rocksdb/db/db_impl/db_secondary_test.cc

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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 23:41:31 +00:00
// 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/db_impl_secondary.h"
#include "db/db_test_util.h"
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 23:41:31 +00:00
#include "port/stack_trace.h"
#include "test_util/fault_injection_test_env.h"
#include "test_util/sync_point.h"
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 23:41:31 +00:00
namespace ROCKSDB_NAMESPACE {
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 23:41:31 +00:00
#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");
}
namespace {
class TraceFileEnv : public EnvWrapper {
public:
explicit TraceFileEnv(Env* _target) : EnvWrapper(_target) {}
Status NewRandomAccessFile(const std::string& f,
std::unique_ptr<RandomAccessFile>* r,
const EnvOptions& env_options) override {
class TracedRandomAccessFile : public RandomAccessFile {
public:
TracedRandomAccessFile(std::unique_ptr<RandomAccessFile>&& target,
std::atomic<int>& counter)
: target_(std::move(target)), files_closed_(counter) {}
~TracedRandomAccessFile() override {
files_closed_.fetch_add(1, std::memory_order_relaxed);
}
Status Read(uint64_t offset, size_t n, Slice* result,
char* scratch) const override {
return target_->Read(offset, n, result, scratch);
}
private:
std::unique_ptr<RandomAccessFile> target_;
std::atomic<int>& files_closed_;
};
Status s = target()->NewRandomAccessFile(f, r, env_options);
if (s.ok()) {
r->reset(new TracedRandomAccessFile(std::move(*r), files_closed_));
}
return s;
}
int files_closed() const {
return files_closed_.load(std::memory_order_relaxed);
}
private:
std::atomic<int> files_closed_{0};
};
} // namespace
TEST_F(DBSecondaryTest, SecondaryCloseFiles) {
Options options;
options.env = env_;
options.max_open_files = 1;
options.disable_auto_compactions = true;
Reopen(options);
Options options1;
std::unique_ptr<Env> traced_env(new TraceFileEnv(env_));
options1.env = traced_env.get();
OpenSecondary(options1);
static const auto verify_db = [&]() {
std::unique_ptr<Iterator> iter1(dbfull()->NewIterator(ReadOptions()));
std::unique_ptr<Iterator> iter2(db_secondary_->NewIterator(ReadOptions()));
for (iter1->SeekToFirst(), iter2->SeekToFirst();
iter1->Valid() && iter2->Valid(); iter1->Next(), iter2->Next()) {
ASSERT_EQ(iter1->key(), iter2->key());
ASSERT_EQ(iter1->value(), iter2->value());
}
ASSERT_FALSE(iter1->Valid());
ASSERT_FALSE(iter2->Valid());
};
ASSERT_OK(Put("a", "value"));
ASSERT_OK(Put("c", "value"));
ASSERT_OK(Flush());
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
verify_db();
ASSERT_OK(Put("b", "value"));
ASSERT_OK(Put("d", "value"));
ASSERT_OK(Flush());
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
verify_db();
ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
ASSERT_EQ(2, static_cast<TraceFileEnv*>(traced_env.get())->files_closed());
Status s = db_secondary_->SetDBOptions({{"max_open_files", "-1"}});
ASSERT_TRUE(s.IsNotSupported());
CloseSecondary();
}
TEST_F(DBSecondaryTest, OpenAsSecondaryWALTailing) {
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)));
}
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
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(db_secondary_->TryCatchUpWithPrimary());
verify_db_func("new_foo_value", "new_bar_value");
ASSERT_OK(Flush());
ASSERT_OK(Put("foo", "new_foo_value_1"));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
verify_db_func("new_foo_value_1", "new_bar_value");
}
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 23:41:31 +00:00
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::ApplyOneVersionEditToBuilder:AfterLoadTableHandlers",
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 23:41:31 +00:00
[&](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();
}
// Here, "Snapshot" refers to the version edits written by
// VersionSet::WriteSnapshot() at the beginning of the new MANIFEST after
// switching from the old one.
