rocksdb/db/db_secondary_test.cc
Yanqin Jin 9358178edc Support for single-primary, multi-secondary instances (#4899)
Summary:
This PR allows RocksDB to run in single-primary, multi-secondary process mode.
The writer is a regular RocksDB (e.g. an `DBImpl`) instance playing the role of a primary.
Multiple `DBImplSecondary` processes (secondaries) share the same set of SST files, MANIFEST, WAL files with the primary. Secondaries tail the MANIFEST of the primary and apply updates to their own in-memory state of the file system, e.g. `VersionStorageInfo`.

This PR has several components:
1. (Originally in #4745). Add a `PathNotFound` subcode to `IOError` to denote the failure when a secondary tries to open a file which has been deleted by the primary.

2. (Similar to #4602). Add `FragmentBufferedReader` to handle partially-read, trailing record at the end of a log from where future read can continue.

3. (Originally in #4710 and #4820). Add implementation of the secondary, i.e. `DBImplSecondary`.
3.1 Tail the primary's MANIFEST during recovery.
3.2 Tail the primary's MANIFEST during normal processing by calling `ReadAndApply`.
3.3 Tailing WAL will be in a future PR.

4. Add an example in 'examples/multi_processes_example.cc' to demonstrate the usage of secondary RocksDB instance in a multi-process setting. Instructions to run the example can be found at the beginning of the source code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4899

Differential Revision: D14510945

Pulled By: riversand963

fbshipit-source-id: 4ac1c5693e6012ad23f7b4b42d3c374fecbe8886
2019-03-26 16:45:31 -07:00

