Class TopologyAwareEnsemblePlacementPolicy.DNSResolverDecorator

    • Constructor Summary

      Constructors 
      Constructor Description
      DNSResolverDecorator​(DNSToSwitchMapping resolver, java.util.function.Supplier<java.lang.String> defaultRackSupplier, Counter failedToResolveNetworkLocationCounter)  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void reloadCachedMappings()
      Reload all of the cached mappings.
      java.util.List<java.lang.String> resolve​(java.util.List<java.lang.String> names)
      Resolves a list of DNS-names/IP-addresses and returns back a list of switch information (network paths).
      void setBookieAddressResolver​(BookieAddressResolver bookieAddressResolver)
      Receives the current BookieAddressResolver.
      boolean useHostName()
      Hints what to use with implementation when InetSocketAddress is converted to String: hostname (addr.getHostName(), default) or IP address (addr.getAddress().getHostAddress()).
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • defaultRackSupplier

        final java.util.function.Supplier<java.lang.String> defaultRackSupplier
      • failedToResolveNetworkLocationCounter

        @StatsDoc(name="FAILED_TO_RESOLVE_NETWORK_LOCATION_TOTAL",
                  help="total number of times Resolver failed to resolve rack information of a node")
        final Counter failedToResolveNetworkLocationCounter
    • Constructor Detail

      • DNSResolverDecorator

        DNSResolverDecorator​(DNSToSwitchMapping resolver,
                             java.util.function.Supplier<java.lang.String> defaultRackSupplier,
                             Counter failedToResolveNetworkLocationCounter)
    • Method Detail

      • resolve

        public java.util.List<java.lang.String> resolve​(java.util.List<java.lang.String> names)
        Description copied from 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 NetworkTopology.DEFAULT_REGION_AND_RACK. This is what the bundled implementations do, though it is not a formal requirement

        Specified by:
        resolve in interface DNSToSwitchMapping
        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
      • useHostName

        public boolean useHostName()
        Description copied from interface: DNSToSwitchMapping
        Hints what to use with implementation when InetSocketAddress is converted to String: hostname (addr.getHostName(), default) or IP address (addr.getAddress().getHostAddress()).
        Specified by:
        useHostName in interface DNSToSwitchMapping
        Returns:
        true if hostname, false if IP address. Default is true.
      • reloadCachedMappings

        public void reloadCachedMappings()
        Description copied from interface: DNSToSwitchMapping
        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.

        Specified by:
        reloadCachedMappings in interface DNSToSwitchMapping