TEST_F(DBSecondaryTest, SkipSnapshotAfterManifestSwitch) {
Options options;
options.env = env_;
options.disable_auto_compactions = true;
Reopen(options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
ASSERT_OK(Put("0", "value0"));
ASSERT_OK(Flush());
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
std::string value;
ReadOptions ropts;
ropts.verify_checksums = true;
ASSERT_OK(db_secondary_->Get(ropts, "0", &value));
ASSERT_EQ("value0", value);
Reopen(options);
ASSERT_OK(dbfull()->SetOptions({{"disable_auto_compactions", "false"}}));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
}
TEST_F(DBSecondaryTest, SwitchWAL) {
const int kNumKeysPerMemtable = 1;
Options options;
options.env = env_;
options.max_write_buffer_number = 4;
options.min_write_buffer_number_to_merge = 2;
options.memtable_factory.reset(
new SpecialSkipListFactory(kNumKeysPerMemtable));
Reopen(options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
const auto& verify_db = [](DB* db1, DB* db2) {
ASSERT_NE(nullptr, db1);
ASSERT_NE(nullptr, db2);
ReadOptions read_opts;
read_opts.verify_checksums = true;
std::unique_ptr<Iterator> it1(db1->NewIterator(read_opts));
std::unique_ptr<Iterator> it2(db2->NewIterator(read_opts));
it1->SeekToFirst();
it2->SeekToFirst();
for (; it1->Valid() && it2->Valid(); it1->Next(), it2->Next()) {
ASSERT_EQ(it1->key(), it2->key());
ASSERT_EQ(it1->value(), it2->value());
}
ASSERT_FALSE(it1->Valid());
ASSERT_FALSE(it2->Valid());
for (it1->SeekToFirst(); it1->Valid(); it1->Next()) {
std::string value;
ASSERT_OK(db2->Get(read_opts, it1->key(), &value));
ASSERT_EQ(it1->value(), value);
}
for (it2->SeekToFirst(); it2->Valid(); it2->Next()) {
std::string value;
ASSERT_OK(db1->Get(read_opts, it2->key(), &value));
ASSERT_EQ(it2->value(), value);
}
};
for (int k = 0; k != 16; ++k) {
ASSERT_OK(Put("key" + std::to_string(k), "value" + std::to_string(k)));
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
verify_db(dbfull(), db_secondary_);
}
}
TEST_F(DBSecondaryTest, SwitchWALMultiColumnFamilies) {
const int kNumKeysPerMemtable = 1;
Improve memtable earliest seqno assignment for secondary instance (#5413) Summary: In regular RocksDB instance, `MemTable::earliest_seqno_` is "db sequence number at the time of creation". However, we cannot use the db sequence number to set the value of `MemTable::earliest_seqno_` for secondary instance, i.e. `DBImplSecondary` due to the logic of MANIFEST and WAL replay. When replaying the log files of the primary, the secondary instance first replays MANIFEST and updates the db sequence number if necessary. Next, the secondary replays WAL files, creates new memtables if necessary and inserts key-value pairs into memtables. The following can occur when the db has two or more column families. Assume the db has column family "default" and "cf1". At a certain in time, both "default" and "cf1" have data in memtables. 1. Primary triggers a flush and flushes "cf1". "default" is **not** flushed. 2. Secondary replays the MANIFEST updates its db sequence number to the latest value learned from the MANIFEST. 3. Secondary starts to replay WAL that contains the writes to "default". It is possible that the write batches' sequence numbers are smaller than the db sequence number. In this case, these write batches will be skipped, and these updates will not be visible to reader until "default" is later flushed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5413 Differential Revision: D15637407 Pulled By: riversand963 fbshipit-source-id: 3de3fe35cfc6f1b9f844f3f926f0df29717b6580
2019-06-10 19:53:56 +00:00
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->LoadDependency(
{{"DBImpl::BackgroundCallFlush:ContextCleanedUp",
"DBSecondaryTest::SwitchWALMultipleColumnFamilies:BeforeCatchUp"}});
