users@grizzly.java.net

Re: How to implement the client's message flow based on async read/write?

From: JianXing Yi <jianxing.yi_at_gmail.com>
Date: Tue, 10 Jun 2008 10:01:02 +0800

Hi Alexey,

>
> 1. in the grizzly-based nio client, i try to establish a relatively large
> number of connections to a server, e.g. 30,000. i avoid 30s closing idle
> connections through the SelectionKeyHandler. my problem is that it seems
> that about 5,000 connections is the limit. no more connections could be
> established after that. btw, i've already adjusted the system tcp
> parameters, such as the tcp connection number (greater than 30,000) and the
> keep-alive time.
>
> It should be some system limitations, in Grizzly we don't have any. If you
> will provide me the code, I can test how many connections I can create on my
> local machine, just to compare the results.
> Also it's interesting what kind of scenario you have, which requires 30K+
> tcp connections? :))
>


> great thanks for your help!
>


> i want to generate http (may be extended) load to servers. some http
> servers can support persistent connections, so a relatively large number of
> connections to them should be established to get the performance index.
>
i compared the result of the Grizzly-based client and a raw NIO API based
> one. netstat showed the number of concurrent connections for each of them,
> they are 5k and 25k in my environment. code of the Grizzly-based client, the
> raw NIO API based client and the Grizzly-based echo server is listed below.
>


