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apache / kudu / ab974c7da5b6be220e66aaa819dfc161d162f12b / . / src / kudu / tools / rebalancer_tool-test.cc
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// 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 <algorithm>
#include <atomic>
#include <cstdint>
#include <cstdlib>
#include <functional>
#include <iterator>
#include <map>
#include <memory>
#include <numeric>
#include <optional>
#include <ostream>
#include <string>
#include <thread>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include <gflags/gflags_declare.h>
#include <glog/logging.h>
#include <gtest/gtest.h>
#include "kudu/client/client.h"
#include "kudu/client/schema.h"
#include "kudu/client/shared_ptr.h" // IWYU pragma: keep
#include "kudu/common/partial_row.h"
#include "kudu/consensus/consensus.pb.h"
#include "kudu/consensus/consensus.proxy.h"
#include "kudu/consensus/quorum_util.h"
#include "kudu/gutil/map-util.h"
#include "kudu/gutil/stl_util.h"
#include "kudu/gutil/strings/join.h"
#include "kudu/gutil/strings/substitute.h"
#include "kudu/integration-tests/cluster_itest_util.h"
#include "kudu/integration-tests/cluster_verifier.h"
#include "kudu/integration-tests/test_workload.h"
#include "kudu/integration-tests/ts_itest-base.h"
#include "kudu/master/master.pb.h"
#include "kudu/mini-cluster/external_mini_cluster.h"
#include "kudu/rpc/rpc_controller.h"
#include "kudu/tablet/tablet.pb.h"
#include "kudu/tools/tool_test_util.h"
#include "kudu/tserver/tserver.pb.h"
#include "kudu/util/countdown_latch.h"
#include "kudu/util/monotime.h"
#include "kudu/util/net/net_util.h"
#include "kudu/util/net/sockaddr.h"
#include "kudu/util/random.h"
#include "kudu/util/scoped_cleanup.h"
#include "kudu/util/status.h"
#include "kudu/util/test_macros.h"
#include "kudu/util/test_util.h"
namespace kudu {
class Schema;
} // namespace kudu
DECLARE_int32(num_replicas);
DECLARE_int32(num_tablet_servers);
using kudu::client::KuduClient;
using kudu::client::KuduColumnSchema;
using kudu::client::KuduSchema;
using kudu::client::KuduSchemaBuilder;
using kudu::client::KuduTableAlterer;
using kudu::client::KuduTableCreator;
using kudu::cluster::LocationInfo;
using kudu::itest::TabletServerMap;
using kudu::tserver::ListTabletsResponsePB;
using std::atomic;
using std::back_inserter;
using std::copy;
using std::endl;
using std::ostream;
using std::ostringstream;
using std::string;
using std::thread;
using std::tuple;
using std::unique_ptr;
using std::unordered_map;
using std::unordered_set;
using std::vector;
using strings::Substitute;
namespace kudu {
namespace tools {
// Helper to format info when a tool action fails.
static string ToolRunInfo(const Status& s, const string& out, const string& err) {
ostringstream str;
str << s.ToString() << endl;
str << "stdout: " << out << endl;
str << "stderr: " << err << endl;
return str.str();
}
// Helper macro for tool tests. Use as follows:
//
// ASSERT_TOOL_OK("cluster", "ksck", master_addrs);
//
// The failure Status result of RunKuduTool is usually useless, so this macro
// also logs the stdout and stderr in case of failure, for easier diagnosis.
// TODO(wdberkeley): Add a macro to retrieve stdout or stderr, or a macro for
// when one of those should match a string.
#define ASSERT_TOOL_OK(...) do { \
const vector<string>& _args{__VA_ARGS__}; \
string _out, _err; \
const Status& _s = RunKuduTool(_args, &_out, &_err); \
if (_s.ok()) { \
SUCCEED(); \
} else { \
FAIL() << ToolRunInfo(_s, _out, _err); \
} \
} while (0)
class AdminCliTest : public tserver::TabletServerIntegrationTestBase {
};
TEST_F(AdminCliTest, RebalancerReportOnly) {
static const char kReferenceOutput[] =
R"***(Per-server replica distribution summary:
Statistic | Value
-----------------------+----------
Minimum Replica Count | 0
Maximum Replica Count | 1
Average Replica Count | 0.600000
Per-table replica distribution summary:
Replica Skew | Value
--------------+----------
Minimum | 1
Maximum | 1
Average | 1.000000)***";
FLAGS_num_tablet_servers = 5;
NO_FATALS(BuildAndStart());
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--report_only",
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
// The rebalancer should report on tablet replica distribution. The output
// should match the reference report: the distribution of the replicas
// is 100% repeatable given the number of tables created by the test,
// the replication factor and the number of tablet servers.
ASSERT_STR_CONTAINS(out, kReferenceOutput);
// The actual rebalancing should not run.
ASSERT_STR_NOT_CONTAINS(out, "rebalancing is complete:")
<< ToolRunInfo(s, out, err);
}
class RebalanceStartCriteriaTest :
public AdminCliTest,
public ::testing::WithParamInterface<Kudu1097> {
};
INSTANTIATE_TEST_SUITE_P(, RebalanceStartCriteriaTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
// Make sure the rebalancer doesn't start if a tablet server is down.
// The rebalancer starts only when the dead tablet server is in the
// list of ignored_tservers.
TEST_P(RebalanceStartCriteriaTest, TabletServerIsDown) {
const bool is_343_scheme = (GetParam() == Kudu1097::Enable);
const vector<string> kMasterFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
const vector<string> kTserverFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
FLAGS_num_tablet_servers = 5;
NO_FATALS(BuildAndStart(kTserverFlags, kMasterFlags));
// Shutdown one of the tablet servers.
HostPort ts_host_port;
{
auto* ts = cluster_->tablet_server(0);
ASSERT_NE(nullptr, ts);
ts_host_port = ts->bound_rpc_hostport();
ts->Shutdown();
}
// Rebalancer doesn't start if a tablet server is down.
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString()
}, &out, &err);
ASSERT_TRUE(s.IsRuntimeError()) << ToolRunInfo(s, out, err);
const auto err_msg_pattern = Substitute(
"Illegal state: tablet server .* \\($0\\): "
"unacceptable health status UNAVAILABLE",
ts_host_port.ToString());
ASSERT_STR_MATCHES(err, err_msg_pattern);
}
// Rebalancer starts when specifying the dead tablet server in 'ignored_tservers'.
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + cluster_->tablet_server(0)->uuid()
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
}
}
// Make sure the rebalancer doesn't start if specified an unknown tablet server.
TEST_P(RebalanceStartCriteriaTest, UnknownIgnoredTServer) {
const bool is_343_scheme = (GetParam() == Kudu1097::Enable);
const vector<string> kMasterFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
const vector<string> kTserverFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
FLAGS_num_tablet_servers = 5;
NO_FATALS(BuildAndStart(kTserverFlags, kMasterFlags));
{
string out;
string err;
Status s = RunKuduTool({"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=unknown_tablet_server"},
&out,
&err);
ASSERT_TRUE(s.IsRuntimeError()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(
err, "ignored tserver unknown_tablet_server is not reported among known tservers")
<< "stderr: " << err;
}
{
string out;
string err;
Status s = RunKuduTool({"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + cluster_->tablet_server(0)->uuid()},
&out,
&err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
}
}
TEST_P(RebalanceStartCriteriaTest, TabletServerInMaintenanceMode) {
const bool is_343_scheme = (GetParam() == Kudu1097::Enable);
const vector<string> kMasterFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
const vector<string> kTserverFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
FLAGS_num_tablet_servers = 5;
NO_FATALS(BuildAndStart(kTserverFlags, kMasterFlags));
auto* ts = cluster_->tablet_server(0);
string master_addr = cluster_->master()->bound_rpc_addr().ToString();
// Set the tserver into maintenance mode.
{
string out;
string err;
Status s =
RunKuduTool({"tserver", "state", "enter_maintenance", master_addr, ts->uuid()}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
}
// Rebalancer doesn't start if any tserver is in maintenance mode.
{
string out;
string err;
Status s = RunKuduTool({"cluster", "rebalance", master_addr}, &out, &err);
ASSERT_TRUE(s.IsRuntimeError()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(err, "unacceptable state MAINTENANCE_MODE");
}
// Rebalancer starts when specifying the maintenance tserver in '--ignored_tservers'.
{
string out;
string err;
Status s = RunKuduTool(
{"cluster", "rebalance", master_addr, "--ignored_tservers=" + ts->uuid()}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
}
// Rebalancer starts when specifying '--force_rebalance_replicas_on_maintenance_tservers'.
{
string out;
string err;
Status s = RunKuduTool(
{"cluster", "rebalance", master_addr, "--force_rebalance_replicas_on_maintenance_tservers"},
&out,
&err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
}
// Now exit maintenance mode and rebalancer could start.
