Package org.eclipse.jetty.client

Class RoundRobinConnectionPool

java.lang.Object

org.eclipse.jetty.util.component.AbstractLifeCycle

org.eclipse.jetty.util.component.ContainerLifeCycle

org.eclipse.jetty.client.AbstractConnectionPool

org.eclipse.jetty.client.MultiplexConnectionPool

org.eclipse.jetty.client.RoundRobinConnectionPool

All Implemented Interfaces:

Closeable, AutoCloseable, ConnectionPool, Container, Destroyable, Dumpable, Dumpable.DumpableContainer, LifeCycle, Sweeper.Sweepable

@ManagedObject
public class RoundRobinConnectionPool
extends MultiplexConnectionPool

A ConnectionPool that attempts to provide connections using a round-robin algorithm.

The round-robin behavior is almost impossible to achieve for several reasons:

• the server takes different times to serve different requests; if a request takes a long time to be processed by the server, it would be a performance penalty to stall sending requests waiting for that connection to be available - better skip it and try another connection
• connections may be closed by the client or by the server, so it would be a performance penalty to stall sending requests waiting for a new connection to be opened
• thread scheduling on both client and server may temporarily penalize a connection

Do not expect this class to provide connections in a perfect recurring sequence such as c0, c1, ..., cN-1, c0, c1, ..., cN-1, c0, c1, ... because that is impossible to achieve in a real environment. This class will just attempt a best-effort to provide the connections in a sequential order, but most likely the order will be quasi-random.

Applications using this class should pre-create the connections to ensure that they are already opened when the application starts to requests them, otherwise the first connection that is opened may be used multiple times before the others are opened, resulting in a behavior that is more random-like than more round-robin-like (and that confirms that round-robin behavior is almost impossible to achieve).

See Also:

• RandomConnectionPool

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

AbstractLifeCycle.AbstractLifeCycleListener, AbstractLifeCycle.StopException

Nested classes/interfaces inherited from interface org.eclipse.jetty.client.ConnectionPool

ConnectionPool.Factory, ConnectionPool.MaxUsable, ConnectionPool.Multiplexable

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.Container

Container.InheritedListener, Container.Listener

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.Dumpable

Dumpable.DumpableContainer

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.LifeCycle

LifeCycle.Listener

Field Summary

Fields inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

FAILED, STARTED, STARTING, STOPPED, STOPPING

Fields inherited from interface org.eclipse.jetty.util.component.Dumpable

KEY

Constructor Summary

Constructors

Constructor	Description
RoundRobinConnectionPool(HttpDestination destination, int maxConnections, Callback requester)
RoundRobinConnectionPool(HttpDestination destination, int maxConnections, Callback requester, int maxMultiplex)

Method Summary

Methods inherited from class org.eclipse.jetty.client.MultiplexConnectionPool

getMaxMultiplex, getMaxUsageCount, setMaxMultiplex, setMaxUsageCount

Methods inherited from class org.eclipse.jetty.client.AbstractConnectionPool

accept, acquire, acquired, activate, close, deactivate, doStop, dump, getActiveConnectionCount, getConnectionCount, getIdleConnectionCount, getMaxConnectionCount, getMaxDuration, getPendingConnectionCount, idle, isActive, isClosed, isEmpty, isMaximizeConnections, onCreated, preCreateConnections, proceed, release, released, remove, remove, removed, setMaxDuration, setMaximizeConnections, sweep, toString, tryCreate

Methods inherited from class org.eclipse.jetty.util.component.ContainerLifeCycle

addBean, addBean, addEventListener, addManaged, contains, destroy, doStart, dump, dump, dumpObjects, dumpStdErr, getBean, getBeans, getBeans, getContainedBeans, getContainedBeans, isAuto, isManaged, isUnmanaged, manage, removeBean, removeBeans, removeEventListener, setBeans, start, stop, unmanage, updateBean, updateBean, updateBeans, updateBeans

Methods inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

getEventListeners, getState, getState, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, setEventListeners, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.jetty.util.component.Container

getCachedBeans, getEventListeners

Methods inherited from interface org.eclipse.jetty.util.component.Dumpable

dump, dumpSelf

Methods inherited from interface org.eclipse.jetty.util.component.Dumpable.DumpableContainer

isDumpable

Constructor Details

RoundRobinConnectionPool

public RoundRobinConnectionPool(HttpDestination destination,
 int maxConnections,
 Callback requester)

RoundRobinConnectionPool

public RoundRobinConnectionPool(HttpDestination destination,
 int maxConnections,
 Callback requester,
 int maxMultiplex)