src/kudu/tools/ksck-test.cc - kudu - Git at Google

 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
 // regarding copyright ownership.  The ASF licenses this file
 // to you under the Apache License, Version 2.0 (the
 // "License"); you may not use this file except in compliance
 // with the License.  You may obtain a copy of the License at
 //
 //   http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing,
 // software distributed under the License is distributed on an
 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License.

 #include <iosfwd>
 #include <memory>
 #include <unordered_map>

 #include <gflags/gflags.h>
 #include <gtest/gtest.h>

 #include "kudu/gutil/map-util.h"
 #include "kudu/gutil/strings/substitute.h"
 #include "kudu/tools/ksck.h"
 #include "kudu/util/scoped_cleanup.h"
 #include "kudu/util/test_util.h"

 DECLARE_string(color);

 namespace kudu {
 namespace tools {

 using std::shared_ptr;
 using std::static_pointer_cast;
 using std::string;
 using std::unordered_map;
 using strings::Substitute;

 // Import this symbol from ksck.cc so we can introspect the
 // errors being written to stderr.
 extern std::ostream* g_err_stream;

 class MockKsckTabletServer : public KsckTabletServer {
  public:
   explicit MockKsckTabletServer(const string& uuid)
       : KsckTabletServer(uuid),
         fetch_info_status_(Status::OK()),
         address_("<mock>") {
   }

   Status FetchInfo() override {
     timestamp_ = 12345;
     if (fetch_info_status_.ok()) {
       state_ = kFetched;
     } else {
       state_ = kFetchFailed;
     }
     return fetch_info_status_;
   }

   virtual void RunTabletChecksumScanAsync(
       const std::string& tablet_id,
       const Schema& schema,
       const ChecksumOptions& options,
       ChecksumProgressCallbacks* callbacks) OVERRIDE {
     callbacks->Progress(10, 20);
     callbacks->Finished(Status::OK(), 0);
   }

   virtual std::string address() const OVERRIDE {
     return address_;
   }

   // Public because the unit tests mutate this variable directly.
   Status fetch_info_status_;

  private:
   const string address_;
 };

 class MockKsckMaster : public KsckMaster {
  public:
   MockKsckMaster()
       : fetch_info_status_(Status::OK()) {
   }

   virtual Status Connect() OVERRIDE {
     return fetch_info_status_;
   }

   virtual Status RetrieveTabletServers(TSMap* tablet_servers) OVERRIDE {
     *tablet_servers = tablet_servers_;
     return Status::OK();
   }

   virtual Status RetrieveTablesList(vector<shared_ptr<KsckTable>>* tables) OVERRIDE {
     tables->assign(tables_.begin(), tables_.end());
     return Status::OK();
   }

   virtual Status RetrieveTabletsList(const shared_ptr<KsckTable>& table) OVERRIDE {
     return Status::OK();
   }

   // Public because the unit tests mutate these variables directly.
   Status fetch_info_status_;
   TSMap tablet_servers_;
   vector<shared_ptr<KsckTable>> tables_;
 };

 class KsckTest : public KuduTest {
  public:
   KsckTest()
       : master_(new MockKsckMaster()),
         cluster_(new KsckCluster(static_pointer_cast<KsckMaster>(master_))),
         ksck_(new Ksck(cluster_)) {
     FLAGS_color = "never";
     unordered_map<string, shared_ptr<KsckTabletServer>> tablet_servers;
     for (int i = 0; i < 3; i++) {
       string name = Substitute("ts-id-$0", i);
       shared_ptr<MockKsckTabletServer> ts(new MockKsckTabletServer(name));
       InsertOrDie(&tablet_servers, ts->uuid(), ts);
     }
     master_->tablet_servers_.swap(tablet_servers);

