Module org.eclipse.jetty.server

Package org.eclipse.jetty.server

Class LowResourceMonitor

java.lang.Object

org.eclipse.jetty.util.component.AbstractLifeCycle

org.eclipse.jetty.util.component.ContainerLifeCycle

org.eclipse.jetty.server.LowResourceMonitor

All Implemented Interfaces:

org.eclipse.jetty.util.component.Container, org.eclipse.jetty.util.component.Destroyable, org.eclipse.jetty.util.component.Dumpable, org.eclipse.jetty.util.component.Dumpable.DumpableContainer, org.eclipse.jetty.util.component.LifeCycle

@ManagedObject("Monitor for low resource conditions and activate a low resource mode if detected")
public class LowResourceMonitor
extends org.eclipse.jetty.util.component.ContainerLifeCycle

A monitor for low resources, low resources can be detected by:

• ThreadPool.isLowOnThreads() if Connector.getExecutor() is an instance of ThreadPool and setMonitorThreads(boolean) is true.
• If setMaxMemory(long) is non zero then low resources is detected if the JVMs Runtime instance has Runtime.totalMemory() minus Runtime.freeMemory() greater than getMaxMemory()

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	LowResourceMonitor.ConnectorsThreadPoolLowResourceCheck
static interface	LowResourceMonitor.LowResourceCheck
class	LowResourceMonitor.MainThreadPoolLowResourceCheck
class	LowResourceMonitor.MaxConnectionsLowResourceCheck
class	LowResourceMonitor.MemoryLowResourceCheck

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

org.eclipse.jetty.util.component.AbstractLifeCycle.AbstractLifeCycleListener, org.eclipse.jetty.util.component.AbstractLifeCycle.StopException

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

org.eclipse.jetty.util.component.Container.InheritedListener, org.eclipse.jetty.util.component.Container.Listener

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

org.eclipse.jetty.util.component.Dumpable.DumpableContainer

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

org.eclipse.jetty.util.component.LifeCycle.Listener

Field Summary

Fields

Modifier and Type	Field	Description
protected final Server	_server

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
LowResourceMonitor(Server server)

Method Summary

Modifier and Type	Method	Description
void	addLowResourceCheck(LowResourceMonitor.LowResourceCheck lowResourceCheck)
protected void	clearLowResources()
protected void	doStart()
protected void	doStop()
protected boolean	enableLowOnResources(boolean expectedValue, boolean newValue)
Set<LowResourceMonitor.LowResourceCheck>	getLowResourceChecks()
int	getLowResourcesIdleTimeout()
String	getLowResourcesReasons()
long	getLowResourcesStarted()
int	getMaxLowResourcesTime()
long	getMaxMemory()
Collection<Connector>	getMonitoredConnectors()
protected Connector[]	getMonitoredOrServerConnectors()
boolean	getMonitorThreads()
int	getPeriod()
String	getReasons()
boolean	isAcceptingInLowResources()
boolean	isLowOnResources()
protected String	low(String reasons, String newReason)
protected void	monitor()
void	setAcceptingInLowResources(boolean acceptingInLowResources)
void	setLowResourceChecks(Set<LowResourceMonitor.LowResourceCheck> lowResourceChecks)
protected void	setLowResources()
void	setLowResourcesIdleTimeout(int lowResourcesIdleTimeoutMS)
protected void	setLowResourcesReasons(String reasons)
void	setLowResourcesStarted(long lowStarted)
void	setMaxLowResourcesTime(int maxLowResourcesTimeMS)
void	setMaxMemory(long maxMemoryBytes)
void	setMonitoredConnectors(Collection<Connector> monitoredConnectors)
void	setMonitorThreads(boolean monitorThreads)
void	setPeriod(int periodMS)
protected void	setReasons(String reasons)

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

addBean, addBean, addEventListener, addManaged, contains, destroy, dump, dump, dump, dumpObjects, dumpStdErr, getBean, getBeans, getBeans, getContainedBeans, getContainedBeans, installBean, installBean, 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, toString

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

dumpSelf

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

isDumpable

Field Details

_server

protected final Server _server

Constructor Details

LowResourceMonitor

public LowResourceMonitor(@Name("server")
 Server server)

