int min_write_buffer_number_to_merge = 3;
int max_write_buffer_number_to_maintain = 7;
autovector<MemTableList*> lists;
for (int i = 0; i != num_cfs; ++i) {
lists.emplace_back(new MemTableList(min_write_buffer_number_to_merge,
max_write_buffer_number_to_maintain));
}
autovector<uint32_t> cf_ids;
std::vector<std::vector<MemTable*>> tables(num_cfs);
autovector<const MutableCFOptions*> mutable_cf_options_list;
uint32_t cf_id = 0;
for (auto& elem : tables) {
mutable_cf_options_list.emplace_back(new MutableCFOptions(options));
uint64_t memtable_id = 0;
for (int i = 0; i != num_tables_per_cf; ++i) {
MemTable* mem =
new MemTable(cmp, ioptions, *(mutable_cf_options_list.back()), &wb,
kMaxSequenceNumber, cf_id);
mem->SetID(memtable_id++);
mem->Ref();
std::string value;
mem->Add(++seq, kTypeValue, "key1", ToString(i));
mem->Add(++seq, kTypeValue, "keyN" + ToString(i), "valueN");
mem->Add(++seq, kTypeValue, "keyX" + ToString(i), "value");
mem->Add(++seq, kTypeValue, "keyM" + ToString(i), "valueM");
mem->Add(++seq, kTypeDeletion, "keyX" + ToString(i), "");
elem.push_back(mem);
}
cf_ids.push_back(cf_id++);
}
std::vector<autovector<MemTable*>> flush_candidates(num_cfs);
// Nothing to flush
for (int i = 0; i != num_cfs; ++i) {
auto list = lists[i];
ASSERT_FALSE(list->IsFlushPending());
ASSERT_FALSE(list->imm_flush_needed.load(std::memory_order_acquire));
list->PickMemtablesToFlush(nullptr /* memtable_id */, &flush_candidates[i]);
ASSERT_EQ(0, static_cast<int>(flush_candidates[i].size()));
}
// Request flush even though there is nothing to flush
for (int i = 0; i != num_cfs; ++i) {
auto list = lists[i];
list->FlushRequested();
ASSERT_FALSE(list->IsFlushPending());
ASSERT_FALSE(list->imm_flush_needed.load(std::memory_order_acquire));
}
// Add tables to column families
for (int i = 0; i != num_cfs; ++i) {
for (int j = 0; j != num_tables_per_cf; ++j) {
lists[i]->Add(tables[i][j], &to_delete);
}
ASSERT_EQ(num_tables_per_cf, lists[i]->NumNotFlushed());
ASSERT_TRUE(lists[i]->IsFlushPending());
ASSERT_TRUE(lists[i]->imm_flush_needed.load(std::memory_order_acquire));
}
autovector<const autovector<MemTable*>*> to_flush;
std::vector<uint64_t> prev_memtable_ids;
// For each column family, determine the memtables to flush
for (int k = 0; k != 4; ++k) {
std::vector<uint64_t> flush_memtable_ids;
if (0 == k) {
// +----+
// list[0]: |0 1| 2 3 4
// list[1]: |0 1| 2 3 4
// | +--+
// list[2]: |0| 1 2 3 4
// +-+
flush_memtable_ids = {1, 1, 0};
} else if (1 == k) {
// +----+ +---+
// list[0]: |0 1| |2 3| 4
// list[1]: |0 1| |2 3| 4
// | +--+ +---+
// list[2]: |0| 1 2 3 4
// +-+
flush_memtable_ids = {3, 3, 0};
} else if (2 == k) {
