fabric.dissemination.pastry

Class Disseminator

java.lang.Object

fabric.dissemination.pastry.Disseminator

public class Disseminator
extends java.lang.Object

A pastry application that implements the functionality of a Fabric dissemination network based on the beehive replication protocol.

Field Summary

Fields

Modifier and Type	Field and Description
protected long	AGGREGATION_INTERVAL Aggregation interval, in milliseconds.
protected int	baseBits
protected Cache	cache The cache of fetched objects.
protected MessageDeserializer	deserializer
protected Endpoint	endpoint The pastry endpoint.
protected int	idDigits
protected IdFactory	idf The pastry id generating factory.
protected PastryNode	node The pastry node.
protected Cache<Id,Fetch>	outstandingFetches Outstanding fetch messages awaiting replies.
protected java.util.Random	rand Random source for random ids.
protected long	REPLICATION_INTERVAL Replication interval, in milliseconds.

Constructor Summary

Constructors

Constructor and Description
Disseminator(PastryNode node, Cache cache) Creates a disseminator attached to the given pastry node.

Method Summary

Modifier and Type	Method and Description
void	aggregateInterval() Called once every aggregation interval.
void	deliver(Id id, Message msg)
void	fetch(Fetch.Reply msg) Process a Fetch.Reply message.
void	fetch(Fetch msg) Process the Fetch message.
ObjectGlob	fetch(RemoteStore c, long onum) Called by a FetchManager to fetch the specified object.
boolean	forward(RouteMessage message)
protected NodeHandle	localHandle() The NodeHandle of this pastry node.
void	replicate(Replicate.Reply msg) Processes a Replicate.Reply message, and adds objects in the reply to the cache.
void	replicate(Replicate msg) Processes a Replicate message.
void	replicateInterval() Called once every replicate interval.
protected void	reply(Cache.Entry entry, Fetch msg) Helper function.
protected void	route(Id id, Message message, NodeHandle hint) Routes a message on the pastry ring.
void	update(NodeHandle handle, boolean joined)
void	updateCache(AbstractUpdate.Reply msg) Processes the given UpdateCache.Reply message.
<UpdateType extends FastSerializable> void	updateCache(AbstractUpdate<UpdateType> msg) Processes the given UpdateCache message.

Methods inherited from class java.lang.Object

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

Field Detail

node

protected final PastryNode node

The pastry node.

endpoint

protected final Endpoint endpoint

The pastry endpoint.

idf

protected final IdFactory idf

The pastry id generating factory.

idDigits

protected final int idDigits

baseBits

protected final int baseBits

rand

protected final java.util.Random rand

Random source for random ids.

cache

protected final Cache cache

The cache of fetched objects.

outstandingFetches

protected final Cache<Id,Fetch> outstandingFetches

Outstanding fetch messages awaiting replies.

deserializer

protected final MessageDeserializer deserializer

REPLICATION_INTERVAL

protected long REPLICATION_INTERVAL

Replication interval, in milliseconds.

AGGREGATION_INTERVAL

protected long AGGREGATION_INTERVAL

Aggregation interval, in milliseconds.

Constructor Detail

Disseminator

public Disseminator(PastryNode node,
                    Cache cache)

Creates a disseminator attached to the given pastry node.

Parameters:

node - PastryNode where the disseminator is to run.

Method Detail

route

protected void route(Id id,
                     Message message,
                     NodeHandle hint)

Routes a message on the pastry ring. At least one of id or hint must be non-null.

Parameters:

id - The id of this message (hash value where it should be routed)

message - The message to be routed

hint - NodeHandle of a starting node, if desired

localHandle

protected NodeHandle localHandle()

The NodeHandle of this pastry node.

deliver

public void deliver(Id id,
                    Message msg)

fetch

public ObjectGlob fetch(RemoteStore c,
                        long onum)
                 throws DisseminationTimeoutException

Called by a FetchManager to fetch the specified object.

Throws:

DisseminationTimeoutException - if the dissemination network takes too long.

fetch

public void fetch(Fetch.Reply msg)

Process a Fetch.Reply message. Saves the glob from the reply, and returns it to the worker if it is waiting for this object.

fetch

public void fetch(Fetch msg)

Process the Fetch message. See if we have the object asked for. If so, return it to sender via a Fetch.Reply message.

reply

protected void reply(Cache.Entry entry,
                     Fetch msg)

Helper function. Reply to a Fetch message with given cache entry.

updateCache

public <UpdateType extends FastSerializable> void updateCache(AbstractUpdate<UpdateType> msg)

Processes the given UpdateCache message. Updates the local cache and forwards the update to any subscribers.

updateCache

public void updateCache(AbstractUpdate.Reply msg)

Processes the given UpdateCache.Reply message.

replicateInterval

public void replicateInterval()

Called once every replicate interval. This is the method responsible for contacting replication deciders for this node. The deciders then reply with the globs that they want to replicate to this node. This implements the pull protocol of beehive, since deciders don't know who they should replicate to, and depend on those node to contact them. When sending a replicate message, a list of globs that this node already has is sent to the decider, so that they are not sent again.

replicate

public void replicate(Replicate msg)

Processes a Replicate message. Sends back to the sender objects that should be replicated to that node.

replicate

public void replicate(Replicate.Reply msg)

Processes a Replicate.Reply message, and adds objects in the reply to the cache.

aggregateInterval

public void aggregateInterval()

Called once every aggregation interval.

forward

public boolean forward(RouteMessage message)

update

public void update(NodeHandle handle,
                   boolean joined)