{
string out;
string err;
Status s =
RunKuduTool({"tserver", "state", "exit_maintenance", master_addr, ts->uuid()}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
s = RunKuduTool({"cluster", "rebalance", master_addr}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
}
}
// Make sure the rebalancer doesn't start if specified too many ignored tservers.
class RebalanceStartSafetyTest :
public AdminCliTest,
public ::testing::WithParamInterface<Kudu1097> {
};
INSTANTIATE_TEST_SUITE_P(, RebalanceStartSafetyTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
TEST_P(RebalanceStartSafetyTest, TooManyIgnoredTservers) {
const bool is_343_scheme = (GetParam() == Kudu1097::Enable);
const vector<string> kMasterFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
const vector<string> kTserverFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
FLAGS_num_tablet_servers = 5;
NO_FATALS(BuildAndStart(kTserverFlags, kMasterFlags));
// Assign 3 ignored tservers.
vector<string> ignored_tservers;
for (int i = 0; i < 3; i++) {
auto* ts = cluster_->tablet_server(i);
ASSERT_NE(nullptr, ts);
ignored_tservers.emplace_back(ts->uuid());
}
// Assign move_replicas_from_ignored_tservers=false.
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + JoinStrings(ignored_tservers, ","),
"--move_replicas_from_ignored_tservers=false"
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
}
// Assign move_replicas_from_ignored_tservers=true.
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + JoinStrings(ignored_tservers, ","),
"--move_replicas_from_ignored_tservers=true"
}, &out, &err);
ASSERT_TRUE(s.IsRuntimeError()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(err,
"Too many ignored tservers; 2 healthy non-ignored servers exist but 3 are required")
<< "stderr: " << err;
}
}
class RebalanceIgnoredTserversTest :
public AdminCliTest {
};
TEST_F(RebalanceIgnoredTserversTest, Basic) {
SKIP_IF_SLOW_NOT_ALLOWED();
FLAGS_num_tablet_servers = 5;
// Start a cluster with a single tablet.
NO_FATALS(BuildAndStart());
// Pre-condition: all replicas on ignored tservers should be healthy or recovering.
// Here we just ensure the cluster is healthy.
ASSERT_EVENTUALLY([&]() {
ASSERT_TOOL_OK(
"cluster",
"ksck",
cluster_->master()->bound_rpc_addr().ToString()
);
});
// Assign one ignored tserver and move_replicas_from_ignored_tservers=true
// without setting it into maintenance mode.
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + cluster_->tablet_server(0)->uuid(),
"--move_replicas_from_ignored_tservers"
}, &out, &err);
ASSERT_TRUE(s.IsRuntimeError()) << ToolRunInfo(s, out, err);
ASSERT_STR_MATCHES(err, "You should set maintenance mode for tablet server");
}
// Set the ignored tserver into maintenance mode.
{
string out;
string err;
Status s = RunKuduTool({
"tserver",
"state",
"enter_maintenance",
cluster_->master()->bound_rpc_addr().ToString(),
cluster_->tablet_server(0)->uuid()
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
}
// Run the rebalance again.
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + cluster_->tablet_server(0)->uuid(),
"--move_replicas_from_ignored_tservers"
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
// There would be no replica on the ignored tserver after rebalancing.
ASSERT_STR_CONTAINS(out, Substitute("$0 | 0", cluster_->tablet_server(0)->uuid()))
<< "stderr: " << err;
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
}
// Assign two ignored tservers, one of which is unhealthy,
// '-move_replicas_from_ignored_tservers' and
// '-output_replica_distribution_details' are both enabled.
auto* ts = cluster_->tablet_server(1);
ASSERT_NE(nullptr, ts);
ts->Shutdown();
{
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + cluster_->tablet_server(0)->uuid() + "," + ts->uuid(),
"--move_replicas_from_ignored_tservers",
"--output_replica_distribution_details"
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
// The output info would not contain the unhealthy server.
ASSERT_STR_NOT_CONTAINS(out, ts->uuid());
// There would be no replica on the healthy ignored terver after rebalaning.
ASSERT_STR_CONTAINS(out, Substitute("$0 | 0", cluster_->tablet_server(0)->uuid()))
<< "stderr: " << err;
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
}
}
static Status CreateTables(
cluster::ExternalMiniCluster* cluster,
client::KuduClient* client,
const Schema& table_schema,
const string& table_name_pattern,
int num_tables,
int rep_factor,
int num_table_hash_partitions = 3,
int num_table_range_partitions = 0,
vector<string>* table_names = nullptr) {
DCHECK_GE(num_table_range_partitions, 0);
if (num_table_range_partitions != 0 && num_table_range_partitions < 2) {
// That's an artificial restriction to simplify the logic for creating
// range partitions which cover the whole key space.
return Status::InvalidArgument(
"number of range partitions should be at least 2");
}
// Create tables with their tablet replicas landing only on the tablet servers
// which are up and running.
auto client_schema = KuduSchema::FromSchema(table_schema);
for (auto i = 0; i < num_tables; ++i) {
string table_name = Substitute(table_name_pattern, i);
unique_ptr<KuduTableCreator> table_creator(client->NewTableCreator());
table_creator->table_name(table_name);
table_creator->schema(&client_schema);
table_creator->num_replicas(rep_factor);
if (num_table_hash_partitions > 1) {
table_creator->add_hash_partitions({ "key" }, num_table_hash_partitions);
}
for (auto i = 0; i < num_table_range_partitions; ++i) {
unique_ptr<KuduPartialRow> lower_bound(client_schema.NewRow());
unique_ptr<KuduPartialRow> upper_bound(client_schema.NewRow());
if (i == 0) {
RETURN_NOT_OK(lower_bound->SetInt32("key", INT32_MIN));
RETURN_NOT_OK(upper_bound->SetInt32("key", 0));
} else if (i + 1 == num_table_range_partitions) {
RETURN_NOT_OK(lower_bound->SetInt32("key", (i - 1) * 1000));
RETURN_NOT_OK(upper_bound->SetInt32("key", INT32_MAX));
} else {
RETURN_NOT_OK(lower_bound->SetInt32("key", (i - 1) * 1000));
RETURN_NOT_OK(upper_bound->SetInt32("key", i * 1000));
}
table_creator->add_range_partition(lower_bound.release(),
upper_bound.release());
}
RETURN_NOT_OK(table_creator->Create());
RETURN_NOT_OK(RunKuduTool({
"perf",
"loadgen",
cluster->master()->bound_rpc_addr().ToString(),
Substitute("--table_name=$0", table_name),
Substitute("--table_num_replicas=$0", rep_factor),
"--string_fixed=unbalanced_tables_test",
}));
if (table_names) {
table_names->emplace_back(std::move(table_name));
}
}
return Status::OK();
}
// Create tables with unbalanced replica distribution: useful in
// rebalancer-related tests.
static Status CreateUnbalancedTables(
cluster::ExternalMiniCluster* cluster,
client::KuduClient* client,
const Schema& table_schema,
const string& table_name_pattern,
int num_tables,
int rep_factor,
int tserver_idx_from,
int tserver_num,
int tserver_unresponsive_ms,
int num_table_hash_partitions,
int num_table_range_partitions,
vector<string>* table_names = nullptr) {
// Keep running only some tablet servers and shut down the rest.
for (auto i = tserver_idx_from; i < tserver_num; ++i) {
cluster->tablet_server(i)->Shutdown();
}
// Wait for the catalog manager to understand that not all tablet servers
// are available.
SleepFor(MonoDelta::FromMilliseconds(5 * tserver_unresponsive_ms / 4));
RETURN_NOT_OK(CreateTables(
cluster, client, table_schema, table_name_pattern, num_tables, rep_factor,
num_table_hash_partitions, num_table_range_partitions, table_names));
for (auto i = tserver_idx_from; i < tserver_num; ++i) {
RETURN_NOT_OK(cluster->tablet_server(i)->Restart());
}
return Status::OK();
}
// A test to verify that rebalancing works for both 3-4-3 and 3-2-3 replica
// management schemes. During replica movement, a light workload is run against
// every table being rebalanced. This test covers different replication factors.
class RebalanceParamTest :
public AdminCliTest,
public ::testing::WithParamInterface<tuple<int, Kudu1097>> {
};
INSTANTIATE_TEST_SUITE_P(, RebalanceParamTest,
::testing::Combine(::testing::Values(1, 2, 3, 5),
::testing::Values(Kudu1097::Disable, Kudu1097::Enable)));
TEST_P(RebalanceParamTest, Rebalance) {
SKIP_IF_SLOW_NOT_ALLOWED();
const auto& param = GetParam();
const auto kRepFactor = std::get<0>(param);
const auto is_343_scheme = (std::get<1>(param) == Kudu1097::Enable);
constexpr auto kNumTservers = 7;
constexpr auto kNumTables = 5;
const string table_name_pattern = "rebalance_test_table_$0";
constexpr auto kTserverUnresponsiveMs = 3000;
constexpr auto kNumTableHashPartitions = 3;
constexpr auto kNumTableRangePartitions = 0;
const auto timeout = MonoDelta::FromSeconds(30);
const vector<string> kMasterFlags = {
"--allow_unsafe_replication_factor",
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
Substitute("--tserver_unresponsive_timeout_ms=$0", kTserverUnresponsiveMs),
};
const vector<string> kTserverFlags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
FLAGS_num_tablet_servers = kNumTservers;
FLAGS_num_replicas = kRepFactor;
NO_FATALS(BuildAndStart(kTserverFlags, kMasterFlags));
ASSERT_OK(CreateUnbalancedTables(
cluster_.get(), client_.get(), schema_, table_name_pattern, kNumTables,
kRepFactor, kRepFactor + 1, kNumTservers, kTserverUnresponsiveMs,
kNumTableHashPartitions, kNumTableRangePartitions));
// Workloads aren't run for 3-2-3 replica movement with RF = 1 because
// the tablet is unavailable during the move until the target voter replica
// is up and running. That might take some time, and to avoid flakiness or
// setting longer timeouts, RF=1 replicas are moved with no concurrent
// workload running.