> package test.grizzly;
>
> import java.io.IOException;
> import java.net.InetSocketAddress;
> import java.net.SocketAddress;
> import java.nio.ByteBuffer;
> import java.nio.channels.SelectionKey;
> import java.util.ArrayList;
> import java.util.Iterator;
> import java.util.Queue;
> import java.util.concurrent.Callable;
> import java.util.concurrent.ConcurrentLinkedQueue;
> import java.util.concurrent.CountDownLatch;
> import java.util.concurrent.ExecutorService;
> import java.util.concurrent.Executors;
> import java.util.concurrent.atomic.AtomicLong;
>
> import com.sun.grizzly.CallbackHandler;
> import com.sun.grizzly.Context;
> import com.sun.grizzly.Controller;
> import com.sun.grizzly.ControllerStateListenerAdapter;
> import com.sun.grizzly.DefaultConnectorHandlerPool;
> import com.sun.grizzly.DefaultPipeline;
> import com.sun.grizzly.DefaultSelectionKeyHandler;
> import com.sun.grizzly.IOEvent;
> import com.sun.grizzly.Pipeline;
> import com.sun.grizzly.TCPConnectorHandler;
> import com.sun.grizzly.TCPSelectorHandler;
> import com.sun.grizzly.Controller.Protocol;
> import com.sun.grizzly.async.AsyncWriteCallbackHandler;
> import com.sun.grizzly.async.AsyncWriteQueueRecord;
>
> public class GrizzlyBasedClient {
>
> public static final int CONNECTION_NUMBER = 30000;
> public static final int NUMBER_CONNECTION_PER_THREAD = 1000;
> private static final int SERVER_PORT = 11113;
> private static final String SERVER_HOST_OR_IP = "192.168.0.113";
> private static final int CONNECTION_THREADPOOL_SIZE = 100;
> private static final int NUMBER_LOAD_ON_THREADPOOL = 10;
>
> /**
> * @param args
> * @throws InterruptedException
> * @throws IOException
> */
> public static void main(String[] args) throws InterruptedException,
> IOException {
> GrizzlyBasedClient lg = new GrizzlyBasedClient();
> lg.start();
> }
>
> private Controller controller;
> protected CountDownLatch controllerReadyLatch = new CountDownLatch(1);
> public ConcurrentLinkedQueue<TCPConnectorHandler> connectors = new
> ConcurrentLinkedQueue<TCPConnectorHandler>();
>
> // private TCPConnectorHandler connectorHandler;
>
> class MyConnectorCallbackHandler implements CallbackHandler<Context> {
> private TCPConnectorHandler tcpConnectorHandler;
>
> public MyConnectorCallbackHandler(
> TCPConnectorHandler tcpConnectorHandler) {
> this.tcpConnectorHandler = tcpConnectorHandler;
> }
>
> public void onConnect(IOEvent<Context> ioEvent) {
> try {
> tcpConnectorHandler.finishConnect(ioEvent.attachment()
> .getSelectionKey());
> allConnectedLatch.countDown();
> connectors.add(tcpConnectorHandler);
> // Reporter.getInstance().collect(
> // tcpConnectorHandler.getSelectorHandler().getPort(),
> // System.currentTimeMillis());
> connectionCount.incrementAndGet();
>
> //
> System.out.println(tcpConnectorHandler.getSelectorHandler().getPort()+",
> // "+System.currentTimeMillis());
> } catch (IOException e) {
> // System.out.println(Reporter.getInstance().verbose());
> e.printStackTrace();
> }
> }
>
> public void onRead(IOEvent<Context> arg0) {
> // TODO Auto-generated method stub
>
> }
>
> public void onWrite(IOEvent<Context> arg0) {
> // TODO Auto-generated method stub
>
> }
> }
>
> protected ByteBuffer readBuffer = ByteBuffer.allocateDirect(10240);
>
> AtomicLong transactionCount = new AtomicLong(0);
> AtomicLong connectionCount = new AtomicLong(0);
> public AtomicLong bytesRead = new AtomicLong(0);
> public AtomicLong minusOneCount = new AtomicLong(0);
> public AtomicLong zeroCount = new AtomicLong(0);
>
> class MyAsyncWriteCallbackHandler implements AsyncWriteCallbackHandler
> {
> private TCPConnectorHandler tcpConnectorHandler;
>
> public MyAsyncWriteCallbackHandler(
> TCPConnectorHandler tcpConnectorHandler) {
> this.tcpConnectorHandler = tcpConnectorHandler;
> }
>
> public void onIOException(IOException ioException, SelectionKey
> key,
> ByteBuffer buffer, Queue<AsyncWriteQueueRecord>
> remainingQueue) {
> // TODO Auto-generated method stub
>
> }
>
> public void onWriteCompleted(SelectionKey key, ByteBuffer buffer) {
> try {
>
> transactionCount.incrementAndGet();
>
> readBuffer.clear();
>
> long nCount = this.tcpConnectorHandler.read(readBuffer,
> true);
> if (nCount == -1) {
> minusOneCount.incrementAndGet();
> } else if (nCount == 0) {
> zeroCount.incrementAndGet();
> } else {
> bytesRead.addAndGet(nCount);
> }
> // readBuffer.flip();
> //
> System.out.println(Charset.defaultCharset().decode(readBuffer));
> // System.out.println("V");
> // tcpConnectorHandler.close();
> // controller.releaseConnectorHandler(tcpConnectorHandler);
> } catch (IOException e) {
> // TODO Auto-generated catch block
> e.printStackTrace();
> }
> }
> };
>
