org.jgroups.protocols.pbcast

Class STATE

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.pbcast.StreamingStateTransfer

org.jgroups.protocols.pbcast.STATE

All Implemented Interfaces:

ProcessingQueue.Handler<Address>

public class STATE
extends StreamingStateTransfer

STATE streams the state (written to an OutputStream) to the state requester in chunks (defined by chunk_size). Every chunk is sent via a unicast message. The state requester writes the chunks into a blocking input stream (BlockingInputStream) from which the MessageListener.setState(java.io.InputStream) reads it. The size of the BlockingInputStream is buffer_size bytes.

When implementing MessageListener.getState(java.io.OutputStream), the state should be written in sizeable chunks, because the underlying output stream generates 1 message / write. So if there are 1000 writes of 1 byte each, this would generate 1000 messages ! We suggest using a BufferedOutputStream over the output stream handed to the application as argument of the callback.

When implementing the MessageListener.setState(java.io.InputStream) callback, there is no need to use a BufferedOutputStream, as the input stream handed to the application already buffers incoming data internally.

Since:

2.4

Author:

Bela Ban, Vladimir Blagojevic

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	STATE.StateOutputStream

Nested classes/interfaces inherited from class org.jgroups.protocols.pbcast.StreamingStateTransfer

StreamingStateTransfer.StateGetter, StreamingStateTransfer.StateHeader

Field Summary

Fields

Modifier and Type	Field and Description
protected BlockingInputStream	input_stream If use_default_transport is true, we consume bytes off of this blocking queue.

Fields inherited from class org.jgroups.protocols.pbcast.StreamingStateTransfer

avg_state_size, buffer_size, flushProtocolInStack, local_addr, max_pool, members, num_bytes_sent, num_state_reqs, pool_thread_keep_alive, state_provider, state_requesters, thread_pool

Fields inherited from class org.jgroups.stack.Protocol

after_creation_hook, down_prot, ergonomics, id, log, name, stack, stats, up_prot

Constructor Summary

Constructors

Constructor and Description
STATE()

Method Summary

Modifier and Type	Method and Description
protected Tuple<java.io.InputStream,java.lang.Object>	createStreamToProvider(Address provider, StreamingStateTransfer.StateHeader hdr) Creates an InputStream to the state provider to read the state.
protected void	createStreamToRequester(Address requester) Creates an OutputStream to the state requester to write the state
protected void	handleEOF(Address sender)
protected void	handleException(java.lang.Throwable exception)
protected void	handleStateChunk(Address sender, byte[] buffer, int offset, int length)
protected void	handleViewChange(View v)
protected boolean	useAsyncStateDelivery()

Methods inherited from class org.jgroups.protocols.pbcast.StreamingStateTransfer

close, closeBarrierAndSuspendStable, closeHoleFor, createThreadPool, destroy, determineCoordinator, down, getAverageStateSize, getNumberOfStateBytesSent, getNumberOfStateRequests, getStateFromApplication, getThreadPoolCompletedTasks, getThreadPoolSize, handle, handleConfig, handleStateReq, handleStateRsp, init, isDigestNeeded, modifyStateResponseHeader, openBarrier, openBarrierAndResumeStable, punchHoleFor, requiredDownServices, resetStats, resumeStable, sendEof, sendException, setStateInApplication, start, stop, up

Methods inherited from class org.jgroups.stack.Protocol

accept, afterCreationHook, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, printStats, providedDownServices, providedUpServices, requiredUpServices, resetStatistics, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, statsEnabled, up

Methods inherited from class java.lang.Object

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

Field Detail

input_stream

protected volatile BlockingInputStream input_stream

If use_default_transport is true, we consume bytes off of this blocking queue. Used on the state requester side only. Note that we cannot use a PipedInputStream as we have multiple writer threads pushing data into the input stream

Constructor Detail

STATE

public STATE()

Method Detail

handleViewChange

protected void handleViewChange(View v)

Overrides:

handleViewChange in class StreamingStateTransfer

handleEOF

protected void handleEOF(Address sender)

Overrides:

handleEOF in class StreamingStateTransfer

handleException

protected void handleException(java.lang.Throwable exception)

Overrides:

handleException in class StreamingStateTransfer

handleStateChunk

protected void handleStateChunk(Address sender,
                                byte[] buffer,
                                int offset,
                                int length)

Overrides:

handleStateChunk in class StreamingStateTransfer

createStreamToRequester

protected void createStreamToRequester(Address requester)

Description copied from class: StreamingStateTransfer

Creates an OutputStream to the state requester to write the state

Overrides:

createStreamToRequester in class StreamingStateTransfer

createStreamToProvider

protected Tuple<java.io.InputStream,java.lang.Object> createStreamToProvider(Address provider,
                                                                             StreamingStateTransfer.StateHeader hdr)

Description copied from class: StreamingStateTransfer

Creates an InputStream to the state provider to read the state. Return the input stream and a handback object as a tuple. The handback object is handed back to the subclass when done, or in case of an error (e.g. to clean up resources)

Specified by:

createStreamToProvider in class StreamingStateTransfer

useAsyncStateDelivery

protected boolean useAsyncStateDelivery()

Overrides:

useAsyncStateDelivery in class StreamingStateTransfer