//
// TODO(aserbin): clarify why even with 3-4-3 it's a bit flaky now.
vector<unique_ptr<TestWorkload>> workloads;
//if (kRepFactor > 1 || is_343_scheme) {
if (kRepFactor > 1) {
for (auto i = 0; i < kNumTables; ++i) {
const string table_name = Substitute(table_name_pattern, i);
// The workload is light (1 thread, 1 op batches) so that new replicas
// bootstrap and converge quickly.
unique_ptr<TestWorkload> workload(new TestWorkload(cluster_.get()));
workload->set_table_name(table_name);
workload->set_num_replicas(kRepFactor);
workload->set_num_write_threads(1);
workload->set_write_batch_size(1);
workload->set_write_timeout_millis(timeout.ToMilliseconds());
workload->set_already_present_allowed(true);
workload->Setup();
workload->Start();
workloads.emplace_back(std::move(workload));
}
}
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--move_single_replicas=enabled",
};
{
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
}
// Next run should report the cluster as balanced and no replica movement
// should be attempted.
{
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out,
"rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
}
for (auto& workload : workloads) {
workload->StopAndJoin();
}
NO_FATALS(cluster_->AssertNoCrashes());
NO_FATALS(ClusterVerifier(cluster_.get()).CheckCluster());
// Now add a new tablet server into the cluster and make sure the rebalancer
// will re-distribute replicas.
ASSERT_OK(cluster_->AddTabletServer());
{
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
// The cluster was unbalanced, so many replicas should have been moved.
ASSERT_STR_NOT_CONTAINS(out, "(moved 0 replicas)");
}
NO_FATALS(cluster_->AssertNoCrashes());
NO_FATALS(ClusterVerifier(cluster_.get()).CheckCluster());
}
// Working around limitations of older libstdc++.
static const unordered_set<string> kEmptySet = unordered_set<string>();
// Common base for the rebalancer-related test below.
class RebalancingTest : public tserver::TabletServerIntegrationTestBase {
public:
explicit RebalancingTest(int num_tables = 10,
int rep_factor = 3,
int num_tservers = 8,
int tserver_unresponsive_ms = 3000)
: num_tables_(num_tables),
rep_factor_(rep_factor),
num_tservers_(num_tservers),
tserver_unresponsive_ms_(tserver_unresponsive_ms) {
master_flags_ = {
Substitute("--tserver_unresponsive_timeout_ms=$0",
tserver_unresponsive_ms_),
};
}
virtual bool is_343_scheme() const = 0;
virtual int num_hash_partitions_for_test_tables() const {
return 3;
}
virtual int num_range_partitions_for_test_tables() const {
return 0;
}
protected:
static const char* const kExitOnSignalStr;
static const char* const kTableNamePattern;
void Prepare(const vector<string>& extra_tserver_flags = {},
const vector<string>& extra_master_flags = {},
const LocationInfo& location_info = {},
const unordered_set<string>& empty_locations = kEmptySet,
vector<string>* created_tables_names = nullptr) {
const auto& scheme_flag = Substitute(
"--raft_prepare_replacement_before_eviction=$0", is_343_scheme());
master_flags_.push_back(scheme_flag);
tserver_flags_.push_back(scheme_flag);
copy(extra_tserver_flags.begin(), extra_tserver_flags.end(),
back_inserter(tserver_flags_));
copy(extra_master_flags.begin(), extra_master_flags.end(),
back_inserter(master_flags_));
FLAGS_num_tablet_servers = num_tservers_;
FLAGS_num_replicas = rep_factor_;
NO_FATALS(BuildAndStart(tserver_flags_, master_flags_, location_info,
/*create_table=*/ false));
if (location_info.empty()) {
ASSERT_OK(CreateUnbalancedTables(
cluster_.get(), client_.get(), schema_, kTableNamePattern,
num_tables_, rep_factor_, rep_factor_ + 1, num_tservers_,
tserver_unresponsive_ms_,
num_hash_partitions_for_test_tables(),
num_range_partitions_for_test_tables(),
created_tables_names));
} else {
ASSERT_OK(CreateTablesExcludingLocations(empty_locations,
kTableNamePattern,
created_tables_names));
}
}
// Create tables placing their tablet replicas everywhere but not at the
// tablet servers in the specified locations. This is similar to
// CreateUnbalancedTables() but the set of tablet servers to avoid is defined
// by the set of the specified locations.
//
// Note: 'table_name_pattern' is used to describe the table names created by this
// function. Each call to this function can create different batch of tables with
// this parameter set.
Status CreateTablesExcludingLocations(
const unordered_set<string>& excluded_locations,
const string& table_name_pattern = kTableNamePattern,
vector<string>* table_names = nullptr) {
// Shutdown all tablet servers in the specified locations so no tablet
// replicas would be hosted by those servers.
unordered_set<string> seen_locations;
if (!excluded_locations.empty()) {
for (const auto& elem : tablet_servers_) {
auto* ts = elem.second;
if (ContainsKey(excluded_locations, ts->location)) {
cluster_->tablet_server_by_uuid(ts->uuid())->Shutdown();
EmplaceIfNotPresent(&seen_locations, ts->location);
}
}
}
// Sanity check: every specified location should have been seen, otherwise
// something is wrong with the tablet servers' registration.
CHECK_EQ(excluded_locations.size(), seen_locations.size());
// Wait for the catalog manager to understand that not all tablet servers
// are available.
SleepFor(MonoDelta::FromMilliseconds(5 * tserver_unresponsive_ms_ / 4));
RETURN_NOT_OK(CreateTables(cluster_.get(), client_.get(), schema_,
table_name_pattern, num_tables_, rep_factor_,
num_hash_partitions_for_test_tables(),
num_range_partitions_for_test_tables(),
table_names));
// Start tablet servers at the excluded locations.
if (!excluded_locations.empty()) {
for (const auto& elem : tablet_servers_) {
auto* ts = elem.second;
if (ContainsKey(excluded_locations, ts->location)) {
RETURN_NOT_OK(cluster_->tablet_server_by_uuid(ts->uuid())->Restart());
}
}
}
return Status::OK();
}
// Create tables placing their tablet replicas elsewhere but not at the specified
// number of tservers in the specified locations.
Status CreateTablesExcludingTserversInLocations(
const unordered_map<string, int>& excluded_tserver_by_location,
const string& table_name_pattern = kTableNamePattern,
vector<string>* table_names = nullptr) {
unordered_map<string, int> excluded_tservers = excluded_tserver_by_location;
vector<string> excluded_tserver_uuids;
// Shutdown some tablet servers in the specified locations so no tablet
// replicas would be hosted by those servers.
if (!excluded_tservers.empty()) {
for (const auto& elem : tablet_servers_) {
auto* ts = elem.second;
if (ContainsKey(excluded_tservers, ts->location)
&& excluded_tservers[ts->location] > 0) {
excluded_tserver_uuids.push_back(ts->uuid());
--excluded_tservers[ts->location];
cluster_->tablet_server_by_uuid(ts->uuid())->Shutdown();
}
}
}
for (const auto& elem : excluded_tservers) {
CHECK_EQ(0, elem.second);
}
// Wait for the catalog manager to understand that not all tablet servers
// are available.