481 lines
16 KiB
C++

// 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).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "db/db_impl_secondary.h"
#include "db/db_test_util.h"
#include "port/stack_trace.h"
#include "util/fault_injection_test_env.h"
#include "util/sync_point.h"
namespace rocksdb {
#ifndef ROCKSDB_LITE
class DBSecondaryTest : public DBTestBase {
public:
DBSecondaryTest()
: DBTestBase("/db_secondary_test"),
secondary_path_(),
handles_secondary_(),
db_secondary_(nullptr) {
secondary_path_ =
test::PerThreadDBPath(env_, "/db_secondary_test_secondary");
}
~DBSecondaryTest() override {
CloseSecondary();
if (getenv("KEEP_DB") != nullptr) {
fprintf(stdout, "Secondary DB is still at %s\n", secondary_path_.c_str());
} else {
Options options;
options.env = env_;
EXPECT_OK(DestroyDB(secondary_path_, options));
}
}
protected:
Status ReopenAsSecondary(const Options& options) {
return DB::OpenAsSecondary(options, dbname_, secondary_path_, &db_);
}
void OpenSecondary(const Options& options);
void OpenSecondaryWithColumnFamilies(
const std::vector<std::string>& column_families, const Options& options);
void CloseSecondary() {
for (auto h : handles_secondary_) {
db_secondary_->DestroyColumnFamilyHandle(h);
}
handles_secondary_.clear();
delete db_secondary_;
db_secondary_ = nullptr;
}
DBImplSecondary* db_secondary_full() {
return static_cast<DBImplSecondary*>(db_secondary_);
}
void CheckFileTypeCounts(const std::string& dir, int expected_log,
int expected_sst, int expected_manifest) const;
std::string secondary_path_;
std::vector<ColumnFamilyHandle*> handles_secondary_;
DB* db_secondary_;
};
void DBSecondaryTest::OpenSecondary(const Options& options) {
Status s =
DB::OpenAsSecondary(options, dbname_, secondary_path_, &db_secondary_);
ASSERT_OK(s);
}
void DBSecondaryTest::OpenSecondaryWithColumnFamilies(
const std::vector<std::string>& column_families, const Options& options) {
std::vector<ColumnFamilyDescriptor> cf_descs;
cf_descs.emplace_back(kDefaultColumnFamilyName, options);
for (const auto& cf_name : column_families) {
cf_descs.emplace_back(cf_name, options);
}
Status s = DB::OpenAsSecondary(options, dbname_, secondary_path_, cf_descs,
&handles_secondary_, &db_secondary_);
ASSERT_OK(s);
}
void DBSecondaryTest::CheckFileTypeCounts(const std::string& dir,
int expected_log, int expected_sst,
int expected_manifest) const {
std::vector<std::string> filenames;
env_->GetChildren(dir, &filenames);
int log_cnt = 0, sst_cnt = 0, manifest_cnt = 0;
for (auto file : filenames) {
uint64_t number;
FileType type;
if (ParseFileName(file, &number, &type)) {
log_cnt += (type == kLogFile);
sst_cnt += (type == kTableFile);
manifest_cnt += (type == kDescriptorFile);
}
}
ASSERT_EQ(expected_log, log_cnt);
ASSERT_EQ(expected_sst, sst_cnt);
ASSERT_EQ(expected_manifest, manifest_cnt);
}
TEST_F(DBSecondaryTest, ReopenAsSecondary) {
Options options;
options.env = env_;
Reopen(options);
ASSERT_OK(Put("foo", "foo_value"));
ASSERT_OK(Put("bar", "bar_value"));
ASSERT_OK(dbfull()->Flush(FlushOptions()));
Close();
ASSERT_OK(ReopenAsSecondary(options));
ASSERT_EQ("foo_value", Get("foo"));
ASSERT_EQ("bar_value", Get("bar"));
ReadOptions ropts;
ropts.verify_checksums = true;
auto db1 = static_cast<DBImplSecondary*>(db_);
ASSERT_NE(nullptr, db1);
Iterator* iter = db1->NewIterator(ropts);
ASSERT_NE(nullptr, iter);
size_t count = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
if (0 == count) {
ASSERT_EQ("bar", iter->key().ToString());
ASSERT_EQ("bar_value", iter->value().ToString());
} else if (1 == count) {
ASSERT_EQ("foo", iter->key().ToString());
ASSERT_EQ("foo_value", iter->value().ToString());
}
++count;
}
delete iter;
ASSERT_EQ(2, count);
}
TEST_F(DBSecondaryTest, OpenAsSecondary) {
Options options;
options.env = env_;
options.level0_file_num_compaction_trigger = 4;
Reopen(options);
for (int i = 0; i < 3; ++i) {
ASSERT_OK(Put("foo", "foo_value" + std::to_string(i)));
ASSERT_OK(Put("bar", "bar_value" + std::to_string(i)));
ASSERT_OK(Flush());
}
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr));
ASSERT_OK(dbfull()->TEST_WaitForCompact());
ReadOptions ropts;
ropts.verify_checksums = true;
const auto verify_db_func = [&](const std::string& foo_val,
const std::string& bar_val) {
std::string value;
ASSERT_OK(db_secondary_->Get(ropts, "foo", &value));
ASSERT_EQ(foo_val, value);
ASSERT_OK(db_secondary_->Get(ropts, "bar", &value));
ASSERT_EQ(bar_val, value);
