Package org.apache.catalina.tribes.group
Class GroupChannel
java.lang.Object
org.apache.catalina.tribes.group.ChannelInterceptorBase
org.apache.catalina.tribes.group.GroupChannel
- All Implemented Interfaces:
MBeanRegistration,Channel,ChannelInterceptor,GroupChannelMBean,Heartbeat,JmxChannel,ManagedChannel,MembershipListener
public class GroupChannel
extends ChannelInterceptorBase
implements ManagedChannel, JmxChannel, GroupChannelMBean
The default implementation of a Channel.
The GroupChannel manages the replication channel. It coordinates message being sent and received with membership announcements. The channel has an chain of interceptors that can modify the message or perform other logic.
It manages a complete group, both membership and replication.
The GroupChannel manages the replication channel. It coordinates message being sent and received with membership announcements. The channel has an chain of interceptors that can modify the message or perform other logic.
It manages a complete group, both membership and replication.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionclassTitle: Internal heartbeat runnablestatic classAn iterator to loop through the interceptors in a channel.Nested classes/interfaces inherited from interface org.apache.catalina.tribes.ChannelInterceptor
ChannelInterceptor.InterceptorEvent -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected final List<ChannelListener>A list of channel listeners that subscribe to incoming messagesprotected final ChannelCoordinatorTheChannelCoordinatorcoordinates the bottom layer components:
- MembershipService
- ChannelSender
- ChannelReceiverprotected booleanFlag to determine if the channel manages its own heartbeat If set to true, the channel will start a local thread for the heart beat.protected ScheduledFuture<?>Internal heartbeat futureprotected longIfheartbeat == truethen how often do we want this heartbeat to run.protected ChannelInterceptorThe first interceptor in the interceptor stack.protected final List<MembershipListener>A list of membership listeners that subscribe to membership announcementsprotected ScheduledFuture<?>protected Stringthe name of this channel.protected booleanIf set to true, the GroupChannel will check to make sure thatprotected booleanprotected static final StringManagerprotected ScheduledExecutorServiceExecutor service.Fields inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase
optionFlagFields inherited from interface org.apache.catalina.tribes.Channel
DEFAULT, MBR_RX_SEQ, MBR_TX_SEQ, SEND_OPTIONS_ASYNCHRONOUS, SEND_OPTIONS_BYTE_MESSAGE, SEND_OPTIONS_DEFAULT, SEND_OPTIONS_MULTICAST, SEND_OPTIONS_SECURE, SEND_OPTIONS_SYNCHRONIZED_ACK, SEND_OPTIONS_UDP, SEND_OPTIONS_USE_ACK, SND_RX_SEQ, SND_TX_SEQ -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoidaddChannelListener(ChannelListener channelListener) Add a channel listener, this is a callback object when messages are received.voidaddInterceptor(ChannelInterceptor interceptor) Adds an interceptor to the stack for message processing.voidaddMembershipListener(MembershipListener membershipListener) Add a membership listener, will get notified when a new member joins, leaves or crashes.protected voidValidates the option flags that each interceptor is using and reports an error if two interceptor share the same flag.returns the channel receiverreturns the channel senderReturns the first interceptor of the stack.booleanlongReturns the interceptor stackReturn the jmx domain which this channel is registered.Return the jmx prefix which will be used with channel ObjectName.Returns the membership servicegetName()Return the name of this channel.booleanReturn executor that can be used for utility tasks.voidSends a heartbeat through the interceptor stack.
