org.gridgain.grid.spi.deployment
Interface GridDeploymentSpi

All Superinterfaces:

GridSpi

All Known Implementing Classes:

GridLocalDeploymentSpi, GridUriDeploymentSpi

@Apache20LicenseCompatible
public interface GridDeploymentSpi
extends GridSpi

Grid deployment SPI is in charge of deploying tasks and classes from different sources.

Class loaders that are in charge of loading task classes (and other classes) can be deployed directly by calling GridDeploymentSpi.register(ClassLoader, Class)} method or by SPI itself, for example by asynchronously scanning some folder for new tasks. When method GridDeploymentSpi.findResource(String) is called by the system, SPI must return a class loader associated with given class. Every time a class loader gets (re)deployed or released, callbacks GridDeploymentListener.onUnregistered(ClassLoader)} must be called by SPI.

If peer class loading is enabled (which is default behavior, see GridConfiguration.isPeerClassLoadingEnabled()), then it is usually enough to deploy class loader only on one grid node. Once a task starts executing on the grid, all other nodes will automatically load all task classes from the node that initiated the execution. Hot redeployment is also supported with peer class loading. Every time a task changes and gets redeployed on a node, all other nodes will detect it and will redeploy this task as well. Note that peer class loading comes into effect only if a task was not locally deployed, otherwise, preference will always be given to local deployment.

Gridgain provides the following GridDeploymentSpi implementations:

• GridLocalDeploymentSpi
• GridUriDeploymentSpi

See Also:

Documentation
Email Support
Online Forums
Issue Tracking

Author: 2005-2008 Copyright © GridGain Systems. All Rights Reserved. ver. 2.1.0

	Nikita Ivanov, GridGain Systems nivanov@gridgain.com
	Dmitriy Setrakyan, GridGain Systems dsetrakyan@gridgain.com
	Alexander Magdenko, GridGain Systems amagdenko@gridgain.com
	Boris Suchodoev, GridGain Systems bsuchodoev@gridgain.com
	Denis Kharlamov, GridGain Systems dkharlamov@gridgain.com
	close

Method Summary

GridDeploymentResource	findResource(String rsrcName) Finds class loader for the given class.
boolean	register(ClassLoader ldr, Class<?> rsrc) Registers a class loader with this SPI.
void	setListener(GridDeploymentListener lsnr) Sets deployment event listener.
boolean	unregister(String rsrcName) Unregisters all class loaders that have a class with given name or have a class with give GridTaskName value.

Methods inherited from interface org.gridgain.grid.spi.GridSpi

getName, getNodeAttributes, onContextDestroyed, onContextInitialized, spiStart, spiStop

Method Detail

findResource

GridDeploymentResource findResource(String rsrcName)

Finds class loader for the given class.

Parameters:

rsrcName - Class name or class alias to find class loader for.

Returns:

Deployed class loader, or null if not deployed.

register

boolean register(ClassLoader ldr,
                 Class<?> rsrc)
                 throws GridSpiException

Registers a class loader with this SPI. This method exists to be able to add external class loaders to deployment SPI. Deployment SPI may also have its own class loaders. For example, in case of GAR deployment, every GAR file is loaded and deployed with a separate class loader maintained internally by the SPI.

The array of classes passed in should be checked for presence of GridTaskName annotations. The classes that have this annotation should be accessible by this name from GridDeploymentSpi.findResource(String) method.

Throws:

GridSpiException - If registration failed.

Parameters:

ldr - Class loader to register.

rsrc - Class that should be checked for aliases. Currently the only alias in the system is GridTaskName for task classes; in future, there may be others.

Returns:

True if resource was registered.

unregister

boolean unregister(String rsrcName)

Unregisters all class loaders that have a class with given name or have a class with give GridTaskName value.

Parameters:

rsrcName - Either class name or GridTaskName value for a class whose class loader needs to be unregistered.

Returns:

True if resource was unregistered.

setListener

void setListener(GridDeploymentListener lsnr)

Sets deployment event listener. Grid implementation will use this listener to properly add and remove various deployments.

Parameters:

lsnr - Listener for deployment events.