org.apache.storm.networktopography

Interface DNSToSwitchMapping

All Known Implementing Classes:

AbstractDNSToSwitchMapping, AlternateRackDNSToSwitchMapping, DefaultRackDNSToSwitchMapping

public interface DNSToSwitchMapping

An interface that must be implemented to allow pluggable DNS-name/IP-address to RackID resolvers.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_RACK

Method Summary

Modifier and Type	Method and Description
Map<String,String>	resolve(List<String> names) Resolves a list of DNS-names/IP-address and returns back a map of DNS-name->switch information ( network paths).

Field Detail

DEFAULT_RACK

static final String DEFAULT_RACK

See Also:

Constant Field Values

Method Detail

resolve

Map<String,String> resolve(List<String> names)

Resolves a list of DNS-names/IP-address and returns back a map of DNS-name->switch information ( network paths). 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 {DEFAULT_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:

Map of hosts to resolved network paths. If names is empty, then return empty Map