com.hazelcast.spi.discovery

Interface DiscoveryStrategyFactory

All Known Implementing Classes:

AwsDiscoveryStrategyFactory, AzureDiscoveryStrategyFactory, GcpDiscoveryStrategyFactory, HazelcastKubernetesDiscoveryStrategyFactory, MulticastDiscoveryStrategyFactory

public interface DiscoveryStrategyFactory

The DiscoveryStrategyFactory is the entry point for strategy vendors. Every DiscoveryStrategy should have its own factory building it. In rare cases (like multiple version support or similar) one factory might return different provider implementations based on certain criteria. It is also up to the DiscoveryStrategyFactory to cache instances and return them in some kind of a Singleton-like fashion.

The defined set of configuration properties describes the existing properties inside of the Hazelcast configuration. It will be used for automatic conversion, type-checking and validation before handing them to the DiscoveryStrategy. This removes a lot of boilerplate from the provider vendor and provides some convenience as well as guarantee to execute the expected configuration checks. The later is especially important because there is no schema support for properties necessary or provided by the provider plugins. Any kind of violation while verification of any type conversion error as well as missing non-optional properties will throw an exception and prevent the node from starting up.

Since:

3.6

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	DiscoveryStrategyFactory.DiscoveryStrategyLevel Level of the discovery strategy.

Method Summary

Modifier and Type	Method and Description
default 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.
default boolean	isAutoDetectionApplicable() Checks whether the given discovery strategy may be applied with no additional config to the environment in which Hazelcast is currently running.
DiscoveryStrategy	newDiscoveryStrategy(DiscoveryNode discoveryNode, ILogger logger, Map<String,Comparable> properties) Instantiates a new instance of the DiscoveryStrategy with the given configuration properties.

Method Detail

getDiscoveryStrategyType

Class<? extends DiscoveryStrategy> getDiscoveryStrategyType()

Returns the type of the DiscoveryStrategy itself.

Returns:

the type of the discovery strategy

newDiscoveryStrategy

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

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.

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

Collection<PropertyDefinition> getConfigurationProperties()

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.

Returns:

a set of expected configuration properties

isAutoDetectionApplicable

default boolean isAutoDetectionApplicable()

Checks whether the given discovery strategy may be applied with no additional config to the environment in which Hazelcast is currently running.

Used by the auto detection mechanism to decide which strategy should be used.

discoveryStrategyLevel

default DiscoveryStrategyFactory.DiscoveryStrategyLevel discoveryStrategyLevel()

Level of the discovery strategy.