> private static int localPort = 12110;
> SocketAddress serverAddr = new InetSocketAddress(SERVER_HOST_OR_IP,
> SERVER_PORT);
> private CountDownLatch allConnectedLatch = new CountDownLatch(
> CONNECTION_NUMBER);
>
> public void start() throws InterruptedException, IOException {
> controller = createController();
> new Thread(controller).start();
> waitControllerReady();
>
> // Establish CONNECTION_NUMBER connections.
> long start1 = System.currentTimeMillis();
> for (int i = 0; i < CONNECTION_NUMBER; i++) {
> SocketAddress localAddr = new InetSocketAddress("localhost",
> localPort++);
> // connectorHandler.setLinger(10);
> TCPConnectorHandler connectorHandler = (TCPConnectorHandler)
> controller
> .acquireConnectorHandler(Protocol.TCP);
> // connectorHandler.setTcpNoDelay(true);
> connectorHandler.setReuseAddress(true);
>
> connectorHandler.connect(serverAddr, /* localAddr, */
> new MyConnectorCallbackHandler(connectorHandler));
> // Thread.sleep(20);
> }
> allConnectedLatch.await();
> long interval2 = System.currentTimeMillis() - start1;
> System.out.println("ALL CONNECTED." + " connections: "
> + connectionCount.get() + "," + connectors.size()
> + ", connection total time (s): " + interval2 / 1000);
>
> // distribute tasks
> Iterator<TCPConnectorHandler> itCon = connectors.iterator();
> ArrayList<Callable<Object>> callables2 = new
> ArrayList<Callable<Object>>();
> // int count = 0;
> // LinkedList<TCPConnectorHandler> tmpConnectorList = new
> // LinkedList<TCPConnectorHandler>();
> while (itCon.hasNext()) {
> final TCPConnectorHandler con = itCon.next();
> // tmpConnectorList.add(con);
> // count++;
> callables2.add(new Callable<Object>() {
> public Object call() throws Exception {
> // Perform 3 transactions on each connection.
> for (int i = 0; i < 1; i++) {
> executeOnConnection(con);
> }
> return null;
> }
> });
> }
>
> // Operate on each connection.
>
> // Callable<Object>[] callables3 = new
> // Callable[NUMBER_LOAD_ON_THREADPOOL];
>
> // Callable<Object>[] callables = new
> // Callable[NUMBER_LOAD_ON_THREADPOOL];
> // // Issue these connections concurrently.
> // for (int i = 0; i < callables.length; i++) {
> // callables[i] = new Callable<Object>() {
> // public Object call() throws Exception {
> // for (int i = 0; i < CONNECTION_NUMBER
> // / NUMBER_LOAD_ON_THREADPOOL; i++) {
> // // TCPConnectorHandler connectorHandler =
> // // (TCPConnectorHandler) controller
> // // .acquireConnectorHandler(Protocol.TCP);
> // executeOnConnection(connectorHandler);
> // }
> // return null;
> // }
> // };
> // }
> ExecutorService executor = Executors
> .newFixedThreadPool(CONNECTION_THREADPOOL_SIZE);
> // List<Callable<Object>> c = Arrays.asList(callables2);
>
> long start = System.currentTimeMillis();
>
> executor.invokeAll(callables2);
> executor.shutdown();
>
> long interval = System.currentTimeMillis() - start;
> System.out.println("transaction/s: " + transactionCount.get() *
> 1000
> / interval + ", bytes read: " + bytesRead.get()
> + "\n-1 times: " + minusOneCount.get() + ", 0 times: "
> + zeroCount);
>
> Thread.sleep(2000);
> itCon = connectors.iterator();
> while (itCon.hasNext()) {
> TCPConnectorHandler con = itCon.next();
> // con.getSelectorHandler().getPort()
> con.close();
> }
>
> controller.stop();
> }
>
> private void executeOnConnection(TCPConnectorHandler connectorHandler)
> throws IOException {
> try {
> sendRequest(connectorHandler);
> } finally {
> // connectorHandler.close();
> }
> }
>
> private void sendRequest(TCPConnectorHandler connectorHandler)
> throws IOException {
> String str = "GET /"
> + /* icons/apache_pb2.gif */"\r\nHTTP 1.1\r\nHOST:"
> + SERVER_HOST_OR_IP + "\r\nConnection:keep-alive\r\n\r\n";
> connectorHandler.writeToAsyncQueue(ByteBuffer.wrap(str.getBytes()),
> new MyAsyncWriteCallbackHandler(connectorHandler));
> }
>
> private void waitControllerReady() throws InterruptedException {
> controllerReadyLatch.await();
> }
>
> private Controller createController() {
> Controller tmpCtl = new Controller();
> DefaultConnectorHandlerPool connectorPool = new
> DefaultConnectorHandlerPool(
> tmpCtl);
> tmpCtl.setConnectorHandlerPool(connectorPool);
>
> DefaultSelectionKeyHandler keyHandler = new
> DefaultSelectionKeyHandler();
> keyHandler.setTimeout(30 * 1000 * 60);
> tmpCtl.setSelectionKeyHandler(keyHandler);
> tmpCtl.setSelectorHandler(new TCPSelectorHandler(true));
> tmpCtl.addStateListener(new ControllerStateListenerAdapter() {
> @Override
> public void onReady() {
> controllerReadyLatch.countDown();
> }
> });
>
> Pipeline pl = new DefaultPipeline();
> pl.setMaxThreads(50);
> tmpCtl.setPipeline(pl);
>
> // tmpCtl.getConnectorHandlerPool().
>
> return tmpCtl;
> }
>
> }
>

