pl.edu.agh.age.services.topology.internal

Class DefaultTopologyService

java.lang.Object

pl.edu.agh.age.services.topology.internal.DefaultTopologyService

All Implemented Interfaces:

org.springframework.context.Lifecycle, org.springframework.context.Phased, org.springframework.context.SmartLifecycle, TopologyService

@Named
public final class DefaultTopologyService
extends java.lang.Object
implements org.springframework.context.SmartLifecycle, TopologyService

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	DefaultTopologyService.DistributedMessageListener
private static class	DefaultTopologyService.Event Events that can occur in the service.
private static class	DefaultTopologyService.ExceptionHandler
private static class	DefaultTopologyService.State States of the topology service.
private class	DefaultTopologyService.TopologyTypeChangeListener

Field Summary

Fields

Modifier and Type	Field and Description
private @Nullable org.jgrapht.Graph<java.lang.String,org.jgrapht.graph.DefaultEdge>	cachedTopology
private TopologyProcessor	currentTopologyProcessor
private DiscoveryService	discoveryService
private EventBus	eventBus
private ListeningScheduledExecutorService	executorService
private NodeIdentityService	identityService
private @Nullable java.lang.String	listenerKey
private static org.slf4j.Logger	logger
private boolean	master
private IMap<java.lang.String,java.lang.Object>	runtimeConfig
private StateMachineService<DefaultTopologyService.State,DefaultTopologyService.Event>	service
private ITopic<TopologyMessage>	topic
private java.util.List<TopologyProcessor>	topologyProcessors

Constructor Summary

Constructors

Constructor and Description
DefaultTopologyService(DiscoveryService discoveryService, NodeIdentityService identityService, EventBus eventBus, java.util.List<TopologyProcessor> topologyProcessors, HazelcastInstance hazelcastInstance)

Method Summary

Modifier and Type	Method and Description
private java.util.Set<NodeDescriptor>	allNodes()
private void	electMaster(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm) Simple master selection.
private @Nullable org.jgrapht.Graph<java.lang.String,org.jgrapht.graph.DefaultEdge>	getCurrentTopologyGraph()
int	getPhase()
private java.util.Optional<TopologyProcessor>	getTopologyProcessorWithName(java.lang.String processorName)
void	handleNodeDestroyedEvent(NodeDestroyedEvent event)
boolean	hasTopology()
private void	internalStart(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm)
private void	internalStop(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm)
boolean	isAutoStartup()
boolean	isLocalNodeMaster()
boolean	isRunning()
java.util.Optional<java.lang.String>	masterId()
void	membershipChange(DiscoveryEvent event)
java.util.Set<java.lang.String>	neighbours() Returns a set of neighbours of the current node.
void	start()
void	stop()
void	stop(java.lang.Runnable callback)
private void	topologyChanged(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm) Called when topology has changed: new member member removal type changed
private void	topologyConfigured(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> stateEventFSM) Called on all nodes when the topology has been configured by master.
java.util.Optional<org.jgrapht.Graph<java.lang.String,org.jgrapht.graph.DefaultEdge>>	topologyGraph() Returns the current topology graph.
java.util.Optional<java.lang.String>	topologyType()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static final org.slf4j.Logger logger

executorService

private final ListeningScheduledExecutorService executorService

discoveryService

private final DiscoveryService discoveryService

identityService

private final NodeIdentityService identityService

eventBus

private final EventBus eventBus

topologyProcessors

private final java.util.List<TopologyProcessor> topologyProcessors

runtimeConfig

private final IMap<java.lang.String,java.lang.Object> runtimeConfig

topic

private final ITopic<TopologyMessage> topic

service

private final StateMachineService<DefaultTopologyService.State,DefaultTopologyService.Event> service

currentTopologyProcessor

private TopologyProcessor currentTopologyProcessor

master

private boolean master

listenerKey

private @Nullable java.lang.String listenerKey

cachedTopology

private @Nullable org.jgrapht.Graph<java.lang.String,org.jgrapht.graph.DefaultEdge> cachedTopology

Constructor Detail

DefaultTopologyService

@Inject
public DefaultTopologyService(DiscoveryService discoveryService,
                                      NodeIdentityService identityService,
                                      EventBus eventBus,
                                      java.util.List<TopologyProcessor> topologyProcessors,
                                      HazelcastInstance hazelcastInstance)

Method Detail

isAutoStartup

public boolean isAutoStartup()

Specified by:

isAutoStartup in interface org.springframework.context.SmartLifecycle

stop

public void stop(java.lang.Runnable callback)

Specified by:

stop in interface org.springframework.context.SmartLifecycle

start

public void start()

Specified by:

start in interface org.springframework.context.Lifecycle

stop

public void stop()

Specified by:

stop in interface org.springframework.context.Lifecycle

isRunning

public boolean isRunning()

Specified by:

isRunning in interface org.springframework.context.Lifecycle

getPhase

public int getPhase()

Specified by:

getPhase in interface org.springframework.context.Phased

internalStart

private void internalStart(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm)

internalStop

private void internalStop(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm)

electMaster

private void electMaster(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm)

Simple master selection. We rely on Hazelcast, so we just need to perform local, deterministic selection.

In this case we selects the node with the largest nodeId.

topologyChanged

private void topologyChanged(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> fsm)

Called when topology has changed:

• new member
• member removal
• type changed

Executed only on master.

topologyConfigured

private void topologyConfigured(FSM<DefaultTopologyService.State,DefaultTopologyService.Event> stateEventFSM)

Called on all nodes when the topology has been configured by master.

getTopologyProcessorWithName

private java.util.Optional<TopologyProcessor> getTopologyProcessorWithName(java.lang.String processorName)

getCurrentTopologyGraph

private @Nullable org.jgrapht.Graph<java.lang.String,org.jgrapht.graph.DefaultEdge> getCurrentTopologyGraph()

masterId

public java.util.Optional<java.lang.String> masterId()

Specified by:

masterId in interface TopologyService

isLocalNodeMaster

public boolean isLocalNodeMaster()

Specified by:

isLocalNodeMaster in interface TopologyService

hasTopology

public boolean hasTopology()

Specified by:

hasTopology in interface TopologyService

topologyGraph

public java.util.Optional<org.jgrapht.Graph<java.lang.String,org.jgrapht.graph.DefaultEdge>> topologyGraph()

Description copied from interface: TopologyService

Returns the current topology graph.

Specified by:

topologyGraph in interface TopologyService

Returns:

an Optional containing the topology graph or empty when no topology was set.

topologyType

public java.util.Optional<java.lang.String> topologyType()

Specified by:

topologyType in interface TopologyService

neighbours

public java.util.Set<java.lang.String> neighbours()

Description copied from interface: TopologyService

Returns a set of neighbours of the current node.

Specified by:

neighbours in interface TopologyService

Returns:

set of String, possibly empty when there is no topology or the node has no neighbours.

membershipChange

public void membershipChange(DiscoveryEvent event)

allNodes

private java.util.Set<NodeDescriptor> allNodes()

handleNodeDestroyedEvent

public void handleNodeDestroyedEvent(NodeDestroyedEvent event)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object