Package io.netty.resolver.dns

Enum DnsNameResolverChannelStrategy

java.lang.Object

java.lang.Enum<DnsNameResolverChannelStrategy>

io.netty.resolver.dns.DnsNameResolverChannelStrategy

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<DnsNameResolverChannelStrategy>

public enum DnsNameResolverChannelStrategy
extends java.lang.Enum<DnsNameResolverChannelStrategy>

Strategy that influence how Channels are used during queries.

Enum Constant Summary

Enum Constants

Enum Constant	Description
ChannelPerResolution	Use a new Channel per resolution or per explicit query.
ChannelPerResolver	Use the same underlying Channel for all queries produced by a single DnsNameResolver instance.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	DnsNameResolverChannelStrategy()

Method Summary

Modifier and Type	Method	Description
static DnsNameResolverChannelStrategy	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static DnsNameResolverChannelStrategy[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ChannelPerResolver

public static final DnsNameResolverChannelStrategy ChannelPerResolver

Use the same underlying Channel for all queries produced by a single DnsNameResolver instance.

As the same Channel is used for all queries we will also use the same source port for all of these. To minimize the risk of spoofing integrators should ideally use multiple resolvers randomly, so that there is source port randomization following the recommendations of RFC5452 Section 9.2.

ChannelPerResolution

public static final DnsNameResolverChannelStrategy ChannelPerResolution

Use a new Channel per resolution or per explicit query. As of today this is similar to what the DefaultNameResolver (JDK default) does. As we will need to open and close a new socket for each resolution it will come with a performance overhead. That said using this strategy should be the most robust and also guard against problems that can arise in kubernetes (or similar) setups.

Constructor Detail

DnsNameResolverChannelStrategy

private DnsNameResolverChannelStrategy()

Method Detail

values

public static DnsNameResolverChannelStrategy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (DnsNameResolverChannelStrategy c : DnsNameResolverChannelStrategy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static DnsNameResolverChannelStrategy valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null