edu.sdsc.inca
Class Server

java.lang.Object
  edu.sdsc.inca.Component
      edu.sdsc.inca.Server

public class Server

extends Component

Author:

Cathie Olschanowsky, Jim Hayes, Shava Smallen

A multithreaded server that speaks the Inca protocol. Provides the basic implementation for all Java servers within the Inca Framework.
NOTE: All of the set* methods that manipulate Server configuration have no effect if called while the Server is running.

If the server is shut down using SIGINT there is a hook that will shut it down properly. This takes a few seconds, but makes sure that all currently active work is finished before shutdown is completed. On a SIGKILL work may be lost and the state may be unstable.

Nested Class Summary

protected class	Server.ClientDispatcher A class that listens on a server socket and adds new client connections to a work queue.
protected class	Server.ServerShutdownHook This Class is run in a seperate thread when the server is shut down using ^C or SIGINT.

Field Summary

static int	ACCEPT_TIMEOUT
protected Server.ClientDispatcher	cd
static int	CLIENT_TIMEOUT
protected static org.apache.log4j.Logger	logger
static java.lang.String	SERVER_OPTS
protected java.net.ServerSocket	ssocket
protected java.lang.String	tempPath
protected int	workerCount
protected Worker[]	workers
protected WorkQueue	workQueue

Fields inherited from class edu.sdsc.inca.Component

authenticate, cert, certPath, COMPONENT_OPTS, hostname, key, keyPath, logFile, password, port, trusted, trustedPath

Constructor Summary

Server()

Method Summary

java.lang.String	getTempPath() Returns the path where the server stores temporary files.
int	getWorkerCount() Returns the number of worker threads this server uses.
boolean	isRunning() Returns true iff the Server is accepting connections.
static void	main(java.lang.String[] args) A main function to start a generic server.
void	runServer() Start a thread that accepts and dispatches client connections.
void	setConfiguration(java.util.Properties config) A convenience function for setting multiple configuration properties at once.
void	setTempPath(java.lang.String path) Sets the directory path where the Server stores temporary files.
void	setWorkerCount(int count) Sets the number of workers the Server uses to handle incoming messages.
void	shutdown() Asks the Server to shutdown.

Methods inherited from class edu.sdsc.inca.Component

addTrustedCert, configComponent, createSocket, getAuthenticate, getCertificate, getCertificatePath, getHostname, getKey, getKeyPath, getLogFile, getPassword, getPort, getTrustedCertificates, getTrustedPath, getUri, openResourceStream, readCredentials, readVersion, setAuthenticate, setCertificatePath, setHostname, setKeyPath, setLogFile, setPassword, setPort, setTrustedPath

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ACCEPT_TIMEOUT

public static final int ACCEPT_TIMEOUT

See Also:

Constant Field Values

CLIENT_TIMEOUT

public static final int CLIENT_TIMEOUT

See Also:

Constant Field Values

SERVER_OPTS

public static final java.lang.String SERVER_OPTS

logger

protected static org.apache.log4j.Logger logger

tempPath

protected java.lang.String tempPath

workerCount

protected int workerCount

cd

protected Server.ClientDispatcher cd

ssocket

protected java.net.ServerSocket ssocket

workQueue

protected WorkQueue workQueue

workers

protected Worker[] workers

Constructor Detail

Server

public Server()

Method Detail

getTempPath

public java.lang.String getTempPath()

Returns the path where the server stores temporary files.

Returns:

the temp directory path

getWorkerCount

public int getWorkerCount()

Returns the number of worker threads this server uses.

Returns:

the number of worker threads

isRunning

public boolean isRunning()

Returns true iff the Server is accepting connections.

Returns:

true if the server is accepting connections

runServer

public void runServer()
               throws java.lang.Exception

Start a thread that accepts and dispatches client connections.

Throws:

java.lang.Exception - if the server fails to start

setConfiguration

public void setConfiguration(java.util.Properties config)
                      throws ConfigurationException

A convenience function for setting multiple configuration properties at once. In addition to the keys recognized by the superclass, recognizes: "numthreads", * the number of threads in the worker pool; "var", the path to the temporary file dir.

Overrides:

setConfiguration in class Component

Parameters:

config - contains server configuration values

Throws:

ConfigurationException - on a faulty configuration property value

setTempPath

public void setTempPath(java.lang.String path)
                 throws ConfigurationException

Sets the directory path where the Server stores temporary files.

Parameters:

path - the temporary directory path

Throws:

ConfigurationException - if the path can't be read from the classpath

setWorkerCount

public void setWorkerCount(int count)

Sets the number of workers the Server uses to handle incoming messages.

Parameters:

count - The (positive) worker count

shutdown

public void shutdown()
              throws java.lang.InterruptedException

Asks the Server to shutdown. Interrupts the server and each of its workers. The workers will finish their current task; the server shuts down once all workers have finished. This could take a while.

Throws:

java.lang.InterruptedException - if the shutdown is interrupted

main

public static void main(java.lang.String[] args)

A main function to start a generic server. It takes command-line arguments for each Server configuration value:

 usage: java edu.sdsc.inca.Server

  -a,--auth yes|no       Authenticate the connection?
  -c,--cert        Path to the server certificate
  -h,--help              Prints a short help and usage statement
  -h,--hostname  Hostname of server if different than what Java
                         discovers
  -i,--init        Path to server configuration properties file.
  -k,--key         Path to the server key
  -n,--numthreads   # of worker threads that the server runs
  -P,--password yes|no   Read encryption password from stdin
  -p,--port         The port for the server to listen on
  -t,--trusted     Path to a directory containing all of the
                         trusted certificates.
  -T,--taskwait     # milliseconds for timing out task I/O
  -v,--var         The directory the server should use to save
                         temp files.  Must be an absolute path.
  -V,--version           Print program version and exit.
  -w,--wait         # millisecs between shutdown checks
 

Each of these values may also be specified in the initialization file or in system properties defined via the -D switch. In both of these cases, the configuration name must be prefixed with "inca.server.", e.g., use "inca.server.numthreads" to specify the numthreads value. Command line arguments override any properties specified in this fashion.

Parameters:

args - command line arguments, as above.