SleepFor(MonoDelta::FromMilliseconds(5 * tserver_unresponsive_ms_ / 4));
RETURN_NOT_OK(CreateTables(cluster_.get(), client_.get(), schema_,
table_name_pattern, num_tables_, rep_factor_,
num_hash_partitions_for_test_tables(),
num_range_partitions_for_test_tables(),
table_names));
// Start tablet servers at the excluded locations.
for (const auto& uuid : excluded_tserver_uuids) {
RETURN_NOT_OK(cluster_->tablet_server_by_uuid(uuid)->Restart());
}
return Status::OK();
}
// When the rebalancer starts moving replicas, ksck detects corruption
// (that's why RuntimeError), seeing affected tables as non-healthy
// with data state of corresponding tablets as TABLET_DATA_COPYING. If using
// this method, it's a good idea to inject some latency into tablet copying
// to be able to spot the TABLET_DATA_COPYING state, see the
// '--tablet_copy_download_file_inject_latency_ms' flag for tservers.
bool IsRebalancingInProgress() {
string out;
const auto s = RunKuduTool({
"cluster",
"ksck",
cluster_->master()->bound_rpc_addr().ToString(),
}, &out);
return s.IsRuntimeError() &&
out.find("Data state: TABLET_DATA_COPYING") != string::npos;
}
const int num_tables_;
const int rep_factor_;
const int num_tservers_;
const int tserver_unresponsive_ms_;
vector<string> tserver_flags_;
vector<string> master_flags_;
};
const char* const RebalancingTest::kExitOnSignalStr = "kudu: process exited on signal";
const char* const RebalancingTest::kTableNamePattern = "rebalance_test_table_$0";
typedef testing::WithParamInterface<Kudu1097> Kudu1097ParamTest;
// If an ignored tablet server went down during the process of copying data,
// the rebalancer would ignore the health state of the ignored tablet server,
// and replicas on it, run the rebalancing on the other tablet servers and
// exit normally.
class IgnoredTserverGoesDownDuringRebalancingTest : public RebalancingTest {
public:
IgnoredTserverGoesDownDuringRebalancingTest()
: RebalancingTest(/*num_tables=*/ 5) {
}
bool is_343_scheme() const override {
return true;
}
};
TEST_F(IgnoredTserverGoesDownDuringRebalancingTest, TserverDown) {
SKIP_IF_SLOW_NOT_ALLOWED();
const vector<string> kTserverExtraFlags = {
// Slow down tablet copy to make rebalancing step running longer
// and become observable via tablet data states output by ksck.
"--tablet_copy_download_file_inject_latency_ms=1500",
"--follower_unavailable_considered_failed_sec=30",
};
NO_FATALS(Prepare(kTserverExtraFlags));
// Pre-condition: 'kudu cluster ksck' should be happy with the cluster state
// shortly after initial setup.
ASSERT_EVENTUALLY([&]() {
ASSERT_TOOL_OK(
"cluster",
"ksck",
cluster_->master()->bound_rpc_addr().ToString()
);
});
const uint32_t ignored_tserver_idx = 0;
// Set the ignored tserver into maintenance mode.
{
string out;
string err;
Status s = RunKuduTool({
"tserver",
"state",
"enter_maintenance",
cluster_->master()->bound_rpc_addr().ToString(),
cluster_->tablet_server(ignored_tserver_idx)->uuid()
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
}
atomic<bool> run(true);
// The thread that shuts down the ignored tserver.
thread stopper([&]() {
while (run && !IsRebalancingInProgress()) {
SleepFor(MonoDelta::FromMilliseconds(10));
}
// All right, it's time to stop the ignored tserver.
cluster_->tablet_server(ignored_tserver_idx)->Shutdown();
});
auto stopper_cleanup = MakeScopedCleanup([&]() {
run = false;
stopper.join();
});
{
string out;
string err;
const auto s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + cluster_->tablet_server(ignored_tserver_idx)->uuid(),
"--move_replicas_from_ignored_tservers",
// Limiting the number of replicas to move. This is to make the rebalancer
// run longer, making sure the rebalancing is in progress when the tablet
// server goes down.
"--max_moves_per_server=1",
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
// The rebalancer tool should not crash.
ASSERT_STR_NOT_CONTAINS(s.ToString(), kExitOnSignalStr);
// Restart the ignored tablet server
ASSERT_OK(cluster_->tablet_server(ignored_tserver_idx)->Restart());
NO_FATALS(cluster_->AssertNoCrashes());
// Report replica distribution.
{
string out;
string err;
const auto s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--output_replica_distribution_details",
"--report_only",
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
// There would be some replicas on the ignored tablet server,
// they hasn't been moved to other tablet servers by the rebalancer tool.
ASSERT_STR_NOT_CONTAINS(out,
Substitute("$0 | $1 | 0",
cluster_->tablet_server(ignored_tserver_idx)->uuid(),
cluster_->tablet_server(ignored_tserver_idx)->bound_rpc_addr().ToString()));
}
}
run = false;
stopper.join();
stopper_cleanup.cancel();
NO_FATALS(cluster_->AssertNoCrashes());
}
// Make sure the rebalancer is able to do its job if running concurrently
// with DDL activity on the cluster.
class DDLDuringRebalancingTest : public RebalancingTest,
public Kudu1097ParamTest {
public:
DDLDuringRebalancingTest()
: RebalancingTest(/*num_tables=*/ 20) {
}
bool is_343_scheme() const override {
return GetParam() == Kudu1097::Enable;
}
};
INSTANTIATE_TEST_SUITE_P(, DDLDuringRebalancingTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
TEST_P(DDLDuringRebalancingTest, TablesCreatedAndDeletedDuringRebalancing) {
SKIP_IF_SLOW_NOT_ALLOWED();
NO_FATALS(Prepare());
// The latch that controls the lifecycle of the concurrent DDL activity.
CountDownLatch run_latch(1);
thread creator([&]() {
auto client_schema = KuduSchema::FromSchema(schema_);
for (auto idx = 0; ; ++idx) {
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(500))) {
break;
}
const string table_name = Substitute("rebalancer_extra_table_$0", idx++);
unique_ptr<KuduTableCreator> table_creator(client_->NewTableCreator());
CHECK_OK(table_creator->table_name(table_name)
.schema(&client_schema)
.add_hash_partitions({ "key" }, 3)
.num_replicas(rep_factor_)
.Create());
}
});
auto creator_cleanup = MakeScopedCleanup([&]() {
run_latch.CountDown();
creator.join();
});
thread deleter([&]() {
for (auto idx = 0; idx < num_tables_; ++idx) {
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(500))) {
break;
}
CHECK_OK(client_->DeleteTable(Substitute(kTableNamePattern, idx++)));
}
});
auto deleter_cleanup = MakeScopedCleanup([&]() {
run_latch.CountDown();
deleter.join();
});
thread alterer([&]() {
const string kTableName = "rebalancer_dynamic_table";
const string kNewTableName = "rebalancer_dynamic_table_new_name";
while (true) {
// Create table.
{
KuduSchema schema;
KuduSchemaBuilder builder;
builder.AddColumn("key")->Type(KuduColumnSchema::INT64)->
NotNull()->
PrimaryKey();
builder.AddColumn("a")->Type(KuduColumnSchema::INT64);
CHECK_OK(builder.Build(&schema));
unique_ptr<KuduTableCreator> table_creator(client_->NewTableCreator());
CHECK_OK(table_creator->table_name(kTableName)
.schema(&schema)
.set_range_partition_columns({})
.num_replicas(rep_factor_)
.Create());
}
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(100))) {
break;
}
// Drop a column.
{
unique_ptr<KuduTableAlterer> alt(client_->NewTableAlterer(kTableName));
alt->DropColumn("a");
CHECK_OK(alt->Alter());
}
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(100))) {
break;
}
// Add back the column with different type.
{
unique_ptr<KuduTableAlterer> alt(client_->NewTableAlterer(kTableName));
alt->AddColumn("a")->Type(KuduColumnSchema::STRING);
CHECK_OK(alt->Alter());
}
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(100))) {
break;
}
// Rename the table.
{
unique_ptr<KuduTableAlterer> alt(client_->NewTableAlterer(kTableName));
alt->RenameTo(kNewTableName);
CHECK_OK(alt->Alter());
}
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(100))) {
break;
}
// Drop the renamed table.
CHECK_OK(client_->DeleteTable(kNewTableName));
if (run_latch.WaitFor(MonoDelta::FromMilliseconds(100))) {
break;
}
}
});
auto alterer_cleanup = MakeScopedCleanup([&]() {
run_latch.CountDown();
alterer.join();
});
thread timer([&]() {
SleepFor(MonoDelta::FromSeconds(30));
run_latch.CountDown();
});
auto timer_cleanup = MakeScopedCleanup([&]() {
timer.join();
});
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
};
// Run the rebalancer concurrently with the DDL operations. The second run
// of the rebalancer (the second run starts after joining the timer thread)
// is necessary to balance the cluster after the DDL activity stops: that's
// the easiest way to make sure the rebalancer will take into account
// all DDL changes that happened.
//
// The signal to terminate the DDL activity (done via run_latch.CountDown())
// is sent from a separate timer thread instead of doing SleepFor() after
// the first run of the rebalancer followed by run_latch.CountDown().
// That's to avoid dependency on the rebalancer behavior if it spots on-going
// DDL activity and continues running over and over again.
for (auto i = 0; i < 2; ++i) {
if (i == 1) {
timer.join();
timer_cleanup.cancel();
// Wait for all the DDL activity to complete.
alterer.join();
alterer_cleanup.cancel();
deleter.join();
deleter_cleanup.cancel();
creator.join();
creator_cleanup.cancel();
}
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
}
// Next (3rd) run should report the cluster as balanced and
// no replica movement should be attempted.