     g_err_stream = &err_stream_;
   }

   ~KsckTest() {
     g_err_stream = NULL;
   }

  protected:
   void CreateDefaultAssignmentPlan(int tablets_count) {
     while (tablets_count > 0) {
       for (const KsckMaster::TSMap::value_type& entry : master_->tablet_servers_) {
         if (tablets_count-- == 0) return;
         assignment_plan_.push_back(entry.second->uuid());
       }
     }
   }

   void CreateOneTableOneTablet() {
     CreateDefaultAssignmentPlan(1);

     auto table = CreateAndAddTable("test", 1);
     shared_ptr<KsckTablet> tablet(new KsckTablet(table.get(), "tablet-id-1"));
     CreateAndFillTablet(tablet, 1, true, true);
     table->set_tablets({ tablet });
   }

   void CreateOneSmallReplicatedTable() {
     int num_replicas = 3;
     int num_tablets = 3;
     CreateDefaultAssignmentPlan(num_replicas * num_tablets);
     auto table = CreateAndAddTable("test", num_replicas);

     vector<shared_ptr<KsckTablet>> tablets;
     for (int i = 0; i < num_tablets; i++) {
       shared_ptr<KsckTablet> tablet(new KsckTablet(
           table.get(), Substitute("tablet-id-$0", i)));
       CreateAndFillTablet(tablet, num_replicas, true, true);
       tablets.push_back(tablet);
     }
     table->set_tablets(tablets);
   }

   void CreateOneSmallReplicatedTableWithTabletNotRunning() {
     int num_replicas = 3;
     int num_tablets = 3;
     CreateDefaultAssignmentPlan(num_replicas * num_tablets);
     auto table = CreateAndAddTable("test", num_replicas);

     vector<shared_ptr<KsckTablet>> tablets;
     for (int i = 0; i < num_tablets; i++) {
       shared_ptr<KsckTablet> tablet(new KsckTablet(
           table.get(), Substitute("tablet-id-$0", i)));
       CreateAndFillTablet(tablet, num_replicas, true, i != 0);
       tablets.push_back(tablet);
     }
     table->set_tablets(tablets);
   }

   void CreateOneOneTabletReplicatedBrokenTable() {
     // We're placing only two tablets, the 3rd goes nowhere.
     CreateDefaultAssignmentPlan(2);

     auto table = CreateAndAddTable("test", 3);

     shared_ptr<KsckTablet> tablet(new KsckTablet(table.get(), "tablet-id-1"));
     CreateAndFillTablet(tablet, 2, false, true);
     table->set_tablets({ tablet });
   }

   shared_ptr<KsckTable> CreateAndAddTable(const string& name, int num_replicas) {
     shared_ptr<KsckTable> table(new KsckTable(name, Schema(), num_replicas));
     vector<shared_ptr<KsckTable>> tables = { table };
     master_->tables_.assign(tables.begin(), tables.end());
     return table;
   }

   void CreateAndFillTablet(shared_ptr<KsckTablet>& tablet, int num_replicas,
                            bool has_leader, bool is_running) {
     vector<shared_ptr<KsckTabletReplica>> replicas;
     if (has_leader) {
       CreateReplicaAndAdd(replicas, tablet->id(), true, is_running);
       num_replicas--;
     }
     for (int i = 0; i < num_replicas; i++) {
       CreateReplicaAndAdd(replicas, tablet->id(), false, is_running);
     }
     tablet->set_replicas(replicas);
   }

   void CreateReplicaAndAdd(vector<shared_ptr<KsckTabletReplica>>& replicas,
                            string tablet_id,
                            bool is_leader,
                            bool is_running) {
     shared_ptr<KsckTabletReplica> replica(new KsckTabletReplica(assignment_plan_.back(),
                                                                 is_leader));
     shared_ptr<MockKsckTabletServer> ts = static_pointer_cast<MockKsckTabletServer>(
             master_->tablet_servers_.at(assignment_plan_.back()));

     assignment_plan_.pop_back();
     replicas.push_back(replica);

