org.cougaar.tools.server

Notes on the app-server

The "App-Server" is an application server (daemon) that allows remote clients to:

1. launch and kill processes, plus listen for the output of those processes
2. access the file system to read and write files
3. list running processes on the system ("ps")

As of Cougaar 9.0 there is little security built into the server, so use at your own risk. If the machines are behind a firewall then you're probably okay...

The AppServer is the "main" program to launch the server. The default port address is 8484. ".props" filenames that are specified as arguments are loaded by the server and used to set default process properties.

The RemoteHostRegistry allows a remote client to lookup an app-server on a specified (host:port) address.

There are several example app-server clients:

• The "org.cougaar.tools.server.examples" package, with source under "server/examples/*", contains two example consoles:
  • "MinConsole", which is a command-line test rig
  • "GuiConsole", which is simple Swing-based UI
  • The "CSMARTConsole", which is integrated into CSMART.
  • The "Manager", which is in the "manager" module.

  FIXME:
  The interfaces have a lot of "throws Exception" in them, which is messy. With a little work most of these methods could probably become something more specific, such as "throws IOException".

Example usage:

 // create streams
 DualStreamBuffer dsb = new DualStreamBuffer();
 PrintStream pout = new PrintStream(dsb.getOutputStream(true));
 PrintStream perr = new PrintStream(dsb.getOutputStream(false));
 // use streams as usual
 pout.print("example std-out");
 perr.print("some error");
 pout.print("more std-out");
 // replay to standard-out and standard-err
 dsb.writeTo(System.out, System.err);
 

The internal representation has been optimized to make both appending and the writeTo(*) methods efficient (memory + time).

NOTE: this class is not internally thread-safe! If multiple threads need access to the same DualStreamBuffer instance then they must externally synchronized their actions.

Soon to be deprecated -- see NodeEventTranslator.