{
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out,
"rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
}
NO_FATALS(cluster_->AssertNoCrashes());
NO_FATALS(ClusterVerifier(cluster_.get()).CheckCluster());
}
// Make sure it's safe to run multiple rebalancers concurrently. The rebalancers
// might report errors, but they should not get stuck and the cluster should
// remain in good shape (i.e. no crashes, no data inconsistencies). Re-running a
// single rebalancer session again should bring the cluster to a balanced state.
class ConcurrentRebalancersTest : public RebalancingTest,
public Kudu1097ParamTest {
public:
ConcurrentRebalancersTest()
: RebalancingTest(/*num_tables=*/ 10) {
}
bool is_343_scheme() const override {
return GetParam() == Kudu1097::Enable;
}
};
INSTANTIATE_TEST_SUITE_P(, ConcurrentRebalancersTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
TEST_P(ConcurrentRebalancersTest, TwoConcurrentRebalancers) {
SKIP_IF_SLOW_NOT_ALLOWED();
NO_FATALS(Prepare());
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
};
const auto runner_func = [&]() {
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
if (!s.ok()) {
// One might expect a bad status returned: e.g., due to some race so
// the rebalancer didn't able to make progress for more than
// --max_staleness_interval_sec, etc.
LOG(INFO) << "rebalancer run info: " << ToolRunInfo(s, out, err);
}
// Should not exit on a signal: not expecting SIGSEGV, SIGABRT, etc.
return s.ToString().find(kExitOnSignalStr) == string::npos;
};
const constexpr auto kNumConcurrentRunners = 5;
CountDownLatch start_synchronizer(1);
vector<thread> concurrent_runners;
concurrent_runners.reserve(kNumConcurrentRunners);
for (auto i = 0; i < kNumConcurrentRunners; ++i) {
concurrent_runners.emplace_back([&]() {
start_synchronizer.Wait();
CHECK(runner_func());
});
}
// Run rebalancers concurrently and wait for their completion.
start_synchronizer.CountDown();
for (auto& runner : concurrent_runners) {
runner.join();
}
NO_FATALS(cluster_->AssertNoCrashes());
NO_FATALS(ClusterVerifier(cluster_.get()).CheckCluster());
{
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
}
// Next run should report the cluster as balanced and no replica movement
// should be attempted: at least one run of the rebalancer prior to this
// should succeed, so next run is about running the tool against already
// balanced cluster.
{
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out,
"rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
}
NO_FATALS(cluster_->AssertNoCrashes());
NO_FATALS(ClusterVerifier(cluster_.get()).CheckCluster());
}
// The rebalancer should stop and exit upon detecting a tablet server that
// went down. That's a simple and effective way of preventing concurrent replica
// movement by the rebalancer and the automatic re-replication (the catalog
// manager tries to move replicas from the unreachable tablet server).
class TserverGoesDownDuringRebalancingTest : public RebalancingTest,
public Kudu1097ParamTest {
public:
TserverGoesDownDuringRebalancingTest()
: RebalancingTest(/*num_tables=*/ 5) {
}
bool is_343_scheme() const override {
return GetParam() == Kudu1097::Enable;
}
};
INSTANTIATE_TEST_SUITE_P(, TserverGoesDownDuringRebalancingTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
TEST_P(TserverGoesDownDuringRebalancingTest, TserverDown) {
SKIP_IF_SLOW_NOT_ALLOWED();
const vector<string> kTserverExtraFlags = {
// Slow down tablet copy to make rebalancing step running longer
// and become observable via tablet data states output by ksck.
"--tablet_copy_download_file_inject_latency_ms=1500",
"--follower_unavailable_considered_failed_sec=30",
};
NO_FATALS(Prepare(kTserverExtraFlags));
// Pre-condition: 'kudu cluster ksck' should be happy with the cluster state
// shortly after initial setup.
ASSERT_EVENTUALLY([&]() {
ASSERT_TOOL_OK(
"cluster",
"ksck",
cluster_->master()->bound_rpc_addr().ToString()
);
});
Random r(SeedRandom());
const uint32_t shutdown_tserver_idx = r.Next() % num_tservers_;
atomic<bool> run(true);
// The thread that shuts down the selected tablet server.
thread stopper([&]() {
while (run && !IsRebalancingInProgress()) {
SleepFor(MonoDelta::FromMilliseconds(10));
}
// All right, it's time to stop the selected tablet server.
cluster_->tablet_server(shutdown_tserver_idx)->Shutdown();
});
auto stopper_cleanup = MakeScopedCleanup([&]() {
run = false;
stopper.join();
});
{
string out;
string err;
const auto s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
// Limiting the number of replicas to move. This is to make the rebalancer
// run longer, making sure the rebalancing is in progress when the tablet
// server goes down.
"--max_moves_per_server=1",
}, &out, &err);
ASSERT_TRUE(s.IsRuntimeError()) << ToolRunInfo(s, out, err);
// The rebalancer tool should not crash.
ASSERT_STR_NOT_CONTAINS(s.ToString(), kExitOnSignalStr);
ASSERT_STR_MATCHES(
err, "Illegal state: tablet server .* \\(.*\\): "
"unacceptable health status UNAVAILABLE");
}
run = false;
stopper.join();
stopper_cleanup.cancel();
ASSERT_OK(cluster_->tablet_server(shutdown_tserver_idx)->Restart());
NO_FATALS(cluster_->AssertNoCrashes());
}
// The rebalancer should continue working and complete rebalancing successfully
// if a new tablet server is added while the cluster is being rebalanced.
class TserverAddedDuringRebalancingTest : public RebalancingTest,
public Kudu1097ParamTest {
public:
TserverAddedDuringRebalancingTest()
: RebalancingTest(/*num_tables=*/ 10) {
}
bool is_343_scheme() const override {
return GetParam() == Kudu1097::Enable;
}
};
INSTANTIATE_TEST_SUITE_P(, TserverAddedDuringRebalancingTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
TEST_P(TserverAddedDuringRebalancingTest, TserverStarts) {
SKIP_IF_SLOW_NOT_ALLOWED();
const vector<string> kTserverExtraFlags = {
// Slow down tablet copy to make rebalancing step running longer
// and become observable via tablet data states output by ksck.
"--tablet_copy_download_file_inject_latency_ms=1500",
"--follower_unavailable_considered_failed_sec=30",
};
NO_FATALS(Prepare(kTserverExtraFlags));
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
};
atomic<bool> run(true);
thread runner([&]() {
while (run) {
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
CHECK(s.ok()) << ToolRunInfo(s, out, err);
}
});
auto runner_cleanup = MakeScopedCleanup([&]() {
run = false;
runner.join();
});
while (!IsRebalancingInProgress()) {
SleepFor(MonoDelta::FromMilliseconds(10));
}
// It's time to sneak in and add new tablet server.
ASSERT_OK(cluster_->AddTabletServer());
run = false;
runner.join();
runner_cleanup.cancel();
// The rebalancer should not fail, and eventually, after a new tablet server
// is added, the cluster should become balanced.
ASSERT_EVENTUALLY([&]() {
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out,
"rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
});
NO_FATALS(cluster_->AssertNoCrashes());
NO_FATALS(ClusterVerifier(cluster_.get()).CheckCluster());
}
// Run rebalancer in 'election storms' environment and make sure the rebalancer
// does not exit prematurely or exhibit any other unexpected behavior.
class RebalancingDuringElectionStormTest : public RebalancingTest,
public Kudu1097ParamTest {
public:
bool is_343_scheme() const override {
return GetParam() == Kudu1097::Enable;
}
};
INSTANTIATE_TEST_SUITE_P(, RebalancingDuringElectionStormTest,
::testing::Values(Kudu1097::Disable, Kudu1097::Enable));
TEST_P(RebalancingDuringElectionStormTest, RoundRobin) {
SKIP_IF_SLOW_NOT_ALLOWED();
NO_FATALS(Prepare());
atomic<bool> elector_run(true);
#if defined(ADDRESS_SANITIZER) || defined(THREAD_SANITIZER)
// The timeout is a time-to-run for the stormy elector thread as well.