     // Add the equivalent replica on the tablet server.
     tablet::TabletStatusPB pb;
     pb.set_tablet_id(tablet_id);
     pb.set_table_name("fake-table");
     pb.set_state(is_running ? tablet::RUNNING : tablet::FAILED);
     InsertOrDie(&ts->tablet_status_map_, tablet_id, std::move(pb));
   }

   Status RunKsck() {
     auto c = MakeScopedCleanup([this]() {
         LOG(INFO) << "Ksck output:\n" << err_stream_.str();
       });
     RETURN_NOT_OK(ksck_->CheckMasterRunning());
     RETURN_NOT_OK(ksck_->FetchTableAndTabletInfo());
     RETURN_NOT_OK(ksck_->FetchInfoFromTabletServers());
     RETURN_NOT_OK(ksck_->CheckTablesConsistency());
     return Status::OK();
   }


   shared_ptr<MockKsckMaster> master_;
   shared_ptr<KsckCluster> cluster_;
   shared_ptr<Ksck> ksck_;
   // This is used as a stack. First the unit test is responsible to create a plan to follow, that
   // is the order in which each replica of each tablet will be assigned, starting from the end.
   // So if you have 2 tablets with num_replicas=3 and 3 tablet servers, then to distribute evenly
   // you should have a list that looks like ts1,ts2,ts3,ts3,ts2,ts1 so that the two LEADERS, which
   // are assigned first, end up on ts1 and ts3.
   vector<string> assignment_plan_;

   std::ostringstream err_stream_;
 };

 TEST_F(KsckTest, TestMasterOk) {
   ASSERT_OK(ksck_->CheckMasterRunning());
 }

 TEST_F(KsckTest, TestMasterUnavailable) {
   Status error = Status::NetworkError("Network failure");
   master_->fetch_info_status_ = error;
   ASSERT_TRUE(ksck_->CheckMasterRunning().IsNetworkError());
 }

 TEST_F(KsckTest, TestTabletServersOk) {
   ASSERT_OK(RunKsck());
 }

 TEST_F(KsckTest, TestBadTabletServer) {
   CreateOneSmallReplicatedTable();

   // Mock a failure to connect to one of the tablet servers.
   Status error = Status::NetworkError("Network failure");
   static_pointer_cast<MockKsckTabletServer>(master_->tablet_servers_["ts-id-1"])
       ->fetch_info_status_ = error;

   ASSERT_OK(ksck_->CheckMasterRunning());
   ASSERT_OK(ksck_->FetchTableAndTabletInfo());
   Status s = ksck_->FetchInfoFromTabletServers();
   ASSERT_TRUE(s.IsNetworkError()) << "Status returned: " << s.ToString();

   s = ksck_->CheckTablesConsistency();
   EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
   ASSERT_STR_CONTAINS(
       err_stream_.str(),
       "WARNING: Unable to connect to Tablet Server "
       "ts-id-1 (<mock>): Network error: Network failure");
   ASSERT_STR_CONTAINS(
       err_stream_.str(),
       "Tablet tablet-id-0 of table 'test' is under-replicated: 1 replica(s) not RUNNING\n"
       "  ts-id-0 (<mock>): RUNNING [LEADER]\n"
       "  ts-id-1 (<mock>): TS unavailable\n"
       "  ts-id-2 (<mock>): RUNNING\n");
   ASSERT_STR_CONTAINS(
       err_stream_.str(),
       "Tablet tablet-id-1 of table 'test' is under-replicated: 1 replica(s) not RUNNING\n"
       "  ts-id-0 (<mock>): RUNNING [LEADER]\n"
       "  ts-id-1 (<mock>): TS unavailable\n"
       "  ts-id-2 (<mock>): RUNNING\n");
   ASSERT_STR_CONTAINS(
       err_stream_.str(),
       "Tablet tablet-id-2 of table 'test' is under-replicated: 1 replica(s) not RUNNING\n"
       "  ts-id-0 (<mock>): RUNNING [LEADER]\n"
       "  ts-id-1 (<mock>): TS unavailable\n"
       "  ts-id-2 (<mock>): RUNNING\n");
 }

