Package com.hazelcast.gcp

Class GcpDiscoveryStrategyFactory

java.lang.Object

com.hazelcast.gcp.GcpDiscoveryStrategyFactory

All Implemented Interfaces:

DiscoveryStrategyFactory

public class GcpDiscoveryStrategyFactory
extends Object
implements DiscoveryStrategyFactory

Factory class which returns GcpDiscoveryStrategy to Discovery SPI.

Nested Class Summary

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

DiscoveryStrategyFactory.DiscoveryStrategyLevel

Constructor Summary

Constructors

Constructor	Description
GcpDiscoveryStrategyFactory()

Method Summary

Modifier and Type	Method	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 GCP.
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 Details

GcpDiscoveryStrategyFactory

public GcpDiscoveryStrategyFactory()

Method Details

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 GCP.

To check if Hazelcast is running on GCP, we first check whether the internal DNS is configured for "google.internal" in either "/etc/resolv.conf" or "/etc/hosts". Such an approach is not officially documented but seems like a good enough heuristic to detect a GCP Compute VM Instance. Since it's not the official method, we still need to make an API call to "metadata.google.internal" which will resolve to a local, non-routable address http://169.254.169.254/. Finally, we check if there is a service account attached for this instance because without a service account Hazelcast GCP discovery will not work.

Specified by:

isAutoDetectionApplicable in interface DiscoveryStrategyFactory

Returns:

true if running on GCP Instance which has a service account attached

See Also:

• GCP Managing Instances

discoveryStrategyLevel

public DiscoveryStrategyFactory.DiscoveryStrategyLevel discoveryStrategyLevel()

Description copied from interface: DiscoveryStrategyFactory

Level of the discovery strategy.

Specified by:

discoveryStrategyLevel in interface DiscoveryStrategyFactory