// Making longer timeout for workload in case of TSAN/ASAN is not needed:
// having everything generated written is not required.
const auto timeout = MonoDelta::FromSeconds(5);
#else
const auto timeout = MonoDelta::FromSeconds(10);
#endif
const auto start_time = MonoTime::Now();
thread elector([&]() {
// Mininum viable divider for modulo ('%') to allow the result to grow by
// the rules below.
auto max_sleep_ms = 2.0;
while (elector_run && MonoTime::Now() < start_time + timeout) {
for (const auto& e : tablet_servers_) {
const auto& ts_uuid = e.first;
const auto* ts = e.second;
vector<ListTabletsResponsePB::StatusAndSchemaPB> tablets;
auto const s = itest::ListTablets(ts, timeout, &tablets);
if (!s.ok()) {
LOG(WARNING) << ts_uuid << ": failed to get tablet list :"
<< s.ToString();
continue;
}
consensus::ConsensusServiceProxy proxy(
cluster_->messenger(),
cluster_->tablet_server_by_uuid(ts_uuid)->bound_rpc_addr(),
"tserver " + ts_uuid);
for (const auto& tablet : tablets) {
const auto& tablet_id = tablet.tablet_status().tablet_id();
consensus::RunLeaderElectionRequestPB req;
req.set_tablet_id(tablet_id);
req.set_dest_uuid(ts_uuid);
rpc::RpcController rpc;
rpc.set_timeout(timeout);
consensus::RunLeaderElectionResponsePB resp;
WARN_NOT_OK(proxy.RunLeaderElection(req, &resp, &rpc),
Substitute("failed to start election for tablet $0",
tablet_id));
}
if (!elector_run || start_time + timeout <= MonoTime::Now()) {
break;
}
auto sleep_ms = rand() % static_cast<int>(max_sleep_ms);
SleepFor(MonoDelta::FromMilliseconds(sleep_ms));
max_sleep_ms = std::min(max_sleep_ms * 1.1, 2000.0);
}
}
});
auto elector_cleanup = MakeScopedCleanup([&]() {
elector_run = false;
elector.join();
});
#if !defined(ADDRESS_SANITIZER) && !defined(THREAD_SANITIZER)
vector<unique_ptr<TestWorkload>> workloads;
for (auto i = 0; i < num_tables_; ++i) {
const string table_name = Substitute(kTableNamePattern, i);
// The workload is light (1 thread, 1 op batches) and lenient to failures.
unique_ptr<TestWorkload> workload(new TestWorkload(cluster_.get()));
workload->set_table_name(table_name);
workload->set_num_replicas(rep_factor_);
workload->set_num_write_threads(1);
workload->set_write_batch_size(1);
workload->set_write_timeout_millis(timeout.ToMilliseconds());
workload->set_already_present_allowed(true);
workload->set_remote_error_allowed(true);
workload->set_timeout_allowed(true);
workload->Setup();
workload->Start();
workloads.emplace_back(std::move(workload));
}
#endif
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
};
while (MonoTime::Now() < start_time + timeout) {
// Rebalancer should not report any errors even if it's an election storm
// unless a tablet server is reported as unavailable by ksck: the latter
// usually happens because GetConsensusState requests are dropped due to
// backpressure.
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
if (s.ok()) {
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< ToolRunInfo(s, out, err);
} else {
ASSERT_STR_CONTAINS(err, "unacceptable health status UNAVAILABLE")
<< ToolRunInfo(s, out, err);
}
}
elector_run = false;
elector.join();
elector_cleanup.cancel();
#if !defined(ADDRESS_SANITIZER) && !defined(THREAD_SANITIZER)
for (auto& workload : workloads) {
workload->StopAndJoin();
}
#endif
// There might be some re-replication started as a result of election storm,
// etc. Eventually, the system should heal itself and 'kudu cluster ksck'
// should report no issues.
ASSERT_EVENTUALLY([&]() {
ASSERT_TOOL_OK(
"cluster",
"ksck",
cluster_->master()->bound_rpc_addr().ToString()
);
});
// The rebalancer should successfully rebalance the cluster after ksck
// reported 'all is well'.
{
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< ToolRunInfo(s, out, err);
}
NO_FATALS(cluster_->AssertNoCrashes());
}
// A test to verify how the rebalancer handles replicas of single-replica
// tablets in case of various values of the '--move_single_replicas' flag
// and replica management schemes.
class RebalancerAndSingleReplicaTablets :
public AdminCliTest,
public ::testing::WithParamInterface<tuple<string, Kudu1097>> {
};
INSTANTIATE_TEST_SUITE_P(, RebalancerAndSingleReplicaTablets,
::testing::Combine(::testing::Values("auto", "enabled", "disabled"),
::testing::Values(Kudu1097::Disable, Kudu1097::Enable)));
TEST_P(RebalancerAndSingleReplicaTablets, SingleReplicasStayOrMove) {
SKIP_IF_SLOW_NOT_ALLOWED();
constexpr auto kRepFactor = 1;
constexpr auto kNumTservers = 2 * (kRepFactor + 1);
constexpr auto kNumTables = kNumTservers;
constexpr auto kTserverUnresponsiveMs = 3000;
const auto& param = GetParam();
const auto& move_single_replica = std::get<0>(param);
const auto is_343_scheme = (std::get<1>(param) == Kudu1097::Enable);
const string table_name_pattern = "rebalance_test_table_$0";
const vector<string> master_flags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
Substitute("--tserver_unresponsive_timeout_ms=$0", kTserverUnresponsiveMs),
};
const vector<string> tserver_flags = {
Substitute("--raft_prepare_replacement_before_eviction=$0", is_343_scheme),
};
FLAGS_num_tablet_servers = kNumTservers;
FLAGS_num_replicas = kRepFactor;
NO_FATALS(BuildAndStart(tserver_flags, master_flags));
// Keep running only (kRepFactor + 1) tablet servers and shut down the rest.
for (auto i = kRepFactor + 1; i < kNumTservers; ++i) {
cluster_->tablet_server(i)->Shutdown();
}
// Wait for the catalog manager to understand that only (kRepFactor + 1)
// tablet servers are available.
SleepFor(MonoDelta::FromMilliseconds(5 * kTserverUnresponsiveMs / 4));
// Create few tables with their tablet replicas landing only on those
// (kRepFactor + 1) running tablet servers.
auto client_schema = KuduSchema::FromSchema(schema_);
for (auto i = 0; i < kNumTables; ++i) {
const string table_name = Substitute(table_name_pattern, i);
unique_ptr<KuduTableCreator> table_creator(client_->NewTableCreator());
ASSERT_OK(table_creator->table_name(table_name)
.schema(&client_schema)
.add_hash_partitions({ "key" }, 3)
.num_replicas(kRepFactor)
.Create());
ASSERT_TOOL_OK(
"perf",
"loadgen",
cluster_->master()->bound_rpc_addr().ToString(),
Substitute("--table_name=$0", table_name),
// Don't need much data in there.
"--num_threads=1",
"--num_rows_per_thread=1",
);
}
for (auto i = kRepFactor + 1; i < kNumTservers; ++i) {
ASSERT_OK(cluster_->tablet_server(i)->Restart());
}
string out;
string err;
const Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
Substitute("--move_single_replicas=$0", move_single_replica),
"--v=1", // We'll be looking for a VLOG message about single replicas.
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
if (move_single_replica == "enabled" ||
(move_single_replica == "auto" && is_343_scheme)) {
// Should move appropriate replicas of single-replica tablets.
ASSERT_STR_NOT_CONTAINS(out,
"rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
ASSERT_STR_NOT_CONTAINS(err, "has single replica, skipping");
} else {
ASSERT_STR_CONTAINS(out,
"rebalancing is complete: cluster is balanced (moved 0 replicas)")
<< "stderr: " << err;
ASSERT_STR_MATCHES(err, "tablet .* of table '.*' (.*) has single replica, skipping");
}
NO_FATALS(cluster_->AssertNoCrashes());
ClusterVerifier v(cluster_.get());
NO_FATALS(v.CheckCluster());
}
// Basic fixture for the rebalancer tests.
class LocationAwareRebalancingBasicTest : public RebalancingTest {
public:
LocationAwareRebalancingBasicTest()
: RebalancingTest(/*num_tables=*/ 12,
/*rep_factor=*/ 3,
/*num_tservers=*/ 6) {
}
bool is_343_scheme() const override {
// These tests are for the 3-4-3 replica management scheme only.
return true;
}
};
// Verifying the very basic functionality of the location-aware rebalancer:
// given the very simple cluster configuration of 6 tablet servers spread
// among 3 locations (2+2+2) and 12 tables with RF=3, the initially
// imbalanced distribution of the replicas should become more balanced
// and the placement policy constraints should be reimposed after running
// the rebalancer tool.
TEST_F(LocationAwareRebalancingBasicTest, Basic) {
SKIP_IF_SLOW_NOT_ALLOWED();
const LocationInfo location_info = { { "/A", 2 }, { "/B", 2 }, { "/C", 2 }, };
vector<string> table_names;
NO_FATALS(Prepare({}, {}, location_info, kEmptySet, &table_names));
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
};
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_NOT_CONTAINS(s.ToString(), kExitOnSignalStr);
NO_FATALS(cluster_->AssertNoCrashes());
ClusterVerifier v(cluster_.get());
NO_FATALS(v.CheckCluster());
unordered_map<string, itest::TServerDetails*> ts_map;
ASSERT_OK(itest::CreateTabletServerMap(cluster_->master_proxy(0),
cluster_->messenger(),
&ts_map));
ValueDeleter deleter(&ts_map);
// Build tablet server UUID --> location map.