 TEST_F(KsckTest, TestZeroTabletReplicasCheck) {
   ASSERT_OK(RunKsck());
 }

 TEST_F(KsckTest, TestZeroTableCheck) {
   ASSERT_OK(RunKsck());
 }

 TEST_F(KsckTest, TestOneTableCheck) {
   CreateOneTableOneTablet();
   ASSERT_OK(RunKsck());
   ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "0/1 replicas remaining (20B from disk, 10 rows summed)");
 }

 TEST_F(KsckTest, TestOneSmallReplicatedTable) {
   CreateOneSmallReplicatedTable();
   ASSERT_OK(RunKsck());
   ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "0/9 replicas remaining (180B from disk, 90 rows summed)");

   // Test filtering (a non-matching pattern)
   err_stream_.str("");
   ksck_->set_table_filters({"xyz"});
   ASSERT_OK(RunKsck());
   Status s = ksck_->ChecksumData(ChecksumOptions());
   EXPECT_EQ("Not found: No table found. Filter: table_filters=xyz", s.ToString());
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "The cluster doesn't have any matching tables");

   // Test filtering with a matching table pattern.
   err_stream_.str("");
   ksck_->set_table_filters({"te*"});
   ASSERT_OK(RunKsck());
   ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "0/9 replicas remaining (180B from disk, 90 rows summed)");

   // Test filtering with a matching tablet ID pattern.
   err_stream_.str("");
   ksck_->set_table_filters({});
   ksck_->set_tablet_id_filters({"*-id-2"});
   ASSERT_OK(RunKsck());
   ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "0/3 replicas remaining (60B from disk, 30 rows summed)");
 }

 TEST_F(KsckTest, TestOneOneTabletBrokenTable) {
   CreateOneOneTabletReplicatedBrokenTable();
   Status s = RunKsck();
   EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "Tablet tablet-id-1 of table 'test' is under-replicated: "
                       "configuration has 2 replicas vs desired 3");
 }

 TEST_F(KsckTest, TestMismatchedAssignments) {
   CreateOneSmallReplicatedTable();
   shared_ptr<MockKsckTabletServer> ts = static_pointer_cast<MockKsckTabletServer>(
       master_->tablet_servers_.at(Substitute("ts-id-$0", 0)));
   ASSERT_EQ(1, ts->tablet_status_map_.erase("tablet-id-2"));

   Status s = RunKsck();
   EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
   ASSERT_STR_CONTAINS(err_stream_.str(),
                       "Tablet tablet-id-2 of table 'test' is under-replicated: "
                       "1 replica(s) not RUNNING\n"
                       "  ts-id-0 (<mock>): missing [LEADER]\n"
                       "  ts-id-1 (<mock>): RUNNING\n"
                       "  ts-id-2 (<mock>): RUNNING\n");
 }

 TEST_F(KsckTest, TestTabletNotRunning) {
   CreateOneSmallReplicatedTableWithTabletNotRunning();

   Status s = RunKsck();
   EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
   ASSERT_STR_CONTAINS(
       err_stream_.str(),
       "Tablet tablet-id-0 of table 'test' is unavailable: 3 replica(s) not RUNNING\n"
       "  ts-id-0 (<mock>): bad state [LEADER]\n"
       "    State:       FAILED\n"
       "    Data state:  TABLET_DATA_UNKNOWN\n"
       "    Last status: \n"
       "  ts-id-1 (<mock>): bad state\n"
       "    State:       FAILED\n"
       "    Data state:  TABLET_DATA_UNKNOWN\n"
       "    Last status: \n"
       "  ts-id-2 (<mock>): bad state\n"
       "    State:       FAILED\n"
       "    Data state:  TABLET_DATA_UNKNOWN\n"
       "    Last status: \n");
 }

 } // namespace tools
 } // namespace kudu
	// Licensed to the Apache Software Foundation (ASF) under one
	// or more contributor license agreements. See the NOTICE file
	// distributed with this work for additional information
	// regarding copyright ownership. The ASF licenses this file
	// to you under the Apache License, Version 2.0 (the
	// "License"); you may not use this file except in compliance
	// with the License. You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing,
	// software distributed under the License is distributed on an
	// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	// KIND, either express or implied. See the License for the
	// specific language governing permissions and limitations
	// under the License.