Improve memtable earliest seqno assignment for secondary instance (#5413) Summary: In regular RocksDB instance, `MemTable::earliest_seqno_` is "db sequence number at the time of creation". However, we cannot use the db sequence number to set the value of `MemTable::earliest_seqno_` for secondary instance, i.e. `DBImplSecondary` due to the logic of MANIFEST and WAL replay. When replaying the log files of the primary, the secondary instance first replays MANIFEST and updates the db sequence number if necessary. Next, the secondary replays WAL files, creates new memtables if necessary and inserts key-value pairs into memtables. The following can occur when the db has two or more column families. Assume the db has column family "default" and "cf1". At a certain in time, both "default" and "cf1" have data in memtables. 1. Primary triggers a flush and flushes "cf1". "default" is **not** flushed. 2. Secondary replays the MANIFEST updates its db sequence number to the latest value learned from the MANIFEST. 3. Secondary starts to replay WAL that contains the writes to "default". It is possible that the write batches' sequence numbers are smaller than the db sequence number. In this case, these write batches will be skipped, and these updates will not be visible to reader until "default" is later flushed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5413 Differential Revision: D15637407 Pulled By: riversand963 fbshipit-source-id: 3de3fe35cfc6f1b9f844f3f926f0df29717b6580
2019-06-10 19:53:56 +00:00
SyncPoint::GetInstance()->EnableProcessing();
const std::string kCFName1 = "pikachu";
Options options;
options.env = env_;
options.max_write_buffer_number = 4;
options.min_write_buffer_number_to_merge = 2;
options.memtable_factory.reset(
new SpecialSkipListFactory(kNumKeysPerMemtable));
CreateAndReopenWithCF({kCFName1}, options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondaryWithColumnFamilies({kCFName1}, options1);
ASSERT_EQ(2, handles_secondary_.size());
const auto& verify_db = [](DB* db1,
const std::vector<ColumnFamilyHandle*>& handles1,
DB* db2,
const std::vector<ColumnFamilyHandle*>& handles2) {
ASSERT_NE(nullptr, db1);
ASSERT_NE(nullptr, db2);
ReadOptions read_opts;
read_opts.verify_checksums = true;
ASSERT_EQ(handles1.size(), handles2.size());
for (size_t i = 0; i != handles1.size(); ++i) {
std::unique_ptr<Iterator> it1(db1->NewIterator(read_opts, handles1[i]));
std::unique_ptr<Iterator> it2(db2->NewIterator(read_opts, handles2[i]));
it1->SeekToFirst();
it2->SeekToFirst();
for (; it1->Valid() && it2->Valid(); it1->Next(), it2->Next()) {
ASSERT_EQ(it1->key(), it2->key());
ASSERT_EQ(it1->value(), it2->value());
}
ASSERT_FALSE(it1->Valid());
ASSERT_FALSE(it2->Valid());
for (it1->SeekToFirst(); it1->Valid(); it1->Next()) {
std::string value;
ASSERT_OK(db2->Get(read_opts, handles2[i], it1->key(), &value));
ASSERT_EQ(it1->value(), value);
}
for (it2->SeekToFirst(); it2->Valid(); it2->Next()) {
std::string value;
ASSERT_OK(db1->Get(read_opts, handles1[i], it2->key(), &value));
ASSERT_EQ(it2->value(), value);
}
}
};
for (int k = 0; k != 8; ++k) {
ASSERT_OK(
Put(0 /*cf*/, "key" + std::to_string(k), "value" + std::to_string(k)));
ASSERT_OK(
Put(1 /*cf*/, "key" + std::to_string(k), "value" + std::to_string(k)));
TEST_SYNC_POINT(
"DBSecondaryTest::SwitchWALMultipleColumnFamilies:BeforeCatchUp");
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
verify_db(dbfull(), handles_, db_secondary_, handles_secondary_);
Improve memtable earliest seqno assignment for secondary instance (#5413) Summary: In regular RocksDB instance, `MemTable::earliest_seqno_` is "db sequence number at the time of creation". However, we cannot use the db sequence number to set the value of `MemTable::earliest_seqno_` for secondary instance, i.e. `DBImplSecondary` due to the logic of MANIFEST and WAL replay. When replaying the log files of the primary, the secondary instance first replays MANIFEST and updates the db sequence number if necessary. Next, the secondary replays WAL files, creates new memtables if necessary and inserts key-value pairs into memtables. The following can occur when the db has two or more column families. Assume the db has column family "default" and "cf1". At a certain in time, both "default" and "cf1" have data in memtables. 