| // 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 "kudu/util/net/dns_resolver.h" |
| |
| #include <cstdint> |
| #include <cstdlib> |
| #include <ostream> |
| #include <string> |
| #include <thread> |
| #include <vector> |
| |
| #include <gflags/gflags.h> |
| #include <glog/logging.h> |
| #include <gtest/gtest.h> |
| |
| #include "kudu/gutil/macros.h" |
| #include "kudu/gutil/strings/substitute.h" |
| #include "kudu/gutil/strings/util.h" |
| #include "kudu/util/async_util.h" |
| #include "kudu/util/monotime.h" |
| #include "kudu/util/net/net_util.h" |
| #include "kudu/util/net/sockaddr.h" |
| #include "kudu/util/scoped_cleanup.h" |
| #include "kudu/util/test_macros.h" |
| |
| DECLARE_string(dns_addr_resolution_override); |
| DECLARE_uint32(dns_resolver_cache_capacity_mb); |
| |
| using std::thread; |
| using std::vector; |
| using strings::Substitute; |
| |
| namespace kudu { |
| |
| TEST(DnsResolverTest, AsyncResolution) { |
| vector<Sockaddr> addrs; |
| // Non-caching asynchronous DNS resolver. |
| DnsResolver resolver(1/* max_threads_num */); |
| Synchronizer s; |
| resolver.ResolveAddressesAsync(HostPort("localhost", 12345), &addrs, |
| s.AsStatusCallback()); |
| ASSERT_OK(s.Wait()); |
| ASSERT_TRUE(!addrs.empty()); |
| for (const Sockaddr& addr : addrs) { |
| LOG(INFO) << "Address: " << addr.ToString(); |
| EXPECT_TRUE(HasPrefixString(addr.ToString(), "127.")); |
| EXPECT_TRUE(HasSuffixString(addr.ToString(), ":12345")); |
| } |
| } |
| |
| TEST(DnsResolverTest, RefreshCachedEntry) { |
| gflags::FlagSaver saver; |
| vector<Sockaddr> addrs; |
| DnsResolver resolver(1/* max_threads_num */, 1024 * 1024/* cache_capacity_bytes */); |
| ASSERT_OK(resolver.ResolveAddresses(HostPort("localhost", 12345), &addrs)); |
| ASSERT_TRUE(!addrs.empty()); |
| for (const Sockaddr& addr : addrs) { |
| LOG(INFO) << "Address: " << addr.ToString(); |
| EXPECT_TRUE(HasPrefixString(addr.ToString(), "127.")); |
| EXPECT_TRUE(HasSuffixString(addr.ToString(), ":12345")); |
| } |
| // If we override the DNS lookup address, when we refresh the address, the |
| // cached entry gets reset. |
| constexpr const char* kFakeAddr = "1.1.1.1"; |
| FLAGS_dns_addr_resolution_override = Substitute("localhost=$0", kFakeAddr); |
| Synchronizer s; |
| resolver.RefreshAddressesAsync(HostPort("localhost", 1111), &addrs, |
| s.AsStatusCallback()); |
| ASSERT_OK(s.Wait()); |
| ASSERT_EQ(1, addrs.size()); |
| ASSERT_EQ(Substitute("$0:1111", kFakeAddr), addrs[0].ToString()); |
| ASSERT_EQ(1111, addrs[0].port()); |
| |
| // Once we stop overriding DNS lookups, simply getting the address from the |
| // resolver will read from the cache. |
| FLAGS_dns_addr_resolution_override = ""; |
| ASSERT_OK(resolver.ResolveAddresses(HostPort("localhost", 12345), &addrs)); |
| ASSERT_EQ(1, addrs.size()); |
| ASSERT_EQ(Substitute("$0:12345", kFakeAddr), addrs[0].ToString()); |
| ASSERT_EQ(12345, addrs[0].port()); |
| |
| // But a refresh should return the original address. |
| Synchronizer s2; |
| resolver.RefreshAddressesAsync(HostPort("localhost", 12345), &addrs, |