	#include <iosfwd>
	#include <memory>
	#include <unordered_map>

	#include <gflags/gflags.h>
	#include <gtest/gtest.h>

	#include "kudu/gutil/map-util.h"
	#include "kudu/gutil/strings/substitute.h"
	#include "kudu/tools/ksck.h"
	#include "kudu/util/scoped_cleanup.h"
	#include "kudu/util/test_util.h"

	DECLARE_string(color);

	namespace kudu {
	namespace tools {

	using std::shared_ptr;
	using std::static_pointer_cast;
	using std::string;
	using std::unordered_map;
	using strings::Substitute;

	// Import this symbol from ksck.cc so we can introspect the
	// errors being written to stderr.
	extern std::ostream* g_err_stream;

	class MockKsckTabletServer : public KsckTabletServer {
	public:
	explicit MockKsckTabletServer(const string& uuid)
	: KsckTabletServer(uuid),
	fetch_info_status_(Status::OK()),
	address_("<mock>") {
	}

	Status FetchInfo() override {
	timestamp_ = 12345;
	if (fetch_info_status_.ok()) {
	state_ = kFetched;
	} else {
	state_ = kFetchFailed;
	}
	return fetch_info_status_;
	}

	virtual void RunTabletChecksumScanAsync(
	const std::string& tablet_id,
	const Schema& schema,
	const ChecksumOptions& options,
	ChecksumProgressCallbacks* callbacks) OVERRIDE {
	callbacks->Progress(10, 20);
	callbacks->Finished(Status::OK(), 0);
	}

	virtual std::string address() const OVERRIDE {
	return address_;
	}

	// Public because the unit tests mutate this variable directly.
	Status fetch_info_status_;

	private:
	const string address_;
	};

	class MockKsckMaster : public KsckMaster {
	public:
	MockKsckMaster()
	: fetch_info_status_(Status::OK()) {
	}

	virtual Status Connect() OVERRIDE {
	return fetch_info_status_;
	}

	virtual Status RetrieveTabletServers(TSMap* tablet_servers) OVERRIDE {
	*tablet_servers = tablet_servers_;
	return Status::OK();
	}

	virtual Status RetrieveTablesList(vector<shared_ptr<KsckTable>>* tables) OVERRIDE {
	tables->assign(tables_.begin(), tables_.end());
	return Status::OK();
	}

	virtual Status RetrieveTabletsList(const shared_ptr<KsckTable>& table) OVERRIDE {
	return Status::OK();
	}

	// Public because the unit tests mutate these variables directly.
	Status fetch_info_status_;
	TSMap tablet_servers_;
	vector<shared_ptr<KsckTable>> tables_;
	};

	class KsckTest : public KuduTest {
	public:
	KsckTest()
	: master_(new MockKsckMaster()),
	cluster_(new KsckCluster(static_pointer_cast<KsckMaster>(master_))),
	ksck_(new Ksck(cluster_)) {
	FLAGS_color = "never";
	unordered_map<string, shared_ptr<KsckTabletServer>> tablet_servers;
	for (int i = 0; i < 3; i++) {
	string name = Substitute("ts-id-$0", i);
	shared_ptr<MockKsckTabletServer> ts(new MockKsckTabletServer(name));
	InsertOrDie(&tablet_servers, ts->uuid(), ts);
	}
	master_->tablet_servers_.swap(tablet_servers);

