org.gridgain.grid
Interface GridNode

All Superinterfaces:

Serializable

@Apache20LicenseCompatible
public interface GridNode
extends Serializable

Interface representing a single grid node. Use GridNode.getAttribute(String) or GridNode.getMetrics() to get static and dynamic information about remote nodes. GridNode list, which includes all nodes within task topology, is provided to GridTask.map(List, Object) method. You can also get a handle on discovered nodes by calling any of the following methods:

• Grid.getLocalNode()
• Grid.getRemoteNodes()
• Grid.getAllNodes()

Grid Node Attributes

You can use grid node attributes to provide static information about a node. This information is initialized once within grid, during node startup, and remains the same throughout the lifetime of a node. Use GridConfiguration.getUserAttributes() method to initialize your custom node attributes at startup. For example, to provide benchmark data about every node from Spring XML configuration file, you would do the following:

 <bean id="grid.cfg" class="org.gridgain.grid.GridConfigurationAdapter" scope="singleton">
     ...
     <property name="userAttributes">
         <map>
             <entry key="grid.node.benchmark">
                 <bean class="org.gridgain.grid.benchmarks.GridLocalNodeBenchmark" init-method="start"/>
             </entry>
         </map>
     </property>
     ...
 </bean>
 

The system adds the following attributes automatically:

• System.getProperties() - All system properties.
• System.getenv(String) - All environment properties.
• org.gridgain.build.ver - GridGain build version.
• org.gridgain.jit.name - Name of JIT compiler used.
• org.gridgain.net.itf.name - Name of network interface.
• org.gridgain.user.name - Operating system user name.
• org.gridgain.grid.name - Grid name (see Grid.getName()).
• spiName.org.gridgain.spi.class - SPI implementation class for every SPI, where spiName is the name of the SPI (see GridSpi.getName().
• spiName.org.gridgain.spi.ver - SPI version for every SPI, where spiName is the name of the SPI (see GridSpi.getName().

Note that all System and Environment properties for all nodes are automatically included into node attributes. This gives you an ability to get any information specified in System.getProperties() about any node. So for example, in order to print out information about Operating System for all nodes you would do the following:

 for (GridNode node : GridFactory.getGrid().getAllNodes()) {
     System.out.println("Operating system name: " + node.getAttribute("os.name"));
     System.out.println("Operating system architecture: " + node.getAttribute("os.arch"));
     System.out.println("Operating system version: " + node.getAttribute("os.version"));
 }
 

Grid Node Metrics

Grid node metrics (see GridNode.getMetrics()) are updated frequently for all nodes and can be used to get dynamic information about a node. The frequency of update is often directly related to the heartbeat exchange between nodes. So if, for example, default GridMulticastDiscoverySpi is used, the metrics data will be updated every 3 seconds by default.

Grid node metrics provide information about other nodes that can frequently change, such as Heap and Non-Heap memory utilization, CPU load, number of active and waiting grid jobs, etc... This information can become useful during job collision resolution or GridTask.map(List, Object) operation when jobs are assigned to remote nodes for execution. For example, you can only pick nodes that don't have any jobs waiting to be executed.

Local node metrics are registered as MBean and can be accessed from any JMX management console. The simplest way is to use standard jconsole that comes with JDK as it also provides ability to view any node parameter as a graph.



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

<T extends Serializable> T	getAttribute(String name) Gets a node attribute.
<T extends Serializable> Map<String,T>	getAttributes() Gets all node attributes.
UUID	getId() Gets globally unique node ID.
GridNodeMetrics	getMetrics() Gets metrics for this node.
String	getPhysicalAddress() Gets physical address of the node.

Method Detail

getId

UUID getId()

Gets globally unique node ID.

Returns:

Globally unique node ID.

getPhysicalAddress

String getPhysicalAddress()

Gets physical address of the node. In most cases, although it is not strictly guaranteed, it is an IP address of a node.

Returns:

Physical address of the node.

getAttribute

<T extends Serializable> T getAttribute(String name)

Gets a node attribute. Attributes are assigned to nodes at startup via GridConfiguration.getUserAttributes() method.

The system adds the following attributes automatically:

• System.getProperties() - All system properties.
• System.getenv(String) - All environment properties.
• org.gridgain.build.ver - GridGain build version.
• org.gridgain.jit.name - Name of JIT compiler used.
• org.gridgain.net.itf.name - Name of network interface.
• org.gridgain.user.name - Operating system user name.
• org.gridgain.grid.name - Grid name (see Grid.getName()).
• spiName.org.gridgain.spi.class - SPI implementation class for every SPI, where spiName is the name of the SPI (see GridSpi.getName().
• spiName.org.gridgain.spi.ver - SPI version for every SPI, where spiName is the name of the SPI (see GridSpi.getName().

Note that attributes cannot be changed at runtime.

Type Parameters:

T - Attribute Type.

Parameters:

name - Attribute name. Note that attribute names starting with org.gridgain are reserved for internal use.

Returns:

Attribute value.

getMetrics

GridNodeMetrics getMetrics()

Gets metrics for this node. Note that node metrics are constantly updated and provide up to date information about nodes. For example, you can get an idea about CPU load on remote node via GridNodeMetrics.getCurrentCpuLoad() method and use it during GridTask.map(List, Object) or during collision resolution.

Node metrics are updated with some delay which is directly related to heartbeat frequency. For example, when used with default GridMulticastDiscoverySpi the update will happen every 2 seconds.

Returns:

Runtime metrics for this node.

getAttributes

<T extends Serializable> Map<String,T> getAttributes()

Gets all node attributes. Attributes are assigned to nodes at startup via GridConfiguration.getUserAttributes() method.

The system adds the following attributes automatically:

• System.getProperties() - All system properties.
• System.getenv(String) - All environment properties.
• org.gridgain.build.ver - GridGain build version.
• org.gridgain.jit.name - Name of JIT compiler used.
• org.gridgain.net.itf.name - Name of network interface.
• org.gridgain.user.name - Operating system user name.
• org.gridgain.grid.name - Grid name (see Grid.getName()).
• spiName.org.gridgain.spi.class - SPI implementation class for every SPI, where spiName is the name of the SPI (see GridSpi.getName().
• spiName.org.gridgain.spi.ver - SPI version for every SPI, where spiName is the name of the SPI (see GridSpi.getName().

Note that attributes cannot be changed at runtime.

Type Parameters:

T - Attribute Type.

Returns:

All node attributes.