Invoke this method from the application on a periodic basis if you have turned off internal heartbeatschannel.setHeartbeat(false)booleanIf set to true, this channel is registered with jmx.voidmemberAdded(Member member) memberAdded gets invoked by the interceptor below the channel and the channel will broadcast it to the membership listenersvoidmemberDisappeared(Member member) memberDisappeared gets invoked by the interceptor below the channel and the channel will broadcast it to the membership listenersvoidCallback from the interceptor stack.voidvoidpostRegister(Boolean registrationDone) voidpreRegister(MBeanServer server, ObjectName name) voidremoveChannelListener(ChannelListener channelListener) Remove a channel listener, listeners are removed based onObject.hashCode()andObject.equals(Object).voidremoveMembershipListener(MembershipListener membershipListener) Remove a membership listener, listeners are removed based onObject.hashCode()andObject.equals(Object).send(Member[] destination, Serializable msg, int options) Send a message to one or more members in the clustersend(Member[] destination, Serializable msg, int options, ErrorHandler handler) Send a message to one or more members in the clusterprotected voidsendNoRpcChannelReply(RpcMessage msg, Member destination) Sends aNoRpcChannelReplymessage to a member
This method gets invoked by the channel if an RPC message comes in and no channel listener accepts the message.voidsetChannelReceiver(ChannelReceiver clusterReceiver) Sets the channel receivervoidsetChannelSender(ChannelSender clusterSender) Sets the channel sendervoidsetHeartbeat(boolean heartbeat) Enables or disables local heartbeat. ifsetHeartbeat(true)is invoked then the channel will start an internal thread to invokeChannel.heartbeat()everygetHeartbeatSleeptimemillisecondsvoidsetHeartbeatSleeptime(long heartbeatSleeptime) Configure local heartbeat sleep time
Only used whengetHeartbeat()==truevoidsetJmxDomain(String jmxDomain) Set the jmx domain which this channel should be registered.voidsetJmxEnabled(boolean jmxEnabled) If set to true, this channel is registered with jmx.voidsetJmxPrefix(String jmxPrefix) Set the jmx prefix which will be used with channel ObjectName.voidsetMembershipService(MembershipService membershipService) Sets the membership servicevoidSet the name of this channelvoidsetOptionCheck(boolean optionCheck) Enables/disables the option check
Setting this to true, will make the GroupChannel perform a conflict check on the interceptors.protected voidSets up the default implementation interceptor stack if no interceptors have been addedvoidsetUtilityExecutor(ScheduledExecutorService utilityExecutor) Set the executor that can be used for utility tasks.voidstart(int svc) Starts up the channel.protected voidvoidstop(int svc) Shuts down the channel.Methods inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase
fireInterceptorEvent, getChannel, getLocalMember, getMember, getMembers, getNext, getOptionFlag, getPrevious, hasMembers, okToProcess, sendMessage, setChannel, setNext, setOptionFlag, setPreviousMethods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods inherited from interface org.apache.catalina.tribes.Channel
getLocalMember, getMember, getMembers, hasMembersMethods inherited from interface org.apache.catalina.tribes.group.GroupChannelMBean
getLocalMember, getMembers, hasMembers
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Field Details
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heartbeat
protected boolean heartbeatFlag to determine if the channel manages its own heartbeat If set to true, the channel will start a local thread for the heart beat. -
heartbeatSleeptime
protected long heartbeatSleeptimeIfheartbeat == truethen how often do we want this heartbeat to run. The default value is 5000 milliseconds. -
heartbeatFuture
Internal heartbeat future -
monitorFuture
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coordinator
TheChannelCoordinatorcoordinates the bottom layer components:
- MembershipService
- ChannelSender
- ChannelReceiver -
interceptors
The first interceptor in the interceptor stack. The interceptors are chained in a linked list, so we only need a reference to the first one -
membershipListeners
A list of membership listeners that subscribe to membership announcements -
channelListeners
A list of channel listeners that subscribe to incoming messages -
optionCheck
protected boolean optionCheckIf set to true, the GroupChannel will check to make sure that -
name
the name of this channel. -
utilityExecutor
Executor service. -
ownExecutor
protected boolean ownExecutor
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Constructor Details
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GroupChannel
public GroupChannel()Creates a GroupChannel. This constructor will also add the first interceptor in the GroupChannel.
The first interceptor is always the channel itself.
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Method Details
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addInterceptor
Description copied from interface:ChannelAdds an interceptor to the stack for message processing. Interceptors are ordered in the way they are added.
Will result in an interceptor stack like this:channel.addInterceptor(A); channel.addInterceptor(C); channel.addInterceptor(B);A -> C -> BThe complete stack will look like this:
Channel -> A -> C -> B -> ChannelCoordinator- Specified by:
addInterceptorin interfaceChannel- Parameters:
interceptor- ChannelInterceptorBase
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heartbeat
public void heartbeat()Sends a heartbeat through the interceptor stack.
