6d80c641e9
Motivation: If there are multiple DNS servers to query Java's DNS resolver will attempt to resolve A and AAAA records in sequential order and will terminate with a failure once all DNS servers have been exhausted. Netty's DNS server will share the same DnsServerAddressStream for the different record types which may send the A question to the first host and the AAAA question to the second host. Netty's DNS resolution also may not progress to the next DNS server in all situations and doesn't have a means to know when resolution has completed. Modifications: - DnsServerAddressStream should support new methods to allow the same stream to be used to issue multiple queries (e.g. A and AAAA) against the same host. - DnsServerAddressStream should support a method to determine when the stream will start to repeat, and therefore a failure can be returned. - Introduce SequentialDnsServerAddressStreamProvider for sequential use cases Result: Fixes https://github.com/netty/netty/issues/6926.
47 lines
1.7 KiB
Java
47 lines
1.7 KiB
Java
/*
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* Copyright 2017 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.resolver.dns;
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import io.netty.util.internal.UnstableApi;
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import java.net.InetSocketAddress;
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import static io.netty.resolver.dns.DnsServerAddresses.sequential;
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/**
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* A {@link DnsServerAddressStreamProvider} which is backed by a sequential list of DNS servers.
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*/
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@UnstableApi
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public final class SequentialDnsServerAddressStreamProvider extends UniSequentialDnsServerAddressStreamProvider {
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/**
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* Create a new instance.
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* @param addresses The addresses which will be be returned in sequential order via
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* {@link #nameServerAddressStream(String)}
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*/
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public SequentialDnsServerAddressStreamProvider(InetSocketAddress... addresses) {
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super(sequential(addresses));
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}
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/**
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* Create a new instance.
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* @param addresses The addresses which will be be returned in sequential order via
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* {@link #nameServerAddressStream(String)}
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*/
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public SequentialDnsServerAddressStreamProvider(Iterable<? extends InetSocketAddress> addresses) {
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super(sequential(addresses));
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}
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}
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