Package org.apache.drill.exec.coord

Class ClusterCoordinator

java.lang.Object

org.apache.drill.exec.coord.ClusterCoordinator

All Implemented Interfaces:

AutoCloseable

Direct Known Subclasses:

LocalClusterCoordinator, ZKClusterCoordinator, ZKClusterCoordinator

public abstract class ClusterCoordinator
extends Object
implements AutoCloseable

Pluggable interface built to manage cluster coordination. Allows Drillbit or DrillClient to register its capabilities as well as understand other node's existence and capabilities.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ClusterCoordinator.RegistrationHandle

Field Summary

Fields

Modifier and Type	Field	Description
protected ConcurrentHashMap<DrillbitStatusListener,DrillbitStatusListener>	listeners

Constructor Summary

Constructors

Constructor	Description
ClusterCoordinator()

Method Summary

Modifier and Type	Method	Description
void	addDrillbitStatusListener(DrillbitStatusListener listener)	Register a DrillbitStatusListener.
protected void	drillbitRegistered(Set<CoordinationProtos.DrillbitEndpoint> registeredBits)
protected void	drillbitUnregistered(Set<CoordinationProtos.DrillbitEndpoint> unregisteredBits)	Actions to take when there are a set of new de-active drillbits.
abstract Collection<CoordinationProtos.DrillbitEndpoint>	getAvailableEndpoints()	Get a collection of available Drillbit endpoints, Thread-safe.
abstract Collection<CoordinationProtos.DrillbitEndpoint>	getOnlineEndPoints()	Get a collection of ONLINE drillbit endpoints by excluding the drillbits that are in QUIESCENT state (drillbits that are shutting down).
abstract <V> TransientStore<V>	getOrCreateTransientStore(TransientStoreConfig<V> config)	Returns a store instance with the given configuration.
abstract DistributedSemaphore	getSemaphore(String name, int maximumLeases)
boolean	isDrillbitInState(CoordinationProtos.DrillbitEndpoint endpoint, CoordinationProtos.DrillbitEndpoint.State state)
abstract ClusterCoordinator.RegistrationHandle	register(CoordinationProtos.DrillbitEndpoint data)
void	removeDrillbitStatusListener(DrillbitStatusListener listener)	Unregister a DrillbitStatusListener.
abstract void	start(long millisToWait)	Start the cluster coordinator.
abstract void	unregister(ClusterCoordinator.RegistrationHandle handle)
abstract ClusterCoordinator.RegistrationHandle	update(ClusterCoordinator.RegistrationHandle handle, CoordinationProtos.DrillbitEndpoint.State state)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.AutoCloseable

close

Field Details

listeners

protected ConcurrentHashMap<DrillbitStatusListener,DrillbitStatusListener> listeners

Constructor Details

ClusterCoordinator

public ClusterCoordinator()

Method Details

start

public abstract void start(long millisToWait)
                    throws Exception

Start the cluster coordinator. Millis to wait is

Parameters:

millisToWait - The maximum time to wait before throwing an exception if the cluster coordination service has not successfully started. Use 0 to wait indefinitely.

Throws:

Exception - in case when unable to start coordinator

register

public abstract ClusterCoordinator.RegistrationHandle register(CoordinationProtos.DrillbitEndpoint data)

unregister

public abstract void unregister(ClusterCoordinator.RegistrationHandle handle)

getAvailableEndpoints

public abstract Collection<CoordinationProtos.DrillbitEndpoint> getAvailableEndpoints()

Get a collection of available Drillbit endpoints, Thread-safe. Could be slightly out of date depending on refresh policy.

Returns:

A collection of available endpoints.

getOnlineEndPoints

public abstract Collection<CoordinationProtos.DrillbitEndpoint> getOnlineEndPoints()

Get a collection of ONLINE drillbit endpoints by excluding the drillbits that are in QUIESCENT state (drillbits that are shutting down). Primarily used by the planner to plan queries only on ONLINE drillbits and used by the client during initial connection phase to connect to a drillbit (foreman)

Returns:

A collection of ONLINE endpoints

update

public abstract ClusterCoordinator.RegistrationHandle update(ClusterCoordinator.RegistrationHandle handle,
 CoordinationProtos.DrillbitEndpoint.State state)

getSemaphore

public abstract DistributedSemaphore getSemaphore(String name,
 int maximumLeases)

getOrCreateTransientStore

public abstract <V> TransientStore<V> getOrCreateTransientStore(TransientStoreConfig<V> config)

Returns a store instance with the given configuration. Note that implementor might cache the instance so new instance creation is not guaranteed.

Type Parameters:

V - value type for this store

Parameters:

config - store configuration

drillbitUnregistered

protected void drillbitUnregistered(Set<CoordinationProtos.DrillbitEndpoint> unregisteredBits)

Actions to take when there are a set of new de-active drillbits.

Parameters:

unregisteredBits - set of drillbits to unregister

drillbitRegistered

protected void drillbitRegistered(Set<CoordinationProtos.DrillbitEndpoint> registeredBits)

addDrillbitStatusListener

public void addDrillbitStatusListener(DrillbitStatusListener listener)

Register a DrillbitStatusListener. Note : the listeners are not guaranteed to be called in the order in which they call this method, since all the listeners are in a ConcurrentHashMap.

Parameters:

listener - status listener

removeDrillbitStatusListener

public void removeDrillbitStatusListener(DrillbitStatusListener listener)

Unregister a DrillbitStatusListener.

Parameters:

listener - status listener

isDrillbitInState

public boolean isDrillbitInState(CoordinationProtos.DrillbitEndpoint endpoint,
 CoordinationProtos.DrillbitEndpoint.State state)