1. Primary triggers a flush and flushes "cf1". "default" is **not** flushed. 2. Secondary replays the MANIFEST updates its db sequence number to the latest value learned from the MANIFEST. 3. Secondary starts to replay WAL that contains the writes to "default". It is possible that the write batches' sequence numbers are smaller than the db sequence number. In this case, these write batches will be skipped, and these updates will not be visible to reader until "default" is later flushed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5413 Differential Revision: D15637407 Pulled By: riversand963 fbshipit-source-id: 3de3fe35cfc6f1b9f844f3f926f0df29717b6580
2019-06-10 19:53:56 +00:00
SyncPoint::GetInstance()->ClearTrace();
}
}
TEST_F(DBSecondaryTest, CatchUpAfterFlush) {
const int kNumKeysPerMemtable = 16;
Options options;
options.env = env_;
options.max_write_buffer_number = 4;
options.min_write_buffer_number_to_merge = 2;
options.memtable_factory.reset(
new SpecialSkipListFactory(kNumKeysPerMemtable));
Reopen(options);
Options options1;
options1.env = env_;
options1.max_open_files = -1;
OpenSecondary(options1);
WriteOptions write_opts;
WriteBatch wb;
wb.Put("key0", "value0");
wb.Put("key1", "value1");
ASSERT_OK(dbfull()->Write(write_opts, &wb));
ReadOptions read_opts;
std::unique_ptr<Iterator> iter1(db_secondary_->NewIterator(read_opts));
iter1->Seek("key0");
ASSERT_FALSE(iter1->Valid());
iter1->Seek("key1");
ASSERT_FALSE(iter1->Valid());
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
iter1->Seek("key0");
ASSERT_FALSE(iter1->Valid());
iter1->Seek("key1");
ASSERT_FALSE(iter1->Valid());
std::unique_ptr<Iterator> iter2(db_secondary_->NewIterator(read_opts));
iter2->Seek("key0");
ASSERT_TRUE(iter2->Valid());
ASSERT_EQ("value0", iter2->value());
iter2->Seek("key1");
ASSERT_TRUE(iter2->Valid());
ASSERT_EQ("value1", iter2->value());
{
WriteBatch wb1;
wb1.Put("key0", "value01");
wb1.Put("key1", "value11");
ASSERT_OK(dbfull()->Write(write_opts, &wb1));
}
{
WriteBatch wb2;
wb2.Put("key0", "new_value0");
wb2.Delete("key1");
ASSERT_OK(dbfull()->Write(write_opts, &wb2));
}
ASSERT_OK(Flush());
ASSERT_OK(db_secondary_->TryCatchUpWithPrimary());
std::unique_ptr<Iterator> iter3(db_secondary_->NewIterator(read_opts));
// iter3 should not see value01 and value11 at all.
iter3->Seek("key0");
ASSERT_TRUE(iter3->Valid());
ASSERT_EQ("new_value0", iter3->value());
iter3->Seek("key1");
ASSERT_FALSE(iter3->Valid());
}
TEST_F(DBSecondaryTest, CheckConsistencyWhenOpen) {
bool called = false;
Options options;
options.env = env_;
options.disable_auto_compactions = true;
Reopen(options);
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
SyncPoint::GetInstance()->SetCallBack(
"DBImplSecondary::CheckConsistency:AfterFirstAttempt", [&](void* arg) {
ASSERT_NE(nullptr, arg);
called = true;
auto* s = reinterpret_cast<Status*>(arg);
ASSERT_NOK(*s);
});
SyncPoint::GetInstance()->LoadDependency(
{{"DBImpl::CheckConsistency:AfterGetLiveFilesMetaData",
"BackgroundCallCompaction:0"},
{"DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles",
"DBImpl::CheckConsistency:BeforeGetFileSize"}});
SyncPoint::GetInstance()->EnableProcessing();
ASSERT_OK(Put("a", "value0"));
ASSERT_OK(Put("c", "value0"));
ASSERT_OK(Flush());
ASSERT_OK(Put("b", "value1"));
ASSERT_OK(Put("d", "value1"));
ASSERT_OK(Flush());
port::Thread thread([this]() {
Options opts;
opts.env = env_;
opts.max_open_files = -1;
OpenSecondary(opts);
});
ASSERT_OK(dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr));
ASSERT_OK(dbfull()->TEST_WaitForCompact());
thread.join();
ASSERT_TRUE(called);
}
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 23:41:31 +00:00
#endif //! ROCKSDB_LITE
} // namespace ROCKSDB_NAMESPACE
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 23:41:31 +00:00
int main(int argc, char** argv) {
ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
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 23:41:31 +00:00
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}