com.hazelcast.aws

Class AwsDiscoveryStrategyFactory

java.lang.Object

com.hazelcast.aws.AwsDiscoveryStrategyFactory

All Implemented Interfaces:

DiscoveryStrategyFactory

public class AwsDiscoveryStrategyFactory
extends Object
implements DiscoveryStrategyFactory

Factory class which returns AwsDiscoveryStrategy to Discovery SPI

Nested Class Summary

Nested classes/interfaces inherited from interface com.hazelcast.spi.discovery.DiscoveryStrategyFactory

DiscoveryStrategyFactory.DiscoveryStrategyLevel

Constructor Summary

Constructors

Constructor and Description
AwsDiscoveryStrategyFactory()

Method Summary

Modifier and Type	Method and Description
DiscoveryStrategyFactory.DiscoveryStrategyLevel	discoveryStrategyLevel() Level of the discovery strategy.
Collection<PropertyDefinition>	getConfigurationProperties() Returns a set of the expected configuration properties.
Class<? extends DiscoveryStrategy>	getDiscoveryStrategyType() Returns the type of the DiscoveryStrategy itself.
boolean	isAutoDetectionApplicable() Checks if Hazelcast is running on an AWS EC2 instance.
DiscoveryStrategy	newDiscoveryStrategy(DiscoveryNode discoveryNode, ILogger logger, Map<String,Comparable> properties) Instantiates a new instance of the DiscoveryStrategy with the given configuration properties.

Methods inherited from class java.lang.Object

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

Constructor Detail

AwsDiscoveryStrategyFactory

public AwsDiscoveryStrategyFactory()

Method Detail

getDiscoveryStrategyType

public Class<? extends DiscoveryStrategy> getDiscoveryStrategyType()

Description copied from interface: DiscoveryStrategyFactory

Returns the type of the DiscoveryStrategy itself.

Specified by:

getDiscoveryStrategyType in interface DiscoveryStrategyFactory

Returns:

the type of the discovery strategy

newDiscoveryStrategy

public DiscoveryStrategy newDiscoveryStrategy(DiscoveryNode discoveryNode,
                                              ILogger logger,
                                              Map<String,Comparable> properties)

Description copied from interface: DiscoveryStrategyFactory

Instantiates a new instance of the DiscoveryStrategy with the given configuration properties. The provided HazelcastInstance can be used to register instances in a service registry whenever the discovery strategy is started.

Specified by:

newDiscoveryStrategy in interface DiscoveryStrategyFactory

Parameters:

discoveryNode - the current local DiscoveryNode, representing the local connection information if running on a Hazelcast member, otherwise on Hazelcast clients always null

logger - the logger instance

properties - the properties parsed from the configuration

Returns:

a new instance of the discovery strategy

getConfigurationProperties

public Collection<PropertyDefinition> getConfigurationProperties()

Description copied from interface: DiscoveryStrategyFactory

Returns a set of the expected configuration properties. These properties contain information about the value type of the property, if it is required and a possible validator to automatically test and convert values from the XML configuration.

Specified by:

getConfigurationProperties in interface DiscoveryStrategyFactory

Returns:

a set of expected configuration properties

isAutoDetectionApplicable

public boolean isAutoDetectionApplicable()

Checks if Hazelcast is running on an AWS EC2 instance.

Note that this method returns false for any ECS environment, since currently there is no way to auto-configure Hazelcast network interfaces (required for ECS).

To check if Hazelcast is running on EC2, we first check that the machine uuid starts with "ec2" or "EC2". There is a small chance that a non-AWS machine has uuid starting with the mentioned prefix. That is why, to be sure, we make an API call to a local, non-routable address http://169.254.169.254/latest/dynamic/instance-identity/. Finally, we also check if an IAM Role is attached to the EC2 instance, because without any IAM Role the Hazelcast AWS discovery won't work.

Specified by:

isAutoDetectionApplicable in interface DiscoveryStrategyFactory

Returns:

true if running on EC2 Instance which has an IAM Role attached

See Also:

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/identify_ec2_instances.html

discoveryStrategyLevel

public DiscoveryStrategyFactory.DiscoveryStrategyLevel discoveryStrategyLevel()

Description copied from interface: DiscoveryStrategyFactory

Level of the discovery strategy.

Specified by:

discoveryStrategyLevel in interface DiscoveryStrategyFactory