	g_err_stream = &err_stream_;
	}

	~KsckTest() {
	g_err_stream = NULL;
	}

	protected:
	void CreateDefaultAssignmentPlan(int tablets_count) {
	while (tablets_count > 0) {
	for (const KsckMaster::TSMap::value_type& entry : master_->tablet_servers_) {
	if (tablets_count-- == 0) return;
	assignment_plan_.push_back(entry.second->uuid());
	}
	}
	}

	void CreateOneTableOneTablet() {
	CreateDefaultAssignmentPlan(1);

	auto table = CreateAndAddTable("test", 1);
	shared_ptr<KsckTablet> tablet(new KsckTablet(table.get(), "tablet-id-1"));
	CreateAndFillTablet(tablet, 1, true, true);
	table->set_tablets({ tablet });
	}

	void CreateOneSmallReplicatedTable() {
	int num_replicas = 3;
	int num_tablets = 3;
	CreateDefaultAssignmentPlan(num_replicas * num_tablets);
	auto table = CreateAndAddTable("test", num_replicas);

	vector<shared_ptr<KsckTablet>> tablets;
	for (int i = 0; i < num_tablets; i++) {
	shared_ptr<KsckTablet> tablet(new KsckTablet(
	table.get(), Substitute("tablet-id-$0", i)));
	CreateAndFillTablet(tablet, num_replicas, true, true);
	tablets.push_back(tablet);
	}
	table->set_tablets(tablets);
	}

	void CreateOneSmallReplicatedTableWithTabletNotRunning() {
	int num_replicas = 3;
	int num_tablets = 3;
	CreateDefaultAssignmentPlan(num_replicas * num_tablets);
	auto table = CreateAndAddTable("test", num_replicas);

	vector<shared_ptr<KsckTablet>> tablets;
	for (int i = 0; i < num_tablets; i++) {
	shared_ptr<KsckTablet> tablet(new KsckTablet(
	table.get(), Substitute("tablet-id-$0", i)));
	CreateAndFillTablet(tablet, num_replicas, true, i != 0);
	tablets.push_back(tablet);
	}
	table->set_tablets(tablets);
	}

	void CreateOneOneTabletReplicatedBrokenTable() {
	// We're placing only two tablets, the 3rd goes nowhere.
	CreateDefaultAssignmentPlan(2);

	auto table = CreateAndAddTable("test", 3);

	shared_ptr<KsckTablet> tablet(new KsckTablet(table.get(), "tablet-id-1"));
	CreateAndFillTablet(tablet, 2, false, true);
	table->set_tablets({ tablet });
	}

	shared_ptr<KsckTable> CreateAndAddTable(const string& name, int num_replicas) {
	shared_ptr<KsckTable> table(new KsckTable(name, Schema(), num_replicas));
	vector<shared_ptr<KsckTable>> tables = { table };
	master_->tables_.assign(tables.begin(), tables.end());
	return table;
	}

	void CreateAndFillTablet(shared_ptr<KsckTablet>& tablet, int num_replicas,
	bool has_leader, bool is_running) {
	vector<shared_ptr<KsckTabletReplica>> replicas;
	if (has_leader) {
	CreateReplicaAndAdd(replicas, tablet->id(), true, is_running);
	num_replicas--;
	}
	for (int i = 0; i < num_replicas; i++) {
	CreateReplicaAndAdd(replicas, tablet->id(), false, is_running);
	}
	tablet->set_replicas(replicas);
	}

	void CreateReplicaAndAdd(vector<shared_ptr<KsckTabletReplica>>& replicas,
	string tablet_id,
	bool is_leader,
	bool is_running) {
	shared_ptr<KsckTabletReplica> replica(new KsckTabletReplica(assignment_plan_.back(),
	is_leader));
	shared_ptr<MockKsckTabletServer> ts = static_pointer_cast<MockKsckTabletServer>(
	master_->tablet_servers_.at(assignment_plan_.back()));

	assignment_plan_.pop_back();
	replicas.push_back(replica);

