alluxio

Class Registry<T extends Server<U>,U>

java.lang.Object

alluxio.Registry<T,U>

Type Parameters:

T - the type of the Server

U - the type of the Server.start(T) method options

Direct Known Subclasses:

MasterRegistry, WorkerRegistry

@ThreadSafe
public class Registry<T extends Server<U>,U>
extends Object

Class for registering individual Servers that run within an Alluxio process. The intended use of this class is for the Alluxio process to register the individual Servers using an instance of this class. The registry is passed as an argument to constructors of individual Servers who are expected to add themselves to the registry. The reason for using an instance as opposed to a static class is to enable dependency injection in tests.

Constructor Summary

Constructors

Constructor and Description
Registry() Creates a new instance of Registry.

Method Summary

Modifier and Type	Method and Description
<W extends T> void	add(Class<W> clazz, T server)
void	close() Closes all Servers in reverse dependency order.
<W extends T> W	get(Class<W> clazz) Convenience method for calling get(Class, int) with a default timeout.
<W extends T> W	get(Class<W> clazz, int timeoutMs) Attempts to look up the Server for the given class.
List<T>	getServers()
void	start(U options) Starts all Servers in dependency order.
void	stop() Stops all Servers in reverse dependency order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Registry

public Registry()

Creates a new instance of Registry.

Method Detail

get

public <W extends T> W get(Class<W> clazz)

Convenience method for calling get(Class, int) with a default timeout.

Type Parameters:

W - the type of the Server to get

Parameters:

clazz - the class of the Server to get

Returns:

the Server instance

get

public <W extends T> W get(Class<W> clazz,
                           int timeoutMs)

Attempts to look up the Server for the given class. Because Servers can be looked up and added to the registry in parallel, the lookup is retried until the given timeout period has elapsed.

Type Parameters:

W - the type of the Server to get

Parameters:

clazz - the class of the Server to get

timeoutMs - timeout for looking up the server

Returns:

the Server instance

add

public <W extends T> void add(Class<W> clazz,
                              T server)

Type Parameters:

W - the type of the Server to add

Parameters:

clazz - the class of the Server to add

server - the Server to add

getServers

public List<T> getServers()

Returns:

a list of all the registered Servers, order by dependency relation

start

public void start(U options)
           throws IOException

Starts all Servers in dependency order. If A depends on B, A is started before B. If a Server fails to start, already-started Servers will be stopped.

Parameters:

options - the start options

Throws:

IOException

stop

public void stop()
          throws IOException

Stops all Servers in reverse dependency order. If A depends on B, A is stopped before B.

Throws:

IOException

close

public void close()
           throws IOException

Closes all Servers in reverse dependency order. If A depends on B, A is closed before B.

Throws:

IOException