Invoke this method from the application on a periodic basis if you have turned off internal heartbeatschannel.setHeartbeat(false)- Specified by:
heartbeatin interfaceChannel- Specified by:
heartbeatin interfaceChannelInterceptor- Specified by:
heartbeatin interfaceHeartbeat- Overrides:
heartbeatin classChannelInterceptorBase- See Also:
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send
Description copied from interface:ChannelSend a message to one or more members in the cluster- Specified by:
sendin interfaceChannel- Specified by:
sendin interfaceGroupChannelMBean- Parameters:
destination- Member[] - the destinations, cannot be null or zero length, the reason for that is that a membership change can occur and at that time the application is uncertain what group the message actually got sent to.msg- Serializable - the message to send, has to be serializable, or aByteMessageto send a pure byte arrayoptions- int - sender options, see class documentation for each interceptor that is configured in order to trigger interceptors- Returns:
- a unique Id that identifies the message that is sent
- Throws:
ChannelException- if a serialization error happens.- See Also:
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send
public UniqueId send(Member[] destination, Serializable msg, int options, ErrorHandler handler) throws ChannelException Description copied from interface:ChannelSend a message to one or more members in the cluster- Specified by:
sendin interfaceChannel- Specified by:
sendin interfaceGroupChannelMBean- Parameters:
destination- Member[] - the destinations, null or zero length means allmsg- ClusterMessage - the message to sendoptions- int - sender options, see class documentationhandler- ErrorHandler - handle errors through a callback, rather than throw it- Returns:
- a unique Id that identifies the message that is sent
- Throws:
ChannelException- - if a serialization error happens.
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messageReceived
Callback from the interceptor stack.
When a message is received from a remote node, this method will be invoked by the previous interceptor.
This method can also be used to send a message to other components within the same application, but its an extreme case, and you're probably better off doing that logic between the applications itself.- Specified by:
messageReceivedin interfaceChannelInterceptor- Overrides:
messageReceivedin classChannelInterceptorBase- Parameters:
msg- ChannelMessage
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sendNoRpcChannelReply
Sends aNoRpcChannelReplymessage to a member
This method gets invoked by the channel if an RPC message comes in and no channel listener accepts the message. This avoids timeout- Parameters:
msg- RpcMessagedestination- Member - the destination for the reply
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memberAdded
memberAdded gets invoked by the interceptor below the channel and the channel will broadcast it to the membership listeners- Specified by:
memberAddedin interfaceMembershipListener- Overrides:
memberAddedin classChannelInterceptorBase- Parameters:
member- Member - the new member
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memberDisappeared
memberDisappeared gets invoked by the interceptor below the channel and the channel will broadcast it to the membership listeners- Specified by:
memberDisappearedin interfaceMembershipListener- Overrides:
memberDisappearedin classChannelInterceptorBase- Parameters:
member- Member - the member that left or crashed- See Also:
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setupDefaultStack
Sets up the default implementation interceptor stack if no interceptors have been added- Throws:
ChannelException- Cluster error
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checkOptionFlags
Validates the option flags that each interceptor is using and reports an error if two interceptor share the same flag.- Throws:
ChannelException- Error with option flag
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start
Description copied from interface:ChannelInterceptorStarts up the channel. This can be called multiple times for individual services to start The svc parameter can be the logical or value of any constants- Specified by:
startin interfaceChannel- Specified by:
startin interfaceChannelInterceptor- Specified by:
startin interfaceGroupChannelMBean- Overrides:
startin classChannelInterceptorBase- Parameters:
svc- one of:- Channel.DEFAULT - will start all services
- Channel.MBR_RX_SEQ - starts the membership receiver
- Channel.MBR_TX_SEQ - starts the membership broadcaster
- Channel.SND_TX_SEQ - starts the replication transmitter
- Channel.SND_RX_SEQ - starts the replication receiver
- Throws:
ChannelException- if a startup error occurs or the service is already started.- See Also:
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startHeartbeat
protected void startHeartbeat() -
stop
Description copied from interface:ChannelInterceptorShuts down the channel. This can be called multiple times for individual services to shutdown The svc parameter can be the logical or value of any constants- Specified by:
stopin interfaceChannel- Specified by:
stopin interfaceChannelInterceptor- Specified by:
stopin interfaceGroupChannelMBean- Overrides:
stopin classChannelInterceptorBase- Parameters:
svc- one of:- Channel.DEFAULT - will shutdown all services
- Channel.MBR_RX_SEQ - stops the membership receiver
- Channel.MBR_TX_SEQ - stops the membership broadcaster
- Channel.SND_TX_SEQ - stops the replication transmitter
- Channel.SND_RX_SEQ - stops the replication receiver
- Throws:
ChannelException- if a startup error occurs or the service is already started.- See Also:
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getFirstInterceptor
