Documentation

• About
• Overview
• Reactor
• Tcp Crusher
• Datagram Crusher
• Throttling
• Performance
• Filters
• Dumping
• Samples
• Command Line

Project Documentation

• Project Information

NetCrusher TCP and UDP proxy for Java

NetCrusher is a java TCP/UDP proxy framework and command line tool that allows to test software service for network failover.

NetCrusher proxy framework:

• emulates network failures
• emulates frozen connection
• supports both TCP and UDP
• supports multiple dynamic connections through the same proxy tunnel
• allows to check the state of connections
• allows to filter/dump data
• supports throttling (delay and/or throughput control)
• high perfomance (no excessive copying for TCP)
• garbage-less buffering
• supports IP4/IP6

NetCrusher is build on top of Java 8 NIO and has no external dependencies except SLF4J.

Project is hosted on GitHub

Download the latest dist.tar.gz to get the command line tool.

NioReactor reactor = new NioReactor();

TcpCrusher crusher = TcpCrusherBuilder.builder()
    .withReactor(reactor)
    .withBindAddress("localhost", 10080)
    .withConnectAddress("google.com", 80)
    .buildAndOpen();

// ... some actions

// emulate reconnect
crusher.reopen();

// ... check the client connection is reestablished successfully

// closing
crusher.close();
reactor.close();

NioReactor reactor = new NioReactor();

DatagramCrusher crusher = DatagramCrusherBuilder.builder()
    .withReactor(reactor)
    .withBindAddress("localhost", 10188)
    .withConnectAddress("time-nw.nist.gov", 37)
    .buildAndOpen();

// ... some actions

// check data is sent
Assert.assertTrue(crusher.getInner().getReadDatagramMeter().getTotal() > 0);

// closing
crusher.close();
reactor.close();

$ ./run-tcp-crusher.sh 127.0.0.1:12345 google.com:80
# Version: 0.10
# Print `HELP` for the list of the commands
# enter the command in the next line
CLOSE
[20:19:20.586] INFO  TcpCrusher </127.0.0.1:12345>-<google.com/64.233.161.101:80> is closed
[20:19:20.586] INFO  Crusher is closed
# enter the command in the next line
OPEN
[20:19:21.655] INFO  TcpCrusher </127.0.0.1:12345>-<google.com/64.233.161.101:80> is open
[20:19:21.655] INFO  Crusher is open

<dependency>
    <groupId>com.github.netcrusherorg</groupId>
    <artifactId>netcrusher-core</artifactId>
    <version>0.10</version>
</dependency>