// +-----+ +---+
// list[0]: |0 1| |2 3| 4
// list[1]: |0 1| |2 3| 4
// | +---+ +---+
// | | +-------+
// list[2]: |0| |1 2 3| 4
// +-+ +-------+
flush_memtable_ids = {3, 3, 3};
} else {
// +-----+ +---+ +-+
// list[0]: |0 1| |2 3| |4|
// list[1]: |0 1| |2 3| |4|
// | +---+ +---+ | |
// | | +-------+ | |
// list[2]: |0| |1 2 3| |4|
// +-+ +-------+ +-+
flush_memtable_ids = {4, 4, 4};
}
assert(num_cfs == static_cast<int>(flush_memtable_ids.size()));
// Pick memtables to flush
for (int i = 0; i != num_cfs; ++i) {
flush_candidates[i].clear();
lists[i]->PickMemtablesToFlush(&flush_memtable_ids[i],
&flush_candidates[i]);
for (auto mem : flush_candidates[i]) {
mem->TEST_AtomicFlushSequenceNumber() = SequenceNumber(k);
}
if (prev_memtable_ids.empty()) {
ASSERT_EQ(flush_memtable_ids[i] - 0 + 1, flush_candidates[i].size());
} else {
ASSERT_EQ(flush_memtable_ids[i] - prev_memtable_ids[i],
flush_candidates[i].size());
}
ASSERT_EQ(num_tables_per_cf, lists[i]->NumNotFlushed());
ASSERT_FALSE(lists[i]->HasFlushRequested());
if (flush_memtable_ids[i] == num_tables_per_cf - 1) {
ASSERT_FALSE(
lists[i]->imm_flush_needed.load(std::memory_order_acquire));
} else {
ASSERT_TRUE(lists[i]->imm_flush_needed.load(std::memory_order_acquire));
}
}
prev_memtable_ids = flush_memtable_ids;
if (k < 3) {
for (const auto& mems : flush_candidates) {
uint64_t file_num = file_number.fetch_add(1);
for (auto m : mems) {
m->TEST_SetFlushCompleted(true);
m->TEST_SetFileNumber(file_num);
}
}
}
if (k == 0) {
// Rollback first pick of tables
for (int i = 0; i != num_cfs; ++i) {
auto list = lists[i];
const auto& mems = flush_candidates[i];
for (auto m : mems) {
m->TEST_SetFileNumber(0);
}
list->RollbackMemtableFlush(flush_candidates[i], 0);
ASSERT_TRUE(list->IsFlushPending());
ASSERT_TRUE(list->imm_flush_needed.load(std::memory_order_acquire));
}
prev_memtable_ids.clear();
}
if (k == 3) {
for (int i = 0; i != num_cfs; ++i) {
to_flush.emplace_back(&flush_candidates[i]);
}
}
}
s = Mock_InstallMemtableFlushResults(lists, cf_ids, mutable_cf_options_list,
to_flush, &to_delete);
ASSERT_OK(s);
to_delete.clear();
for (auto list : lists) {
list->current()->Unref(&to_delete);
delete list;
}
for (auto& mutable_cf_options : mutable_cf_options_list) {
if (mutable_cf_options != nullptr) {
delete mutable_cf_options;
mutable_cf_options = nullptr;
}
}
// All memtables in tables array must have been flushed, thus ready to be
// deleted.
ASSERT_EQ(to_delete.size(), tables.size() * tables.front().size());
for (const auto& m : to_delete) {
// Refcount should be 0 after calling InstallMemtableFlushResults.
// Verify this by Ref'ing and then Unref'ing.