	// Add the equivalent replica on the tablet server.
	tablet::TabletStatusPB pb;
	pb.set_tablet_id(tablet_id);
	pb.set_table_name("fake-table");
	pb.set_state(is_running ? tablet::RUNNING : tablet::FAILED);
	InsertOrDie(&ts->tablet_status_map_, tablet_id, std::move(pb));
	}

	Status RunKsck() {
	auto c = MakeScopedCleanup([this]() {
	LOG(INFO) << "Ksck output:\n" << err_stream_.str();
	});
	RETURN_NOT_OK(ksck_->CheckMasterRunning());
	RETURN_NOT_OK(ksck_->FetchTableAndTabletInfo());
	RETURN_NOT_OK(ksck_->FetchInfoFromTabletServers());
	RETURN_NOT_OK(ksck_->CheckTablesConsistency());
	return Status::OK();
	}


	shared_ptr<MockKsckMaster> master_;
	shared_ptr<KsckCluster> cluster_;
	shared_ptr<Ksck> ksck_;
	// This is used as a stack. First the unit test is responsible to create a plan to follow, that
	// is the order in which each replica of each tablet will be assigned, starting from the end.
	// So if you have 2 tablets with num_replicas=3 and 3 tablet servers, then to distribute evenly
	// you should have a list that looks like ts1,ts2,ts3,ts3,ts2,ts1 so that the two LEADERS, which
	// are assigned first, end up on ts1 and ts3.
	vector<string> assignment_plan_;

	std::ostringstream err_stream_;
	};

	TEST_F(KsckTest, TestMasterOk) {
	ASSERT_OK(ksck_->CheckMasterRunning());
	}

	TEST_F(KsckTest, TestMasterUnavailable) {
	Status error = Status::NetworkError("Network failure");
	master_->fetch_info_status_ = error;
	ASSERT_TRUE(ksck_->CheckMasterRunning().IsNetworkError());
	}

	TEST_F(KsckTest, TestTabletServersOk) {
	ASSERT_OK(RunKsck());
	}

	TEST_F(KsckTest, TestBadTabletServer) {
	CreateOneSmallReplicatedTable();

	// Mock a failure to connect to one of the tablet servers.
	Status error = Status::NetworkError("Network failure");
	static_pointer_cast<MockKsckTabletServer>(master_->tablet_servers_["ts-id-1"])
	->fetch_info_status_ = error;

	ASSERT_OK(ksck_->CheckMasterRunning());
	ASSERT_OK(ksck_->FetchTableAndTabletInfo());
	Status s = ksck_->FetchInfoFromTabletServers();
	ASSERT_TRUE(s.IsNetworkError()) << "Status returned: " << s.ToString();

	s = ksck_->CheckTablesConsistency();
	EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
	ASSERT_STR_CONTAINS(
	err_stream_.str(),
	"WARNING: Unable to connect to Tablet Server "
	"ts-id-1 (<mock>): Network error: Network failure");
	ASSERT_STR_CONTAINS(
	err_stream_.str(),
	"Tablet tablet-id-0 of table 'test' is under-replicated: 1 replica(s) not RUNNING\n"
	" ts-id-0 (<mock>): RUNNING [LEADER]\n"
	" ts-id-1 (<mock>): TS unavailable\n"
	" ts-id-2 (<mock>): RUNNING\n");
	ASSERT_STR_CONTAINS(
	err_stream_.str(),
	"Tablet tablet-id-1 of table 'test' is under-replicated: 1 replica(s) not RUNNING\n"
	" ts-id-0 (<mock>): RUNNING [LEADER]\n"
	" ts-id-1 (<mock>): TS unavailable\n"
	" ts-id-2 (<mock>): RUNNING\n");
	ASSERT_STR_CONTAINS(
	err_stream_.str(),
	"Tablet tablet-id-2 of table 'test' is under-replicated: 1 replica(s) not RUNNING\n"
	" ts-id-0 (<mock>): RUNNING [LEADER]\n"
	" ts-id-1 (<mock>): TS unavailable\n"
	" ts-id-2 (<mock>): RUNNING\n");
	}

