/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.zookeeper.test;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import org.apache.jute.BinaryOutputArchive;
import org.apache.zookeeper.proto.ConnectRequest;
public class MaxCnxnsTest extends ClientBase {
final private int numCnxns = 5;
protected void setUp() throws Exception {
maxCnxns = numCnxns;
super.setUp();
}
/**
* Verify the ability to limit the number of concurrent connections.
* @throws IOException
* @throws InterruptedException
*/
public void testMaxCnxns() throws IOException, InterruptedException{
SocketChannel[] sockets = new SocketChannel[numCnxns+5];
String split[] = hostPort.split(":");
String host = split[0];
int port = Integer.parseInt(split[1]);
int numConnected = 0;
/*
* For future unwary socket programmers: although connect 'blocks' it
* does not require an accept on the server side to return. Therefore
* you can not assume that all the sockets are connected at the end of
* this for loop.
*/
for (int i=0;i<sockets.length;++i) {
SocketChannel sChannel = SocketChannel.open();
sChannel.connect(new InetSocketAddress(host,port));
sockets[i] = sChannel;
}
// Construct a connection request
ConnectRequest conReq = new ConnectRequest(0, 0,
10000, 0, "password".getBytes());
ByteArrayOutputStream baos = new ByteArrayOutputStream();
BinaryOutputArchive boa = BinaryOutputArchive.getArchive(baos);
boa.writeInt(-1, "len");
conReq.serialize(boa, "connect");
baos.close();
ByteBuffer bb = ByteBuffer.wrap(baos.toByteArray());
bb.putInt(bb.capacity() - 4);
/* Send a connect request. Any socket that has been closed (or at least
* not added to the cnxn list on the server) will not have any bytes to
* read and get an eof.
*
* The trick here was finding a call that caused the server to put
* bytes in the input stream without closing the cnxn. None of
* the four letter commands do that, so we actually try to create
* a session which should send us something back, while maintaining
* the connection.
*/
for (int i=0;i<sockets.length;++i) {
try {
bb.rewind();
int eof = sockets[i].write(bb);
// If the socket times out, we count that as failed -
// the server should respond within 10s
sockets[i].socket().setSoTimeout(10000);
if (!sockets[i].socket().isClosed()){
eof = sockets[i].socket().getInputStream().read();
if (eof != -1) {
numConnected++;
}
}
}
catch (IOException io) {
// "Connection reset by peer"
}
}
assertSame(numCnxns,numConnected);
}
}