Method Details

getMonitorThreads

@ManagedAttribute("True if low available threads status is monitored")
public boolean getMonitorThreads()

setMonitorThreads

public void setMonitorThreads(boolean monitorThreads)

Parameters:

monitorThreads - If true, check connectors executors to see if they are ThreadPool instances that are low on threads.

getReasons

@ManagedAttribute("The reasons the monitored connectors are low on resources")
public String getReasons()

setReasons

protected void setReasons(String reasons)

isLowOnResources

@ManagedAttribute("Are the monitored connectors low on resources?")
public boolean isLowOnResources()

enableLowOnResources

protected boolean enableLowOnResources(boolean expectedValue,
 boolean newValue)

getLowResourcesReasons

@ManagedAttribute("The reason(s) the monitored connectors are low on resources")
public String getLowResourcesReasons()

setLowResourcesReasons

protected void setLowResourcesReasons(String reasons)

getLowResourcesStarted

@ManagedAttribute("Get the timestamp in ms since epoch that low resources state started")
public long getLowResourcesStarted()

setLowResourcesStarted

public void setLowResourcesStarted(long lowStarted)

getMonitoredConnectors

@ManagedAttribute("The monitored connectors. If null then all server connectors are monitored")
public Collection<Connector> getMonitoredConnectors()

setMonitoredConnectors

public void setMonitoredConnectors(Collection<Connector> monitoredConnectors)

Parameters:

monitoredConnectors - The collections of Connectors that should be monitored for low resources.

getMonitoredOrServerConnectors

protected Connector[] getMonitoredOrServerConnectors()

isAcceptingInLowResources

@ManagedAttribute("If false, new connections are not accepted while in low resources")
public boolean isAcceptingInLowResources()

setAcceptingInLowResources

public void setAcceptingInLowResources(boolean acceptingInLowResources)

getPeriod

@ManagedAttribute("The monitor period in ms")
public int getPeriod()

setPeriod

public void setPeriod(int periodMS)

Parameters:

periodMS - The period in ms to monitor for low resources

getLowResourcesIdleTimeout

@ManagedAttribute("The idletimeout in ms to apply to all existing connections when low resources is detected")
public int getLowResourcesIdleTimeout()

setLowResourcesIdleTimeout

public void setLowResourcesIdleTimeout(int lowResourcesIdleTimeoutMS)

Parameters:

lowResourcesIdleTimeoutMS - The timeout in ms to apply to EndPoints when in the low resources state.

getMaxLowResourcesTime

@ManagedAttribute("The maximum time in ms that low resources condition can persist before lowResourcesIdleTimeout is applied to new connections as well as existing connections")
public int getMaxLowResourcesTime()

setMaxLowResourcesTime

public void setMaxLowResourcesTime(int maxLowResourcesTimeMS)

Parameters:

maxLowResourcesTimeMS - The time in milliseconds that a low resource state can persist before the low resource idle timeout is reapplied to all connections

getMaxMemory

@ManagedAttribute("The maximum memory (in bytes) that can be used before low resources is triggered.  Memory used is calculated as (totalMemory-freeMemory).")
public long getMaxMemory()

setMaxMemory

public void setMaxMemory(long maxMemoryBytes)

Parameters:

maxMemoryBytes - The maximum memory in bytes in use before low resources is triggered.

getLowResourceChecks

public Set<LowResourceMonitor.LowResourceCheck> getLowResourceChecks()

setLowResourceChecks

public void setLowResourceChecks(Set<LowResourceMonitor.LowResourceCheck> lowResourceChecks)

addLowResourceCheck

public void addLowResourceCheck(LowResourceMonitor.LowResourceCheck lowResourceCheck)

monitor

protected void monitor()

doStart

protected void doStart()
                throws Exception

Overrides:

doStart in class org.eclipse.jetty.util.component.ContainerLifeCycle

Throws:

Exception

doStop

protected void doStop()
               throws Exception

Overrides:

doStop in class org.eclipse.jetty.util.component.ContainerLifeCycle

Throws:

Exception

setLowResources

protected void setLowResources()

clearLowResources

protected void clearLowResources()

low

protected String low(String reasons,
 String newReason)