Interface DNSToSwitchMapping

All Known Implementing Classes:
AbstractDNSToSwitchMapping, CachedDNSToSwitchMapping, ScriptBasedMapping, TopologyAwareEnsemblePlacementPolicy.DefaultResolver, TopologyAwareEnsemblePlacementPolicy.DNSResolverDecorator

@Beta public interface DNSToSwitchMapping
An interface that must be implemented to allow pluggable DNS-name/IP-address to RackID resolvers.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Reload all of the cached mappings.
    Resolves a list of DNS-names/IP-addresses and returns back a list of switch information (network paths).
    default void
    Receives the current BookieAddressResolver.
    default boolean
    Hints what to use with implementation when InetSocketAddress is converted to String: hostname (addr.getHostName(), default) or IP address (addr.getAddress().getHostAddress()).
  • Method Details

    • resolve

      List<String> resolve(List<String> names)
      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 NetworkTopology.DEFAULT_REGION_AND_RACK. This is what the bundled implementations do, though it is not a formal requirement

      Parameters:
      names - the list of hosts to resolve (can be empty)
      Returns:
      list of resolved network paths. If names is empty, the returned list is also empty
    • reloadCachedMappings

      void reloadCachedMappings()
      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.

    • useHostName

      default boolean useHostName()
      Hints what to use with implementation when InetSocketAddress is converted to String: hostname (addr.getHostName(), default) or IP address (addr.getAddress().getHostAddress()).
      Returns:
      true if hostname, false if IP address. Default is true.
    • setBookieAddressResolver

      default void setBookieAddressResolver(BookieAddressResolver bookieAddressResolver)
      Receives the current BookieAddressResolver.
      Parameters:
      bookieAddressResolver -