| s2.AsStatusCallback()); |
| ASSERT_OK(s2.Wait()); |
| EXPECT_FALSE(addrs.empty()); |
| for (const Sockaddr& addr : addrs) { |
| LOG(INFO) << "Address: " << addr.ToString(); |
| EXPECT_TRUE(HasPrefixString(addr.ToString(), "127.")); |
| EXPECT_TRUE(HasSuffixString(addr.ToString(), ":12345")); |
| } |
| } |
| |
| TEST(DnsResolverTest, ConcurrentRefreshesAndResolutions) { |
| constexpr int kNumThreads = 3; |
| constexpr int kNumResolutionsPerThread = 10; |
| DnsResolver resolver(1/* max_threads_num */, 1024 * 1024/* cache_capacity_bytes */); |
| vector<thread> threads; |
| auto cancel_threads = MakeScopedCleanup([&] { |
| for (auto& t : threads) { |
| t.join(); |
| } |
| }); |
| const auto validate_addrs = [] (const vector<Sockaddr>& addrs) { |
| ASSERT_FALSE(addrs.empty()); |
| for (const Sockaddr& addr : addrs) { |
| EXPECT_TRUE(HasPrefixString(addr.ToString(), "127.")); |
| EXPECT_TRUE(HasSuffixString(addr.ToString(), ":12345")); |
| } |
| }; |
| for (int i = 0; i < kNumThreads - 1; i++) { |
| threads.emplace_back([&] { |
| for (int r = 0; r < kNumResolutionsPerThread; r++) { |
| vector<Sockaddr> addrs; |
| Synchronizer s; |
| resolver.RefreshAddressesAsync(HostPort("localhost", 12345), &addrs, |
| s.AsStatusCallback()); |
| ASSERT_OK(s.Wait()); |
| NO_FATALS(validate_addrs(addrs)); |
| } |
| }); |
| } |
| threads.emplace_back([&] { |
| for (int r = 0; r < kNumResolutionsPerThread; r++) { |
| vector<Sockaddr> addrs; |
| ASSERT_OK(resolver.ResolveAddresses(HostPort("localhost", 12345), &addrs)); |
| NO_FATALS(validate_addrs(addrs)); |
| } |
| }); |
| for (auto& t : threads) { |
| t.join(); |
| } |
| cancel_threads.cancel(); |
| } |
| |
| TEST(DnsResolverTest, CachingVsNonCachingResolver) { |
| constexpr const auto kNumIterations = 1000; |
| constexpr const auto kIdxNonCached = 0; |
| constexpr const auto kIdxCached = 1; |
| constexpr const char* const kHost = "localhost"; |
| |
| MonoDelta timings[2]; |
| for (auto idx = 0; idx < ARRAYSIZE(timings); ++idx) { |
| // DNS resolver's cache capacity of 0 means the results are not cached. |
| size_t capacity_mb = idx * 1024 * 1024; |
| DnsResolver resolver(1, capacity_mb, MonoDelta::FromSeconds(10)); |
| const auto start_time = MonoTime::Now(); |
| for (auto i = 0; i < kNumIterations; ++i) { |
| vector<Sockaddr> addrs; |
| uint16_t port = rand() % kNumIterations + kNumIterations; |
| { |
| HostPort hp(kHost, port); |
| ASSERT_OK(resolver.ResolveAddresses(hp, &addrs)); |
| } |
| ASSERT_TRUE(!addrs.empty()); |
| for (const Sockaddr& addr : addrs) { |
| EXPECT_TRUE(HasSuffixString(addr.ToString(), Substitute(":$0", port))) << addr.ToString(); |
| } |
| } |
| timings[idx] = MonoTime::Now() - start_time; |
| } |
| LOG(INFO) << Substitute("$0 non-cached resolutions of '$1' took $2", |
| kNumIterations, kHost, |
| timings[kIdxNonCached].ToString()); |
| LOG(INFO) << Substitute("$0 cached resolutions of '$1' took $2", |
| kNumIterations, kHost, |
| timings[kIdxCached].ToString()); |
| ASSERT_GT(timings[kIdxNonCached], timings[kIdxCached]); |
| } |
| |
| } // namespace kudu |