unordered_map<string, string> location_by_ts_id;
for (const auto& elem : ts_map) {
EmplaceOrDie(&location_by_ts_id, elem.first, elem.second->location);
}
for (const auto& table_name : table_names) {
master::GetTableLocationsResponsePB table_locations;
ASSERT_OK(itest::GetTableLocations(cluster_->master_proxy(),
table_name, MonoDelta::FromSeconds(30),
master::ANY_REPLICA,
/*table_id=*/std::nullopt,
&table_locations));
const auto tablet_num = table_locations.tablet_locations_size();
auto total_table_replica_count = 0;
unordered_map<string, int> total_count_per_location;
for (auto i = 0; i < tablet_num; ++i) {
const auto& location = table_locations.tablet_locations(i);
const auto& tablet_id = location.tablet_id();
unordered_map<string, int> count_per_location;
for (const auto& replica : location.interned_replicas()) {
const auto& ts_id = table_locations.ts_infos(replica.ts_info_idx()).permanent_uuid();
const auto& location = FindOrDie(location_by_ts_id, ts_id);
++LookupOrEmplace(&count_per_location, location, 0);
++LookupOrEmplace(&total_count_per_location, location, 0);
++total_table_replica_count;
}
// Make sure no location has the majority of replicas for the tablet.
for (const auto& elem : count_per_location) {
const auto& location = elem.first;
const auto replica_count = elem.second;
ASSERT_GT(consensus::MajoritySize(rep_factor_), replica_count)
<< Substitute("tablet $0 (table $1): $2 replicas out of $3 total "
"are in location $4",
tablet_id, table_name, replica_count, rep_factor_,
location);
}
// Verify the overall replica distribution for the table.
double avg = static_cast<double>(total_table_replica_count) / location_info.size();
for (const auto& elem : total_count_per_location) {
const auto& location = elem.first;
const auto replica_num = elem.second;
ASSERT_GT(avg + 2, replica_num) << "at location " << location;
ASSERT_LT(avg - 2, replica_num) << "at location " << location;
}
}
}
}
// Test that rebalancing tasks are scheduled for each of the existing locations
// even if running the intra-location rebalancing in a non-concurrent fashion.
TEST_F(LocationAwareRebalancingBasicTest, IntraLocationNoConcurrency) {
SKIP_IF_SLOW_NOT_ALLOWED();
const LocationInfo location_info = { { "/A", 2 }, { "/B", 2 }, { "/C", 2 }, };
vector<string> table_names;
NO_FATALS(Prepare({}, {}, location_info, kEmptySet, &table_names));
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--intra_location_rebalancing_concurrency=1",
};
string out;
string err;
const auto s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_NOT_CONTAINS(s.ToString(), kExitOnSignalStr);
ASSERT_STR_CONTAINS(err, "starting rebalancing within location '/A'");
ASSERT_STR_CONTAINS(err, "starting rebalancing within location '/B'");
ASSERT_STR_CONTAINS(err, "starting rebalancing within location '/C'");
}
class LocationAwareBalanceInfoTest : public RebalancingTest {
public:
LocationAwareBalanceInfoTest()
: RebalancingTest(/*num_tables=*/ 1,
/*rep_factor=*/ 3,
/*num_tservers=*/ 5) {
}
bool is_343_scheme() const override {
// These tests are for the 3-4-3 replica management scheme only.
return true;
}
};
// Verify the output of the location-aware rebalancer against a cluster
// that has multiple locations.
TEST_F(LocationAwareBalanceInfoTest, ReportOnly) {
static const char kReferenceOutput[] =
R"***(Locations load summary:
Location | Load
----------+----------
/A | 3.000000
/B | 3.000000
/C | 0.000000
--------------------------------------------------
Location: /A
--------------------------------------------------
Per-server replica distribution summary:
Statistic | Value
-----------------------+----------
Minimum Replica Count | 3
Maximum Replica Count | 3
Average Replica Count | 3.000000
Per-table replica distribution summary:
Replica Skew | Value
--------------+----------
Minimum | 0
Maximum | 0
Average | 0.000000
--------------------------------------------------
Location: /B
--------------------------------------------------
Per-server replica distribution summary:
Statistic | Value
-----------------------+----------
Minimum Replica Count | 3
Maximum Replica Count | 3
Average Replica Count | 3.000000
Per-table replica distribution summary:
Replica Skew | Value
--------------+----------
Minimum | 0
Maximum | 0
Average | 0.000000
--------------------------------------------------
Location: /C
--------------------------------------------------
Per-server replica distribution summary:
Statistic | Value
-----------------------+----------
Minimum Replica Count | 0
Maximum Replica Count | 0
Average Replica Count | 0.000000
Per-table replica distribution summary:
Replica Skew | Value
--------------+-------
N/A | N/A
Placement policy violations:
Location | Number of non-complying tables | Number of non-complying tablets
----------+--------------------------------+---------------------------------
/B | 1 | 3
)***";
const LocationInfo location_info = { { "/A", 1 }, { "/B", 2 }, { "/C", 2 }, };
NO_FATALS(Prepare({}, {}, location_info, { "/C" }));
string out;
string err;
Status s = RunKuduTool({
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--report_only",
}, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
// The output should match the reference report.
ASSERT_STR_CONTAINS(out, kReferenceOutput);
// The actual rebalancing should not run.
ASSERT_STR_NOT_CONTAINS(out, "rebalancing is complete:")
<< ToolRunInfo(s, out, err);
}
// Parameters for the location-aware rebalancing tests.
typedef struct {
int replication_factor;
int tables_num;
// Information on the distribution of tablet servers among locations.
LocationInfo location_info;
// Locations where tablet servers are shutdown during tablet creation
// to achieve non-balanced tablet replica distribution.
unordered_set<string> excluded_locations;
} LaRebalancingParams;
const LaRebalancingParams kLaRebalancingParams[] = {
// RF=3, 1 table, 1 location, 3 tablet servers.
{ 3, 1,
{
{ { "/A" }, 3 }
},
kEmptySet },
// RF=3, 3 tables, 2 locations, 4 (3 + 1) tablet servers.
{ 3, 3,
{
{ { "/A" }, 3 },
{ { "/B" }, 1 },
},
{ "/B" }
},
// RF=3, 3 tables, 2 locations, 5 (3 + 2) tablet servers.
{ 3, 3,
{
{ { "/A" }, 3 },
{ { "/B" }, 2 },
},
{ "/B" }
},
// RF=3, 3 tables, 2 locations, 6 (3 + 3) tablet servers.
{ 3, 3,
{
{ { "/A" }, 3 },
{ { "/B" }, 3 },
},
{ "/B" }
},
// RF=3, 3 tables, 3 locations, 6 (3 + 2 + 1) tablet servers.
{ 3, 3,
{
{ { "/A" }, 3 },
{ { "/B" }, 2 },
{ { "/C" }, 1 },
},
{ "/B" }
},
// RF=5, 3 locations, 4 tables, 8 (3 + 2 + 3) tablet servers.
{ 5, 4,
{
{ { "/A" }, 3 },
{ { "/B" }, 2 },
{ { "/C" }, 3 },
}, { "/C" }
},
// RF=7, 3 locations, 7 tables, 10 (3 + 4 + 3) tablet servers.
{ 7, 7,
{
{ { "/A" }, 3 },
{ { "/B" }, 4 },
{ { "/C" }, 3 },
}, { "/C" }
},
// RF=2, 4 locations, 4 (1 + 2 + 1) tablet servers.
{ 2, 3,
{
{ { "/A" }, 1 },
{ { "/B" }, 2 },
{ { "/C" }, 1 },
}, { "/B" }
},
// RF=4, 4 locations, 6 (3 + 1 + 1 + 1) tablet servers.
{ 4, 8,
{
{ { "/A" }, 3 },
{ { "/B" }, 1 },
{ { "/C" }, 1 },
{ { "/D" }, 1 },
}, { "/B", "/D" }
},
};
// Custom name generator for LA rebalancing scenarios described by
// LaRebalancingParams.
static string LaRebalancingTestName(
const testing::TestParamInfo<LaRebalancingParams>& info) {
ostringstream str;
const auto& p = info.param;
str << "idx" << info.index
<< "_rf" << p.replication_factor
<< "_t" << p.tables_num
<< "_l";
for (const auto& elem : p.location_info) {
str << "_" << elem.second;
}
return str.str();
}
// This is used by 'operator<<(ostream&, const LaRebalancingParams&)' below.
ostream& operator <<(ostream& out, const LocationInfo& info) {
out << "{ ";
for (const auto& elem : info) {
out << elem.first << ":" << elem.second << " ";
}
out << "}";
return out;
}
// This is useful to print the configuration of a failed param test.
ostream& operator <<(ostream& out, const LaRebalancingParams& info) {
out << "{ rep_factor: " << info.replication_factor;
out << ", num_tables: " << info.tables_num
<< ", location_info: ";
out << info.location_info;
out << " }";
return out;
}
class LocationAwareRebalancingParamTest :
public RebalancingTest,
public ::testing::WithParamInterface<LaRebalancingParams> {
public:
LocationAwareRebalancingParamTest()
: RebalancingTest(GetParam().tables_num,
GetParam().replication_factor,
std::accumulate(GetParam().location_info.begin(),
GetParam().location_info.end(), 0,
[](int sum, const LocationInfo::value_type& e) {
return sum + e.second;
})) {
}
bool is_343_scheme() const override {
// These tests are for the 3-4-3 replica management scheme only.
return true;
}
};
INSTANTIATE_TEST_SUITE_P(, LocationAwareRebalancingParamTest,
::testing::ValuesIn(kLaRebalancingParams),
LaRebalancingTestName);
TEST_P(LocationAwareRebalancingParamTest, Rebalance) {
SKIP_IF_SLOW_NOT_ALLOWED();
const auto& param = GetParam();
const auto& location_info = param.location_info;
const auto& excluded_locations = param.excluded_locations;
const vector<string>& extra_master_flags = {
// In this test, the only users of the location assignment test script
// are the tablet servers: at this sub-class level it's hard to control
// when the test client connects to the external minicluster.