	TEST_F(KsckTest, TestZeroTabletReplicasCheck) {
	ASSERT_OK(RunKsck());
	}

	TEST_F(KsckTest, TestZeroTableCheck) {
	ASSERT_OK(RunKsck());
	}

	TEST_F(KsckTest, TestOneTableCheck) {
	CreateOneTableOneTablet();
	ASSERT_OK(RunKsck());
	ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"0/1 replicas remaining (20B from disk, 10 rows summed)");
	}

	TEST_F(KsckTest, TestOneSmallReplicatedTable) {
	CreateOneSmallReplicatedTable();
	ASSERT_OK(RunKsck());
	ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"0/9 replicas remaining (180B from disk, 90 rows summed)");

	// Test filtering (a non-matching pattern)
	err_stream_.str("");
	ksck_->set_table_filters({"xyz"});
	ASSERT_OK(RunKsck());
	Status s = ksck_->ChecksumData(ChecksumOptions());
	EXPECT_EQ("Not found: No table found. Filter: table_filters=xyz", s.ToString());
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"The cluster doesn't have any matching tables");

	// Test filtering with a matching table pattern.
	err_stream_.str("");
	ksck_->set_table_filters({"te*"});
	ASSERT_OK(RunKsck());
	ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"0/9 replicas remaining (180B from disk, 90 rows summed)");

	// Test filtering with a matching tablet ID pattern.
	err_stream_.str("");
	ksck_->set_table_filters({});
	ksck_->set_tablet_id_filters({"*-id-2"});
	ASSERT_OK(RunKsck());
	ASSERT_OK(ksck_->ChecksumData(ChecksumOptions()));
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"0/3 replicas remaining (60B from disk, 30 rows summed)");
	}

	TEST_F(KsckTest, TestOneOneTabletBrokenTable) {
	CreateOneOneTabletReplicatedBrokenTable();
	Status s = RunKsck();
	EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"Tablet tablet-id-1 of table 'test' is under-replicated: "
	"configuration has 2 replicas vs desired 3");
	}

	TEST_F(KsckTest, TestMismatchedAssignments) {
	CreateOneSmallReplicatedTable();
	shared_ptr<MockKsckTabletServer> ts = static_pointer_cast<MockKsckTabletServer>(
	master_->tablet_servers_.at(Substitute("ts-id-$0", 0)));
	ASSERT_EQ(1, ts->tablet_status_map_.erase("tablet-id-2"));

	Status s = RunKsck();
	EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
	ASSERT_STR_CONTAINS(err_stream_.str(),
	"Tablet tablet-id-2 of table 'test' is under-replicated: "
	"1 replica(s) not RUNNING\n"
	" ts-id-0 (<mock>): missing [LEADER]\n"
	" ts-id-1 (<mock>): RUNNING\n"
	" ts-id-2 (<mock>): RUNNING\n");
	}

	TEST_F(KsckTest, TestTabletNotRunning) {
	CreateOneSmallReplicatedTableWithTabletNotRunning();

	Status s = RunKsck();
	EXPECT_EQ("Corruption: 1 table(s) are bad", s.ToString());
	ASSERT_STR_CONTAINS(
	err_stream_.str(),
	"Tablet tablet-id-0 of table 'test' is unavailable: 3 replica(s) not RUNNING\n"
	" ts-id-0 (<mock>): bad state [LEADER]\n"
	" State: FAILED\n"
	" Data state: TABLET_DATA_UNKNOWN\n"
	" Last status: \n"
	" ts-id-1 (<mock>): bad state\n"
	" State: FAILED\n"
	" Data state: TABLET_DATA_UNKNOWN\n"
	" Last status: \n"
	" ts-id-2 (<mock>): bad state\n"
	" State: FAILED\n"
	" Data state: TABLET_DATA_UNKNOWN\n"
	" Last status: \n");
	}

	} // namespace tools
	} // namespace kudu