m->Ref();
ASSERT_EQ(m, m->Unref());
delete m;
}
to_delete.clear();
}
TEST_F(MemTableListTest, HasOlderAtomicFlush) {
const size_t num_cfs = 3;
const size_t num_memtables_per_cf = 2;
SequenceNumber seq = 1;
Status s;
auto factory = std::make_shared<SkipListFactory>();
options.memtable_factory = factory;
ImmutableCFOptions ioptions(options);
InternalKeyComparator cmp(BytewiseComparator());
WriteBufferManager wb(options.db_write_buffer_size);
autovector<MemTable*> to_delete;
// Create MemTableLists
int min_write_buffer_number_to_merge = 3;
int max_write_buffer_number_to_maintain = 7;
autovector<MemTableList*> lists;
for (size_t i = 0; i != num_cfs; ++i) {
lists.emplace_back(new MemTableList(min_write_buffer_number_to_merge,
max_write_buffer_number_to_maintain));
}
autovector<uint32_t> cf_ids;
std::vector<std::vector<MemTable*>> tables;
autovector<const MutableCFOptions*> mutable_cf_options_list;
uint32_t cf_id = 0;
for (size_t k = 0; k != num_cfs; ++k) {
std::vector<MemTable*> elem;
mutable_cf_options_list.emplace_back(new MutableCFOptions(options));
uint64_t memtable_id = 0;
for (int i = 0; i != num_memtables_per_cf; ++i) {
MemTable* mem =
new MemTable(cmp, ioptions, *(mutable_cf_options_list.back()), &wb,
kMaxSequenceNumber, cf_id);
mem->SetID(memtable_id++);
mem->Ref();
std::string value;
mem->Add(++seq, kTypeValue, "key1", ToString(i));
mem->Add(++seq, kTypeValue, "keyN" + ToString(i), "valueN");
mem->Add(++seq, kTypeValue, "keyX" + ToString(i), "value");
mem->Add(++seq, kTypeValue, "keyM" + ToString(i), "valueM");
mem->Add(++seq, kTypeDeletion, "keyX" + ToString(i), "");
elem.push_back(mem);
}
tables.emplace_back(elem);
cf_ids.push_back(cf_id++);
}
// Add tables to column families' immutable memtable lists
for (size_t i = 0; i != num_cfs; ++i) {
for (size_t j = 0; j != num_memtables_per_cf; ++j) {
lists[i]->Add(tables[i][j], &to_delete);
}
lists[i]->FlushRequested();
ASSERT_EQ(num_memtables_per_cf, lists[i]->NumNotFlushed());
ASSERT_TRUE(lists[i]->IsFlushPending());
ASSERT_TRUE(lists[i]->imm_flush_needed.load(std::memory_order_acquire));
}
std::vector<autovector<MemTable*>> flush_candidates(num_cfs);
for (size_t i = 0; i != num_cfs; ++i) {
lists[i]->PickMemtablesToFlush(nullptr, &flush_candidates[i]);
for (auto m : flush_candidates[i]) {
m->TEST_AtomicFlushSequenceNumber() = 123;
}
lists[i]->RollbackMemtableFlush(flush_candidates[i], 0);
}
uint64_t memtable_id = num_memtables_per_cf - 1;
autovector<MemTable*> other_flush_candidates;
lists[0]->PickMemtablesToFlush(&memtable_id, &other_flush_candidates);
for (auto m : other_flush_candidates) {
m->TEST_AtomicFlushSequenceNumber() = 124;
m->TEST_SetFlushCompleted(true);
m->TEST_SetFileNumber(1);
}
autovector<const autovector<MemTable*>*> to_flush;
to_flush.emplace_back(&other_flush_candidates);
bool has_older_unfinished_atomic_flush = false;
bool found_batch_to_commit = false;
SyncPoint::GetInstance()->SetCallBack(
"MemTableList::TryInstallMemtableFlushResults:"
"HasOlderUnfinishedAtomicFlush:0",
[&](void* /*arg*/) { has_older_unfinished_atomic_flush = true; });
SyncPoint::GetInstance()->SetCallBack(
"MemTableList::TryInstallMemtableFlushResults:FoundBatchToCommit:0",
[&](void* /*arg*/) { found_batch_to_commit = true; });
SyncPoint::GetInstance()->EnableProcessing();
s = Mock_InstallMemtableFlushResults(lists, cf_ids, mutable_cf_options_list,
to_flush, &to_delete);
ASSERT_OK(s);
ASSERT_TRUE(has_older_unfinished_atomic_flush);
ASSERT_FALSE(found_batch_to_commit);
SyncPoint::GetInstance()->ClearAllCallBacks();
ASSERT_TRUE(to_delete.empty());
for (auto list : lists) {
list->current()->Unref(&to_delete);
delete list;
}
lists.clear();
ASSERT_EQ(num_cfs * num_memtables_per_cf, to_delete.size());
for (auto m : to_delete) {
m->Ref();
ASSERT_EQ(m, m->Unref());
delete m;
}
to_delete.clear();
for (auto& opts : mutable_cf_options_list) {
delete opts;
opts = nullptr;
}
mutable_cf_options_list.clear();
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
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