If this is done in Java code, you could use byteman to change the behavior. Intercepting and changing the data flow in the TCP/IP stack itself gets more tricky; you have to insert a packet filter and then drop/reorder packets. In Java, you might be able to use jnetpcap, which allows you to get access to the individual packets. Maybe iptables will also allow you to do this, but it's rather static. On 1/18/12 10:05 PM, Michal Linhard wrote: > Hi all, > > probably stupid question from the area of java server programming and > networking if anyone's interrested: > (otherwise sorry for spam) > > is there a simple way of creating a server in java that would always > give me connection timeout ? (not connection refused, nor socket timeout > during read) > is it even possible to control establishing tcp connection from java ? > > what layer does control this ? > it seems that once you bind a socket the connections are automatically > established. > probably on some JVM level ? > so when I get > > java.net.ConnectException: Connection timed out > at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) > at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) > at org.infinispan.client.hotrod.impl.transport.tcp.TcpTransport.<init>(TcpTransport.java:80) > > > this means that server JVM or OS networking layer or whatever was so > stressed that it didn't have time to respond with SYN,ACK flagged packet > to establish the connection ? > > m. > > > ----------- my test code: > public class EchoServer { > public static void main(String[] args) { > try { > ServerSocketChannel serverChannel = ServerSocketChannel.open(); > InetSocketAddress isa = new InetSocketAddress("localhost", 9090); > serverChannel.socket().bind(isa); > Thread.sleep(20000); > } catch (Exception e) { > e.printStackTrace(); > } > > } > } > > public class EchoClient { > public static void main(String[] args) { > long startTime = System.currentTimeMillis(); > try { > SocketAddress serverAddress = new > InetSocketAddress("localhost", 9090); > SocketChannel socketChannel = SocketChannel.open(); > Socket socket = socketChannel.socket(); > socket.connect(serverAddress, 5000); > socket.setSoTimeout(5000); > BufferedInputStream socketInputStream = new > BufferedInputStream(socket.getInputStream(), socket.getReceiveBufferSize()); > BufferedOutputStream socketOutputStream = new > BufferedOutputStream(socket.getOutputStream(), socket.getSendBufferSize()); > PrintWriter out = new PrintWriter(socketOutputStream); > out.println("Hello"); > out.flush(); > BufferedReader in = new BufferedReader(new > InputStreamReader(socketInputStream)); > System.out.println(in.readLine()); > } catch (Exception e) { > System.out.println("Exception occured after " + > (System.currentTimeMillis() - startTime) + " ms"); > e.printStackTrace(); > } > } > } > -- Bela Ban Lead JGroups (http://www.jgroups.org) JBoss / Red Hat _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev

I wanted to test my theory that the hot rod client connection timeout we added as part of https://issues.jboss.org/browse/ISPN-1565 is being ignored (taking into account https://issues.jboss.org/browse/ISPN-1755) I configured both socket timeout and connect timeout for 2 min but in certain tests I'm getting connection timeuot after cca 20secs. m.

On 01/19/2012 12:01 PM, Manik Surtani wrote: > What is this for? Perhaps just mock up the client to use a mock socket? > > On 19 Jan 2012, at 12:57, Bela Ban wrote: > >> If this is done in Java code, you could use byteman to change the behavior. >> >> Intercepting and changing the data flow in the TCP/IP stack itself gets >> more tricky; you have to insert a packet filter and then drop/reorder >> packets. In Java, you might be able to use jnetpcap, which allows you to >> get access to the individual packets. >> >> Maybe iptables will also allow you to do this, but it's rather static. >> >> On 1/18/12 10:05 PM, Michal Linhard wrote: >>> Hi all, >>> >>> probably stupid question from the area of java server programming and >>> networking if anyone's interrested: >>> (otherwise sorry for spam) >>> >>> is there a simple way of creating a server in java that would always >>> give me connection timeout ? (not connection refused, nor socket timeout >>> during read) >>> is it even possible to control establishing tcp connection from java ? >>> >>> what layer does control this ? >>> it seems that once you bind a socket the connections are automatically >>> established. >>> probably on some JVM level ? >>> so when I get >>> >>> java.net.ConnectException: Connection timed out >>> at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) >>> at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) >>> at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) >>> at org.infinispan.client.hotrod.impl.transport.tcp.TcpTransport.<init>(TcpTransport.java:80) >>> >>> >>> this means that server JVM or OS networking layer or whatever was so >>> stressed that it didn't have time to respond with SYN,ACK flagged packet >>> to establish the connection ? >>> >>> m. >>> >>> >>> ----------- my test code: >>> public class EchoServer { >>> public static void main(String[] args) { >>> try { >>> ServerSocketChannel serverChannel = ServerSocketChannel.open(); >>> InetSocketAddress isa = new InetSocketAddress("localhost", 9090); >>> serverChannel.socket().bind(isa); >>> Thread.sleep(20000); >>> } catch (Exception e) { >>> e.printStackTrace(); >>> } >>> >>> } >>> } >>> >>> public class EchoClient { >>> public static void main(String[] args) { >>> long startTime = System.currentTimeMillis(); >>> try { >>> SocketAddress serverAddress = new >>> InetSocketAddress("localhost", 9090); >>> SocketChannel socketChannel = SocketChannel.open(); >>> Socket socket = socketChannel.socket(); >>> socket.connect(serverAddress, 5000); >>> socket.setSoTimeout(5000); >>> BufferedInputStream socketInputStream = new >>> BufferedInputStream(socket.getInputStream(), socket.getReceiveBufferSize()); >>> BufferedOutputStream socketOutputStream = new >>> BufferedOutputStream(socket.getOutputStream(), socket.getSendBufferSize()); >>> PrintWriter out = new PrintWriter(socketOutputStream); >>> out.println("Hello"); >>> out.flush(); >>> BufferedReader in = new BufferedReader(new >>> InputStreamReader(socketInputStream)); >>> System.out.println(in.readLine()); >>> } catch (Exception e) { >>> System.out.println("Exception occured after " + >>> (System.currentTimeMillis() - startTime) + " ms"); >>> e.printStackTrace(); >>> } >>> } >>> } >>> >> -- >> Bela Ban >> Lead JGroups (http://www.jgroups.org) >> JBoss / Red Hat >> _______________________________________________ >> infinispan-dev mailing list >> infinispan-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/infinispan-dev > -- > Manik Surtani > manik(a)jboss.org > twitter.com/maniksurtani > > Lead, Infinispan > http://www.infinispan.org > > > > > _______________________________________________ > infinispan-dev mailing list > infinispan-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/infinispan-dev