package test.grizzly;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.concurrent.CountDownLatch;

import com.sun.grizzly.Controller;
import com.sun.grizzly.ControllerStateListenerAdapter;
import com.sun.grizzly.DefaultProtocolChain;
import com.sun.grizzly.DefaultProtocolChainInstanceHandler;
import com.sun.grizzly.ProtocolChain;
import com.sun.grizzly.TCPSelectorHandler;
import com.sun.grizzly.filter.EchoFilter;
import com.sun.grizzly.filter.ReadFilter;

public class EchoServer {

    private static final String SERVER_HOST_IP = "190.168.0.113";
    private static final int SERVER_PORT = 11113;

    /**
     * @param args
     * @throws InterruptedException
     * @throws UnknownHostException
     */
    public static void main(String[] args) throws UnknownHostException,
            InterruptedException {
        EchoServer server = new EchoServer();
        server.start();
    }

    private Controller controller;
    protected CountDownLatch controllerReadyLatch = new CountDownLatch(1);

    public void start() throws InterruptedException, UnknownHostException {
        controller = createController();
        new Thread(controller).start();

        controllerReadyLatch.await();

    }

    private Controller createController() throws UnknownHostException {
        Controller tmpCtl = new Controller();
        TCPSelectorHandler tcpSelectorHandler = new TCPSelectorHandler();
        tcpSelectorHandler.setInet(InetAddress.getByName(SERVER_HOST_IP));
        tcpSelectorHandler.setPort(SERVER_PORT);
        tmpCtl.addSelectorHandler(tcpSelectorHandler);
        tmpCtl.addStateListener(new ControllerStateListenerAdapter() {
            @Override
            public void onReady() {
                controllerReadyLatch.countDown();
            }
        });
        tmpCtl
                .setProtocolChainInstanceHandler(new
DefaultProtocolChainInstanceHandler() {
                    private ProtocolChain protocolChain;

                    @Override
                    public ProtocolChain poll() {
                        if (protocolChain == null) {
                            protocolChain = new DefaultProtocolChain();
                        }
                        return protocolChain;
                    }
                });
        tmpCtl.getProtocolChainInstanceHandler().poll().addFilter(
                new ReadFilter());
        tmpCtl.getProtocolChainInstanceHandler().poll().addFilter(
                new EchoFilter());

        return tmpCtl;
    }

}


package test.grizzly;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.Iterator;

public class RawNioClient implements Runnable {
    private InetAddress serverHost;
    private int serverPort;
    private Selector selector;
    private int connectionCount = 0;

    // private SocketChannel socketChannel;

    public RawNioClient(InetAddress serverHost, int serverPort)
            throws IOException {
        this.serverHost = serverHost;
        this.serverPort = serverPort;
        selector = initSelector();
        // socketChannel = initSocketChannel();
    }

    private SocketChannel initSocketChannel() throws IOException {
        SocketChannel sc = SocketChannel.open();
        sc.connect(new InetSocketAddress(serverHost, serverPort));
        sc.configureBlocking(false);
        sc.socket().setReuseAddress(true);
        sc.register(selector, SelectionKey.OP_CONNECT);
        return sc;
    }

    private Selector initSelector() throws IOException {
        return SelectorProvider.provider().openSelector();
    }

    public static void main(String[] args) {
        try {
            new Thread(new RawNioClient(InetAddress.getByName("192.168.0.113
"),
                    11113)).start();
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public void run() {
        while (true) {
            try {
                initSocketChannel();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            if (connectionCount >= 30000) {
                System.out.println("reach 30000 connections");
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            } else {
                try {
                    selector.select();

                    Iterator<SelectionKey> itKey = selector.selectedKeys()
                            .iterator();
                    while (itKey.hasNext()) {
                        SelectionKey key = itKey.next();
                        itKey.remove();
                        if (!key.isValid()) {
                            continue;
                        }
                        if (key.isConnectable()) {
                            doConnect(key);
                        }
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

    private void doConnect(SelectionKey key) {
        SocketChannel sc = (SocketChannel) key.channel();
        try {
            boolean fc = sc.finishConnect();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        connectionCount++;
    }
}


>
>
> 2. i want to iterate over the ConnectorHandlerPool to perform transaction
> on each connection. but it seems that ConnectorHandlerPool does not support
> the iteration explicitly. so as a walk-around, i collect the
> ConnectorHandler after executing ConnectorHandler.finishConnect manually.
>
> May be it's the only way right now. As ConnectorHandlerPool initially
> wasn't introduced to serve existing live connections, but to cache/reuse
> ones, which were released (closed).
>
> thanks.
>
> - Yi Bing
>