Examples with ProtocolHandler org.apache.nifi.cluster.protocol.ProtocolHandler used on opensource projects

Example 1 with ProtocolHandler

use of org.apache.nifi.cluster.protocol.ProtocolHandler in project nifi by apache.

the class SocketProtocolListener method dispatchRequest.

@Override
public void dispatchRequest(final Socket socket) {
    String hostname = null;
    try {
        final StopWatch stopWatch = new StopWatch(true);
        hostname = socket.getInetAddress().getHostName();
        final String requestId = UUID.randomUUID().toString();
        logger.debug("Received request {} from {}", requestId, hostname);
        String requestorDn = getRequestorDN(socket);
        // unmarshall message
        final ProtocolMessageUnmarshaller<ProtocolMessage> unmarshaller = protocolContext.createUnmarshaller();
        final ByteCountingInputStream countingIn = new ByteCountingInputStream(socket.getInputStream());
        InputStream wrappedInStream = countingIn;
        if (logger.isDebugEnabled()) {
            // don't buffer more than 1 MB of the message
            final int maxMsgBuffer = 1024 * 1024;
            final CopyingInputStream copyingInputStream = new CopyingInputStream(wrappedInStream, maxMsgBuffer);
            wrappedInStream = copyingInputStream;
        }
        final ProtocolMessage request;
        try {
            request = unmarshaller.unmarshal(wrappedInStream);
        } finally {
            if (logger.isDebugEnabled() && wrappedInStream instanceof CopyingInputStream) {
                final CopyingInputStream copyingInputStream = (CopyingInputStream) wrappedInStream;
                byte[] receivedMessage = copyingInputStream.getBytesRead();
                logger.debug("Received message: " + new String(receivedMessage));
            }
        }
        request.setRequestorDN(requestorDn);
        // dispatch message to handler
        ProtocolHandler desiredHandler = null;
        final Collection<ProtocolHandler> handlers = getHandlers();
        for (final ProtocolHandler handler : handlers) {
            if (handler.canHandle(request)) {
                desiredHandler = handler;
                break;
            }
        }
        // if no handler found, throw exception; otherwise handle request
        if (desiredHandler == null) {
            logger.error("Received request of type {} but none of the following Protocol Handlers were able to process the request: {}", request.getType(), handlers);
            throw new ProtocolException("No handler assigned to handle message type: " + request.getType());
        } else {
            final ProtocolMessage response = desiredHandler.handle(request);
            if (response != null) {
                try {
                    logger.debug("Sending response for request {}", requestId);
                    // marshal message to output stream
                    final ProtocolMessageMarshaller<ProtocolMessage> marshaller = protocolContext.createMarshaller();
                    marshaller.marshal(response, socket.getOutputStream());
                } catch (final IOException ioe) {
                    throw new ProtocolException("Failed marshalling protocol message in response to message type: " + request.getType() + " due to " + ioe, ioe);
                }
            }
        }
        stopWatch.stop();
        final NodeIdentifier nodeId = getNodeIdentifier(request);
        final String from = nodeId == null ? hostname : nodeId.toString();
        logger.info("Finished processing request {} (type={}, length={} bytes) from {} in {}", requestId, request.getType(), countingIn.getBytesRead(), from, stopWatch.getDuration());
    } catch (final IOException | ProtocolException e) {
        logger.warn("Failed processing protocol message from " + hostname + " due to " + e, e);
        if (bulletinRepository != null) {
            final Bulletin bulletin = BulletinFactory.createBulletin("Clustering", "WARNING", String.format("Failed to process protocol message from %s due to: %s", hostname, e.toString()));
            bulletinRepository.addBulletin(bulletin);
        }
    }
}