Iterator* iter = db_secondary_->NewIterator(ropts);
ASSERT_NE(nullptr, iter);
iter->Seek("foo");
ASSERT_TRUE(iter->Valid());
ASSERT_EQ("foo", iter->key().ToString());
ASSERT_EQ(foo_val, iter->value().ToString());
iter->Seek("bar");
ASSERT_TRUE(iter->Valid());
ASSERT_EQ("bar", iter->key().ToString());
ASSERT_EQ(bar_val, iter->value().ToString());
size_t count = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
++count;
}
ASSERT_EQ(2, count);
delete iter;
};
verify_db_func("foo_value2", "bar_value2");
ASSERT_OK(Put("foo", "new_foo_value"));
ASSERT_OK(Put("bar", "new_bar_value"));
ASSERT_OK(Flush());
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
verify_db_func("new_foo_value", "new_bar_value");
}
TEST_F(DBSecondaryTest, OpenWithNonExistColumnFamily) {
Options options;
options.env = env_;
CreateAndReopenWithCF({"pikachu"}, options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
std::vector<ColumnFamilyDescriptor> cf_descs;
cf_descs.emplace_back(kDefaultColumnFamilyName, options1);
cf_descs.emplace_back("pikachu", options1);
cf_descs.emplace_back("eevee", options1);
Status s = DB::OpenAsSecondary(options1, dbname_, secondary_path_, cf_descs,
&handles_secondary_, &db_secondary_);
ASSERT_NOK(s);
}
TEST_F(DBSecondaryTest, OpenWithSubsetOfColumnFamilies) {
Options options;
options.env = env_;
CreateAndReopenWithCF({"pikachu"}, options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
ASSERT_EQ(0, handles_secondary_.size());
ASSERT_NE(nullptr, db_secondary_);
ASSERT_OK(Put(0 /*cf*/, "foo", "foo_value"));
ASSERT_OK(Put(1 /*cf*/, "foo", "foo_value"));
ASSERT_OK(Flush(0 /*cf*/));
ASSERT_OK(Flush(1 /*cf*/));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
ReadOptions ropts;
ropts.verify_checksums = true;
std::string value;
ASSERT_OK(db_secondary_->Get(ropts, "foo", &value));
ASSERT_EQ("foo_value", value);
}
TEST_F(DBSecondaryTest, SwitchToNewManifestDuringOpen) {
Options options;
options.env = env_;
Reopen(options);
Close();
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
SyncPoint::GetInstance()->LoadDependency(
{{"ReactiveVersionSet::MaybeSwitchManifest:AfterGetCurrentManifestPath:0",
"VersionSet::ProcessManifestWrites:BeforeNewManifest"},
{"VersionSet::ProcessManifestWrites:AfterNewManifest",
"ReactiveVersionSet::MaybeSwitchManifest:AfterGetCurrentManifestPath:"
"1"}});
SyncPoint::GetInstance()->EnableProcessing();
// Make sure db calls RecoverLogFiles so as to trigger a manifest write,
// which causes the db to switch to a new MANIFEST upon start.
port::Thread ro_db_thread([&]() {
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
CloseSecondary();
});
Reopen(options);
ro_db_thread.join();
}
TEST_F(DBSecondaryTest, MissingTableFileDuringOpen) {
Options options;
options.env = env_;
options.level0_file_num_compaction_trigger = 4;
Reopen(options);
for (int i = 0; i != options.level0_file_num_compaction_trigger; ++i) {
ASSERT_OK(Put("foo", "foo_value" + std::to_string(i)));
ASSERT_OK(Put("bar", "bar_value" + std::to_string(i)));
ASSERT_OK(dbfull()->Flush(FlushOptions()));
}
ASSERT_OK(dbfull()->TEST_WaitForFlushMemTable());
ASSERT_OK(dbfull()->TEST_WaitForCompact());
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
ReadOptions ropts;
ropts.verify_checksums = true;
std::string value;
ASSERT_OK(db_secondary_->Get(ropts, "foo", &value));
ASSERT_EQ("foo_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
value);
ASSERT_OK(db_secondary_->Get(ropts, "bar", &value));
ASSERT_EQ("bar_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
value);
Iterator* iter = db_secondary_->NewIterator(ropts);
ASSERT_NE(nullptr, iter);
iter->Seek("bar");
ASSERT_TRUE(iter->Valid());
ASSERT_EQ("bar", iter->key().ToString());
ASSERT_EQ("bar_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
iter->value().ToString());
iter->Seek("foo");
ASSERT_TRUE(iter->Valid());
ASSERT_EQ("foo", iter->key().ToString());
ASSERT_EQ("foo_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
iter->value().ToString());
size_t count = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
++count;
}
ASSERT_EQ(2, count);
delete iter;
}
TEST_F(DBSecondaryTest, MissingTableFile) {
int table_files_not_exist = 0;
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
SyncPoint::GetInstance()->SetCallBack(
"ReactiveVersionSet::ReadAndApply:AfterLoadTableHandlers",
[&](void* arg) {
Status s = *reinterpret_cast<Status*>(arg);
if (s.IsPathNotFound()) {
++table_files_not_exist;