"--master_client_location_assignment_enabled=false",
// This test can exercise scenarios with even replication factor for tables.
"--allow_unsafe_replication_factor",
};
NO_FATALS(Prepare({}, extra_master_flags, location_info, excluded_locations));
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--output_replica_distribution_details=true",
};
// The run of the location-aware rebalancing tool should report the cluster
// as balanced.
{
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
if (!param.excluded_locations.empty()) {
// In all location-aware cluster configurations where the replica were
// initially placed everywhere but some 'excluded locations', the cluster
// was unbalanced, so some replicas should have been moved.
ASSERT_STR_NOT_CONTAINS(out, "(moved 0 replicas)");
}
if (param.replication_factor == 2 || param.location_info.size() == 2 ||
(param.location_info.size() == 3 && param.replication_factor == 4)) {
// In case some cases it's impossible to satisfy the placement policy's
// constraints.
ASSERT_STR_CONTAINS(out, "Placement policy violations:\n");
ASSERT_STR_CONTAINS(out,
"Number of non-complying tables | Number of non-complying tablets\n")
<< "stderr: " << err;
// The "--output_replica_distribution_details" flag is set: the tool
// should output details on the violations of the placement policy.
ASSERT_STR_CONTAINS(out, "Placement policy violation details:\n")
<< "stderr: " << err;
} else if (param.location_info.size() > 1) {
// In other cases all the violations of the placement policy should be
// corrected (in the case of a single location the rebalancer does not
// check against placement policy violations because that case is treated
// the same as a location-unaware, whole cluster rebalancing).
ASSERT_STR_CONTAINS(out, "Placement policy violations:\n none\n");
}
}
}
// Regression test for KUDU-3346.
TEST_P(LocationAwareRebalancingParamTest, RebalanceWithIgnoredTServer) {
SKIP_IF_SLOW_NOT_ALLOWED();
const auto& param = GetParam();
const auto& location_info = param.location_info;
const auto& excluded_locations = param.excluded_locations;
const vector<string>& extra_master_flags = {
"--master_client_location_assignment_enabled=false",
"--allow_unsafe_replication_factor",
};
NO_FATALS(Prepare({}, extra_master_flags, location_info, excluded_locations));
// Pick a random tserver as ignored tserver.
int rand_ts_idx = rand() % cluster_->num_tablet_servers();
string rand_ts_uuid = cluster_->tablet_server(rand_ts_idx)->uuid();
{
string out;
string err;
const Status s = RunKuduTool({"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + rand_ts_uuid},
&out,
&err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_NOT_CONTAINS(out, rand_ts_uuid);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced") << "stderr: " << err;
}
{
// Run rebalancer tool with 'move_replicas_from_ignored_tservers'.
string out;
string err;
Status s = RunKuduTool({"tserver",
"state",
"enter_maintenance",
cluster_->master()->bound_rpc_addr().ToString(),
rand_ts_uuid},
&out,
&err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
s = RunKuduTool({"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--ignored_tservers=" + rand_ts_uuid,
"--move_replicas_from_ignored_tservers"},
&out,
&err);
if (s.ok()) {
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced") << "stderr: " << err;
ASSERT_STR_CONTAINS(out, Substitute("$0 | 0", rand_ts_uuid)) << "stderr: " << err;
} else {
// In some cases it's impossible to move replicas from a ignored tserver.
ASSERT_STR_CONTAINS(err, "Too many ignored tservers") << "stderr: " << err;
}
}
}
// Basic intra location rebalance tests.
class IntraLocationRebalancingBasicTest : public RebalancingTest {
public:
IntraLocationRebalancingBasicTest()
: RebalancingTest(/*num_tables=*/ 1,
/*rep_factor=*/ 3,
/*num_tservers=*/ 11) {
}
bool is_343_scheme() const override {
return true;
}
};
TEST_F(IntraLocationRebalancingBasicTest, LocationsWithEmptyTabletServers) {
SKIP_IF_SLOW_NOT_ALLOWED();
const string first_table_name_pattern = "rebalance_test_first_table_$0";
const string second_table_name_pattern = "rebalance_test_second_table_$0";
const LocationInfo location_info = { { "/A", 3 }, { "/B", 3 }, { "/C", 3 },
{ "/D", 2 } };
const vector<string>& extra_master_flags = {
"--master_client_location_assignment_enabled=false",
};
copy(extra_master_flags.begin(), extra_master_flags.end(),
back_inserter(master_flags_));
FLAGS_num_tablet_servers = num_tservers_;
FLAGS_num_replicas = rep_factor_;
NO_FATALS(BuildAndStart(tserver_flags_, master_flags_, location_info,
/*create_table=*/ false));
// Create special intra location imbalance in location "/D". Location "/D"
// should only contain tablet replicas of one table.
//
// Note: there are 3 tablets in each table and the replica factor is 3,
// so it's 9 tablet replicas per table.
//
// 1. Create table0 with tablet replicas in locations /A, /B and /C. Because
// the per table location load skew is not greater than 1, it won't trigger
// cross location rebalance, so no replica of table0 will be moved.
ASSERT_OK(CreateTablesExcludingLocations({"/D"}, first_table_name_pattern));
// 2. Create table1 in { "/A", 3 }, { "/B", 3 }, { "/C", 3 }, {"/D", 1 }.
// There is an imbalance in location "/D" of table1.
ASSERT_OK(CreateTablesExcludingTserversInLocations({ {"/D", 1 } },
second_table_name_pattern));
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
};
// Before the fix added in this changelist the rebalancer would simply
// crash while running. See KUDU-2987 for detail informations.
{
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
// Intra location rebalancing in location "/D" should move one replica
// to another tserver, so there is at least one move.
ASSERT_STR_NOT_CONTAINS(out, "(moved 0 replicas)");
ASSERT_STR_CONTAINS(out, "Placement policy violations:\n none\n");
}
}
class TableRangeRebalancingTest : public RebalancingTest {
public:
TableRangeRebalancingTest()
: RebalancingTest(/*num_tables=*/ 1,
/*rep_factor*/ 3,
/*num_tservers*/ 3) {
}
bool is_343_scheme() const override {
return true;
}
int num_hash_partitions_for_test_tables() const override {
return 8;
}
int num_range_partitions_for_test_tables() const override {
return 2;
}
};
TEST_F(TableRangeRebalancingTest, Basic) {
SKIP_IF_SLOW_NOT_ALLOWED();
constexpr const char kPerServerReferenceOutput[] =
R"***(Per-server replica distribution summary:
Statistic | Value
-----------------------+-----------
Minimum Replica Count | 16
Maximum Replica Count | 16
Average Replica Count | 16)***";
constexpr const char kReplicaDistributionReferenceOutput[] =
R"***(Per-table replica distribution summary:
Replica Skew | Value
--------------+----------
Minimum | 0
Maximum | 0
Average | 0)***";
// There should be 8 tablet replicas for a particular range per tablet server.
constexpr const char kFirstRangeReferencePattern[] =
"Range start key: '00000000'\n.+\n.+\n .+ 8\n .+ 8\n .+ 8\n";
constexpr const char kSecondRangeReferencePattern[] =
"Range start key: 'ff80000000'\n.+\n.+\n .+ 8\n .+ 8\n .+ 8\n";
vector<string> table_names;
NO_FATALS(Prepare({}, {}, {}, kEmptySet, &table_names));
ASSERT_EQ(1, table_names.size());
{
const vector<string> tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--enable_range_rebalancing",
Substitute("--tables=$0", table_names.front()),
};
string out;
string err;
const Status s = RunKuduTool(tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, "rebalancing is complete: cluster is balanced")
<< "stderr: " << err;
}
{
const vector<string> report_tool_args = {
"cluster",
"rebalance",
cluster_->master()->bound_rpc_addr().ToString(),
"--enable_range_rebalancing",
Substitute("--tables=$0", table_names.front()),
"--report_only",
"--output_replica_distribution_details",
};
string out;
string err;
const Status s = RunKuduTool(report_tool_args, &out, &err);
ASSERT_TRUE(s.ok()) << ToolRunInfo(s, out, err);
ASSERT_STR_CONTAINS(out, kPerServerReferenceOutput);
ASSERT_STR_CONTAINS(out, kReplicaDistributionReferenceOutput);
ASSERT_STR_MATCHES(out, kFirstRangeReferencePattern);
ASSERT_STR_MATCHES(out, kSecondRangeReferencePattern);
}
}
} // namespace tools
} // namespace kudu