Strategy Agent provides an environment for a collection of modules to run and participate in data flows.

Command Line

Syntax:
        strategyagent [commands_file]

The Strategy agent optionally accepts a file containing a limited set of commands that are executed as soon as the agent is started.

Once started, the strategy agent waits until stopped. To shutdown the Strategy Agent, simply kill the process: it has appropriate shutdown hooks registered to stop all its activity before it shuts down.

The commands_file contains one command per line. Commands cannot span multiple lines. Each line has a command name followed by a semicolon ';', followed by command specific syntax to supply parameters to the particular command. Lines beginning with '#' character and empty lines are ignored. The following commands are supported in the commands file:

• createModule
• startModule
• createDataFlow

createModule

Syntax:
        createModule;providerURN;create_parameters

• providerURN is the URN of the module provider whose instance is being created.
• create_parameters is the list of parameters that are being supplied to create the module instance per the syntax specified in {@link org.marketcetera.module.ModuleManagerMXBean} documentation.

For example:

    # Create a module instance of provider metc:surface:color
    # First parameter is a module instance URN value
    #       metc:surface:color:red
    # Second parameter is a URL value
    #       http://red.com
    # Third parameters is a string value
    #       username
    # Fourth parameter is a double value
    #       12.43
    createModule;metc:surface:color;metc:surface:color:red,http://red.com,username,12.43

startModule

Syntax:
        startModule;instanceURN

• instanceURN is the URN of the module instance that is being started.

For example:

    # Starts a module instance with the URN metc:surface:color:red
    startModule;metc:surface:color:red

createDataFlow

Syntax:
        createDataFlow;data_flow_request

• data_flow_request is a string specifying the detail of the data flow that is being setup, per the syntax specified in the {@link org.marketcetera.module.ModuleManagerMXBean} documentation.

Do note that since this command invokes the {@link org.marketcetera.module.ModuleManagerMXBean#createDataFlow(String)} API to create the data flow, the sink module is always automatically appended to every data flow being created.

For example:

    # Sets up a data flow with the module instance matching the URN
    # 'metc:mdata' emitting data based on the request parameter 'symbol=ibm',
    # the strategy module instance matching the URN 'metc:strategy::vegas'
    # processing the data and the sink module receiving all the data.
    createDataFlow;metc:mdata;symbol=ibm^metc:strategy::vegas

Module Providers

The module jars can be added to the agent by copying them into the modules/jars sub-directory. The Strategy Agent discovers all the jars when it's initialized. If new jars are added after the agent has been started, the strategy agent can be asked to discover them by invoking the {@link org.marketcetera.module.ModuleManagerMXBean#refresh()} API via JMX.

Classloading

The strategy agent uses a {@link java.net.URLClassLoader} instance to load provider classes from the modules/jars sub-directory. Since a custom classloader is used, the system classloader cannot find any of the provider classes.

This is usually not a problem unless the provider code depends on the thread's context classloader to be set to a classloader that is able to load all the provider classes. Many third party libraries do depend on the thread context classloader value to be able to correctly load classes.

The strategy agent sets the thread context classloader to the custom classloader that is used to load the providers before loading any of the provider classes. This ensures that the provider code is invoked with the thread context classloader set to the same classloader that loaded it. Moreover, the module manager ensures that the thread context classloader is set to the custom classloader when any module manager MXBean operations or factory / instance MXBean operations are invoked.

Module Configuration

The Strategy Agent uses the {@link org.marketcetera.module.PropertiesConfigurationProvider} to provide default property values to the module factories and instances. The properties files, having appropriate names and key-value pairs as described in the property configuration provider documentation, can be copied into the modules/conf sub-directory.

Management and Monitoring

The primary means of controlling the Strategy Agent is via JMX. Once the strategy agent is up and running, clients can connect to its platform MBean server and control its operation via the {@link org.marketcetera.module.ModuleManagerMXBean} interface.

Logging

The Strategy Agent is configured to print informational messages from the agent and all the data received by the sink module to its console. The rest of the messages are copied to its log file in the log sub-directory. The logging configuration is done via the log4j.properties file in the conf sub-directory. The category names for Strategy Agent and sink messages are org.marketcetera.strategyagent.StrategyAgent and SINK, the logging configuration for these two categories can be altered to change what messages are printed on the strategyagent console.