com.zfabrik.workers.home
Interface IWorkerProcess

public interface IWorkerProcess

A worker process is managed by the home process as explained in IHomeLayout.

Worker process component definitions have no resources beyond a property sheet. A worker process definition typically looks like this:

 com.zfabrik.component.type=com.zfabrik.worker
 # worker configuration
 #
 # target states
 #
 worker.states=environment/webWorkerUp
 
 #
 # max worker thread pool concurrency
 #
 worker.concurrency=15


 #
 # debug port
 #
 worker.debug.port=5001
 #
 # timeout (in ms) before the worker will be forcefully killed at worker stop
 #
 worker.process.timeouts.termination=20000
 #
 # vm options
 #
 worker.process.vmOptions=\
  -Xmx128m -Xms128m -XX:+HeapDumpOnOutOfMemoryError \
  -Duser.language=en \
  -Dcom.sun.management.jmxremote.port=7778
 

Properties in detail:

worker.process.vmOptions

General virtual machine parameters for the worker process. See for example http://blogs.sun.com/watt/resource/jvm-options-list.html for a general overview.

worker.states

Comma-separated list of target state (components) of the worker process (see also ISystemState. The worker process, when starting, will try to attain these target states and will try so again during each verification and synchronization.

worker.concurrency

Size of application thread pool (see ApplicationThreadPool). In general this thread pool is used for application type work (e.g. for web requests or parallel execution within the application). This property helps achieving a simple but effective concurrent load control

worker.process.timeouts.start

Timeout in milliseconds. This time out determines when the worker process implementation will forcibly kill the worker process if it has not reported startup completion until then.

worker.process.timeouts.termination

Timeout in milliseconds. This time out determines when the worker process implementation will forcibly kill the worker process if it has not terminated after this timeout has passed since it was asked to terminate.

worker.process.timeouts.communication

Timeout in milliseconds. This time out is the default timeout that determines the time passed after which the worker process implementation will forcibly kill a worker process if a message request has not returned.

worker.debug

Debugging for the worker process will be configured if this property is set to true and the home process has debugging enabled. Otherwise the worker process will not be configured for debugging.

worker.debug.port

The debug port to use for this worker process, if it is configured for debugging (see WORKER_DEBUG)

Field Summary

static String	DEBUG_PORT The debug port to use for this worker process, if it is configured for debugging (see WORKER_DEBUG)
static String	MSG_NODE msg header providing id of target node if one specific
static String	MSG_TARGET msg header describing the target of a message
static String	MSG_TARGET_ALL
static String	MSG_TARGET_HOME
static String	MSG_TARGET_NODE
static String	MSG_TIMEOUT msg header providing the time out of the message operation (per node).
static short	NOT_STARTED
static short	STARTED
static short	STARTING
static String	STATES Target states of the worker process (see also ISystemState.
static short	STOPPING
static String	TO_MSG Timeout in milliseconds.
static String	TO_MSG_DEF
static String	TO_START Timeout in milliseconds.
static String	TO_START_DEF
static String	TO_TERM Timeout in milliseconds.
static String	TO_TERM_DEF
static String	VMOPTS General virtual machine parameters for the worker process.
static String	WORKER_CONCURRENCY Size of application thread pool (see ApplicationThreadPool).
static String	WORKER_DEBUG Debugging for the worker process will be configured if this property is set to true and the home process has debugging enabled.

Method Summary

short	getState() get the state of this worker
Map<String,Serializable>	sendMessage(Map<String,Serializable> args, long timeout) send a message to the process.
Map<String,Serializable>	sendMessage(Map<String,Serializable> args, long timeout, boolean killOnTimeOut) send a message to the process.
void	start() start this worker
void	stop() Stop this worker

Field Detail

VMOPTS

static final String VMOPTS

General virtual machine parameters for the worker process. See for example http://blogs.sun.com/watt/resource/jvm-options-list.html for a general overview.

See Also:

Constant Field Values

STATES

static final String STATES

Target states of the worker process (see also ISystemState. The worker process, when starting, will try to attain these target states and will try so again during each verification and synchronization.

See Also:

Constant Field Values

TO_START

static final String TO_START

Timeout in milliseconds. This time out determines when the worker process implementation will forcibly kill the worker process if it has not reported startup completion until then.

See Also:

Constant Field Values

TO_TERM

static final String TO_TERM

Timeout in milliseconds. This time out determines when the worker process implementation will forcibly kill the worker process if it has not terminated after this timeout has passed since it was asked to terminate.

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Constant Field Values

TO_MSG

static final String TO_MSG

Timeout in milliseconds. This time out is the default timeout that determines the time passed after which the worker process implementation will forcibly kill a worker process if a message request has not returned.

See Also:

Constant Field Values

WORKER_CONCURRENCY

static final String WORKER_CONCURRENCY

Size of application thread pool (see ApplicationThreadPool). In general this thread pool is used for application type work (e.g. for web requests or parallel execution within the application). This property helps achieving a simple but effective concurrent load control

See Also:

Constant Field Values

WORKER_DEBUG

static final String WORKER_DEBUG

Debugging for the worker process will be configured if this property is set to true and the home process has debugging enabled.

Otherwise the worker process will not be configured for debugging.

See Also:

Constant Field Values

DEBUG_PORT

static final String DEBUG_PORT

The debug port to use for this worker process, if it is configured for debugging (see WORKER_DEBUG)

See Also:

Constant Field Values

TO_START_DEF

static final String TO_START_DEF

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Constant Field Values

TO_TERM_DEF

static final String TO_TERM_DEF

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Constant Field Values

TO_MSG_DEF

static final String TO_MSG_DEF

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Constant Field Values

MSG_TARGET

static final String MSG_TARGET

msg header describing the target of a message

See Also:

Constant Field Values

MSG_TARGET_NODE

static final String MSG_TARGET_NODE

See Also:

Constant Field Values

MSG_TARGET_ALL

static final String MSG_TARGET_ALL

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Constant Field Values

MSG_TARGET_HOME

static final String MSG_TARGET_HOME

See Also:

Constant Field Values

MSG_NODE

static final String MSG_NODE

msg header providing id of target node if one specific

See Also:

Constant Field Values

MSG_TIMEOUT

static final String MSG_TIMEOUT

msg header providing the time out of the message operation (per node). Can be provided as long or as string

See Also:

Constant Field Values

NOT_STARTED

static final short NOT_STARTED

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Constant Field Values

STARTING

static final short STARTING

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Constant Field Values

STARTED

static final short STARTED

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STOPPING

static final short STOPPING

See Also:

Constant Field Values

Method Detail

sendMessage

Map<String,Serializable> sendMessage(Map<String,Serializable> args,
                                     long timeout)
                                     throws IOException

send a message to the process. Note: message sending happens completely synchronously. A message is just a name value map. All content must be serializable (preferrably string). Its return value is also just a map.

Parameters:

args - a map of name value pairs that will be serialized as strings to the slave

timeout - timeout for message answering in ms.

Returns:

a result map

Throws:

IOException

sendMessage

Map<String,Serializable> sendMessage(Map<String,Serializable> args,
                                     long timeout,
                                     boolean killOnTimeOut)
                                     throws IOException

send a message to the process. Note: message sending happens completely synchronously. A message is just a name value map. All content must be serializable (preferrably string). Its return value is also just a map.

Parameters:

args - a map of name value pairs that will be serialized as strings to the slave

timeout - timeout for message answering in ms.

killOnTimeOut - if true a timeout will lead to a process termination.

Returns:

a result map

Throws:

IOException

stop

void stop()

Stop this worker

start

void start()

start this worker

getState

short getState()

get the state of this worker