[CONF] Apache Qpid > Current and proposed network interfaces

[confluence]

Current and proposed network interfaces Page edited by Aidan Skinner Purpose This design page describes the low level design for the new interface which is aimed at facilitating encapsulation for the Network code in both the Java Broker & Client. This is the first step in decoupling the exsiting IO layer from both the surrounding Qpid code and more specifically from the current tie-in to MINA. This document will provide sufficient information for architecture review and also for input to task breakdown & planning. Interface Requirements Provide an API which supports pluggable network layers Facilitate the replacement of instantiations of MINA classes with an abstraction Network interface and drivers should be thread model agnostic. The Ability to set TCP options (see main design doc for details) Provide support for configuration of related properties including buffer size The interface will support an SSLEngine Current design For details on the current implementation see Current Architecture New Design NetworkDriver takes bytes from the network and passes them to the ProtocolEngine. It also accepts bytes from the ProtocolEngine and writes them to the network. ProtocolEngine accepts bytes from the NetworkDriver and turns them into AMQFrames for processing. It accepts frames and encodes them into bytes which it then hands off to the NetworkDriver. Design choices Initial designs will only support TCP (see main design doc for info) The NetworkDriver.send() method will not block, and neither will the ProtcolEngine.received(). As soon as they have stored the data for later processing they will return. New broker network / protocol engine interface New client network / protocol engine interface In the new version, a NetworkDriver is created by a ProtocolEngine (in the case of outgoing conenctions) or by the Broker at startup and creates a ProtocolEngine when new connections are created. The network driver passes raw data to the ProtocolEngine which is responsible for both decoding the frames and processing them. When the ProtocolEngine wishes to send data, it does so by calling the NetworkDriver. The existing mechanisms for frame listeners etc are retained, but are decoupled from the network processing parts. At the start of a connection the the NetworkDriver will pass data to a ProtocolEngine which will handle protocol negotiation and return the ProtocolEngine to use or throw an exception if no driver is available. The implementation will use the existing Sender and Reciever interfaces in org.apache.qpid.transport which will allow the use of the existing alternate transport layer implementations. The thread of control remains with the network driver. Data comes in from the operating system, is read from the socket by the NetworkDriver and given to the ProtocolEngines received method. The ProtocolEngine is responsible for processing the bytes and interfacing to the rest of the broker or client. The ProtocolEngine will write bytes to the wire using the NetworkDriver which implements the existing Sender interface from org.apache.qpid.transport Sender (already exists): /** * This interface is implemented by things which accept data for sending to a remote end point */ public interface Sender<T> { // Sets the TCP idle time out void setIdleTimeout(long l); // Accepts the data for sending void send(T msg); // Flushes all data pending void flush(); // Closes the connection void close(); } The ProtocolEngine will implement the Reciever interface to be given bytes by the NetworkDriver in it's received method. Receiever (already exists): /** * This interface is implemented by things which accept data for processing */ public interface Receiver<T> { // Called when data has been received from the network void received(T msg); // Called when an exception has occured void exception(Throwable t); // Called when the underlying socket has been closed for reading void closed(); } The ProtocolEngine will implement the following interface: /** * A ProtocolEngine is a Receiver for java.nio.ByteBuffers. It takes the data passed to it in the received * decodes it and then process the result. */ public interface ProtocolEngine extends Receiver<java.nio.ByteBuffer> { // Sets the network driver providing data for this ProtocolEngine void setNetworkDriver (NetworkDriver driver) // Returns the remote address of the NetworkDriver void SocketAddress getRemoteAddress() // Returns number of bytes written long getWrittenBytes() // Returns number of bytes read long getReadBytes() // Called by the NetworkDriver when the socket has been closed for reading void closed() // Called when the NetworkEngine has not written data for the specified period of time (will trigger a // heartbeat) void writerIdle() // Called when the NetworkEngine has not read data for the specified period of time (will close the connection) void readerIdle() /** * Accepts an AMQFrame for writing to the network. The ProtocolEngine encodes the frame into bytes and * passes the data onto the NetworkDriver for sending */ void writeFrame(AMQDataBlock frame) } public interface ProtocolEngineFactory { // Returns a new instance of a ProtocolEngine ProtocolEngine newProtocolEngine() } The NetworkDriver will implement the following interface: public interface NetworkDriver extends Sender<java.nio.ByteBuffer> { // Creates a NetworkDriver which attempts to connect to destination on port and attaches the ProtocolEngine to // it using the SSLEngine if provided static NetworkDriver open(int port, InetAddress destination, ProtocolEngine engine, NetworkDriverConfiguration config, SSLEngine engine) throws OpenException; // listens for incoming connections on the specified ports and address and creates a new NetworkDriver which // processes incoming connections with ProtocolEngines created from factory using the SSLEngine if provided static void bind (int port, InetAddress[] addresses, ProtocolEngineFactory factory, NetworkDriverConfiguration config, SSLEngine engine) throws BindException; // Returns the remote address of underlying socket void SocketAddress getRemoteAddress() /** * The length of time after which the ProtocolEngines readIdle() method should be called if no data has been * read */ void setMaxReadIdle(int idleTime) /** * The length of time after which the ProtocolEngines writeIdle() method should be called if no data has been * written */ void setMaxWriteIdle(int idleTime) } The NetworkConfiguration interface provides configuration data for the NetworkDriver: public interface NetworkDriverConfiguration { // Taken from Socket boolean getKeepAlive() boolean getOOBInline() boolean getReuseAddress() Integer getSoLinger() // null means off int getSoTimeout() boolean getTcpNoDelay() int getTrafficClass() // The amount of memory in bytes to allocate to the incoming buffer int getReceiveBufferSize(); // The amount of memory in bytes to allocate to the outgoing buffer int getSendBufferSize(int size); } Change Notification Preferences View Online | View Change | Add Comment --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:commits-subscr...@qpid.apache.org