} else if (!s.ok()) {
assert(false); // Should not reach here
}
});
SyncPoint::GetInstance()->EnableProcessing();
Options options;
options.env = env_;
options.level0_file_num_compaction_trigger = 4;
Reopen(options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
for (int i = 0; i != options.level0_file_num_compaction_trigger; ++i) {
ASSERT_OK(Put("foo", "foo_value" + std::to_string(i)));
ASSERT_OK(Put("bar", "bar_value" + std::to_string(i)));
ASSERT_OK(dbfull()->Flush(FlushOptions()));
}
ASSERT_OK(dbfull()->TEST_WaitForFlushMemTable());
ASSERT_OK(dbfull()->TEST_WaitForCompact());
ASSERT_NE(nullptr, db_secondary_full());
ReadOptions ropts;
ropts.verify_checksums = true;
std::string value;
ASSERT_NOK(db_secondary_->Get(ropts, "foo", &value));
ASSERT_NOK(db_secondary_->Get(ropts, "bar", &value));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
ASSERT_EQ(options.level0_file_num_compaction_trigger, table_files_not_exist);
ASSERT_OK(db_secondary_->Get(ropts, "foo", &value));
ASSERT_EQ("foo_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
value);
ASSERT_OK(db_secondary_->Get(ropts, "bar", &value));
ASSERT_EQ("bar_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
value);
Iterator* iter = db_secondary_->NewIterator(ropts);
ASSERT_NE(nullptr, iter);
iter->Seek("bar");
ASSERT_TRUE(iter->Valid());
ASSERT_EQ("bar", iter->key().ToString());
ASSERT_EQ("bar_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
iter->value().ToString());
iter->Seek("foo");
ASSERT_TRUE(iter->Valid());
ASSERT_EQ("foo", iter->key().ToString());
ASSERT_EQ("foo_value" +
std::to_string(options.level0_file_num_compaction_trigger - 1),
iter->value().ToString());
size_t count = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
++count;
}
ASSERT_EQ(2, count);
delete iter;
}
TEST_F(DBSecondaryTest, PrimaryDropColumnFamily) {
Options options;
options.env = env_;
const std::string kCfName1 = "pikachu";
CreateAndReopenWithCF({kCfName1}, options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondaryWithColumnFamilies({kCfName1}, options1);
ASSERT_EQ(2, handles_secondary_.size());
ASSERT_OK(Put(1 /*cf*/, "foo", "foo_val_1"));
ASSERT_OK(Flush(1 /*cf*/));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
ReadOptions ropts;
ropts.verify_checksums = true;
std::string value;
ASSERT_OK(db_secondary_->Get(ropts, handles_secondary_[1], "foo", &value));
ASSERT_EQ("foo_val_1", value);
ASSERT_OK(dbfull()->DropColumnFamily(handles_[1]));
Close();
CheckFileTypeCounts(dbname_, 1, 0, 1);
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
value.clear();
ASSERT_OK(db_secondary_->Get(ropts, handles_secondary_[1], "foo", &value));
ASSERT_EQ("foo_val_1", value);
}
TEST_F(DBSecondaryTest, SwitchManifest) {
Options options;
options.env = env_;
options.level0_file_num_compaction_trigger = 4;
Reopen(options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
const int kNumFiles = options.level0_file_num_compaction_trigger - 1;
// Keep it smaller than 10 so that key0, key1, ..., key9 are sorted as 0, 1,
// ..., 9.
const int kNumKeys = 10;
// Create two sst
for (int i = 0; i != kNumFiles; ++i) {
for (int j = 0; j != kNumKeys; ++j) {
ASSERT_OK(Put("key" + std::to_string(j), "value_" + std::to_string(i)));
}
ASSERT_OK(Flush());
}
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
const auto& range_scan_db = [&]() {
ReadOptions tmp_ropts;
tmp_ropts.total_order_seek = true;
tmp_ropts.verify_checksums = true;
std::unique_ptr<Iterator> iter(db_secondary_->NewIterator(tmp_ropts));
int cnt = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next(), ++cnt) {
ASSERT_EQ("key" + std::to_string(cnt), iter->key().ToString());
ASSERT_EQ("value_" + std::to_string(kNumFiles - 1),
iter->value().ToString());
}
};
range_scan_db();
// While secondary instance still keeps old MANIFEST open, we close primary,
// restart primary, performs full compaction, close again, restart again so
// that next time secondary tries to catch up with primary, the secondary
// will skip the MANIFEST in middle.
Reopen(options);
ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr));
ASSERT_OK(dbfull()->TEST_WaitForCompact());
Reopen(options);
ASSERT_OK(dbfull()->SetOptions({{"disable_auto_compactions", "false"}}));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
range_scan_db();
}
#endif //! ROCKSDB_LITE
} // namespace rocksdb
int main(int argc, char** argv) {
rocksdb::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}