org.apache.bookkeeper.net.DNSToSwitchMapping Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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*/
package org.apache.bookkeeper.net;
import com.google.common.annotations.Beta;
import java.util.List;
import org.apache.bookkeeper.proto.BookieAddressResolver;
/**
* An interface that must be implemented to allow pluggable
* DNS-name/IP-address to RackID resolvers.
*
*/
@Beta
public interface DNSToSwitchMapping {
/**
* Resolves a list of DNS-names/IP-addresses and returns back a list of
* switch information (network paths). One-to-one correspondence must be
* maintained between the elements in the lists.
* Consider an element in the argument list - x.y.com. The switch information
* that is returned must be a network path of the form /foo/rack,
* where / is the root, and 'foo' is the switch where 'rack' is connected.
* Note the hostname/ip-address is not part of the returned path.
* The network topology of the cluster would determine the number of
* components in the network path.
*
* If a name cannot be resolved to a rack, the implementation
* should return {@link NetworkTopology#DEFAULT_REGION_AND_RACK}. This
* is what the bundled implementations do, though it is not a formal requirement
*
* @param names the list of hosts to resolve (can be empty)
* @return list of resolved network paths.
* If names is empty, the returned list is also empty
*/
List resolve(List names);
/**
* Reload all of the cached mappings.
*
* If there is a cache, this method will clear it, so that future accesses
* will get a chance to see the new data.
*/
void reloadCachedMappings();
/**
* Hints what to use with implementation when InetSocketAddress is converted
* to String:
* hostname (addr.getHostName(), default)
* or IP address (addr.getAddress().getHostAddress()).
* @return true if hostname, false if IP address. Default is true.
*/
default boolean useHostName() {
return true;
}
/**
* Receives the current BookieAddressResolver.
* @param bookieAddressResolver
*/
default void setBookieAddressResolver(BookieAddressResolver bookieAddressResolver) {
}
}