Returns the first interceptor of the stack. Useful for traversal.- Returns:
- ChannelInterceptor
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getUtilityExecutor
Description copied from interface:ChannelReturn executor that can be used for utility tasks.- Specified by:
getUtilityExecutorin interfaceChannel- Returns:
- the executor
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setUtilityExecutor
Description copied from interface:ChannelSet the executor that can be used for utility tasks.- Specified by:
setUtilityExecutorin interfaceChannel- Parameters:
utilityExecutor- the executor
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getChannelReceiver
Description copied from interface:ManagedChannelreturns the channel receiver- Specified by:
getChannelReceiverin interfaceManagedChannel- Returns:
- ChannelReceiver
- See Also:
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getChannelSender
Description copied from interface:ManagedChannelreturns the channel sender- Specified by:
getChannelSenderin interfaceManagedChannel- Returns:
- ChannelSender
- See Also:
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getMembershipService
Description copied from interface:ManagedChannelReturns the membership service- Specified by:
getMembershipServicein interfaceManagedChannel- Returns:
- MembershipService
- See Also:
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setChannelReceiver
Description copied from interface:ManagedChannelSets the channel receiver- Specified by:
setChannelReceiverin interfaceManagedChannel- Parameters:
clusterReceiver- ChannelReceiver- See Also:
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setChannelSender
Description copied from interface:ManagedChannelSets the channel sender- Specified by:
setChannelSenderin interfaceManagedChannel- Parameters:
clusterSender- ChannelSender- See Also:
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setMembershipService
Description copied from interface:ManagedChannelSets the membership service- Specified by:
setMembershipServicein interfaceManagedChannel- Parameters:
membershipService- MembershipService- See Also:
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addMembershipListener
Description copied from interface:ChannelAdd a membership listener, will get notified when a new member joins, leaves or crashes.If the membership listener implements the Heartbeat interface the
heartbeat()method will be invoked when the heartbeat runs on the channel- Specified by:
addMembershipListenerin interfaceChannel- Specified by:
addMembershipListenerin interfaceGroupChannelMBean- Parameters:
membershipListener- MembershipListener- See Also:
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removeMembershipListener
Description copied from interface:ChannelRemove a membership listener, listeners are removed based onObject.hashCode()andObject.equals(Object).- Specified by:
removeMembershipListenerin interfaceChannel- Specified by:
removeMembershipListenerin interfaceGroupChannelMBean- Parameters:
membershipListener- MembershipListener- See Also:
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addChannelListener
Description copied from interface:ChannelAdd a channel listener, this is a callback object when messages are received.If the channel listener implements the Heartbeat interface the
heartbeat()method will be invoked when the heartbeat runs on the channel- Specified by:
addChannelListenerin interfaceChannel- Specified by:
addChannelListenerin interfaceGroupChannelMBean- Parameters:
channelListener- ChannelListener- See Also:
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removeChannelListener
Description copied from interface:ChannelRemove a channel listener, listeners are removed based onObject.hashCode()andObject.equals(Object).- Specified by:
removeChannelListenerin interfaceChannel- Specified by:
removeChannelListenerin interfaceGroupChannelMBean- Parameters:
channelListener- ChannelListener- See Also:
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getInterceptors
Description copied from interface:ManagedChannelReturns the interceptor stack- Specified by:
getInterceptorsin interfaceManagedChannel- Returns:
- Iterator
- See Also:
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setOptionCheck
public void setOptionCheck(boolean optionCheck) Enables/disables the option check
Setting this to true, will make the GroupChannel perform a conflict check on the interceptors. If two interceptors are using the same option flag and throw an error upon start.- Parameters:
optionCheck- boolean
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setHeartbeatSleeptime
public void setHeartbeatSleeptime(long heartbeatSleeptime) Configure local heartbeat sleep time
Only used whengetHeartbeat()==true- Parameters:
heartbeatSleeptime- long - time in milliseconds to sleep between heartbeats
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setHeartbeat
public void setHeartbeat(boolean heartbeat) Enables or disables local heartbeat. ifsetHeartbeat(true)is invoked then the channel will start an internal thread to invokeChannel.heartbeat()everygetHeartbeatSleeptimemilliseconds- Specified by:
setHeartbeatin interfaceChannel- Parameters:
heartbeat- boolean- See Also:
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getOptionCheck
public boolean getOptionCheck()- Specified by:
getOptionCheckin interfaceGroupChannelMBean
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getHeartbeat
public boolean getHeartbeat()- Specified by:
getHeartbeatin interfaceGroupChannelMBean
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getHeartbeatSleeptime
public long getHeartbeatSleeptime()- Specified by:
getHeartbeatSleeptimein interfaceGroupChannelMBean- Returns:
- the sleep time in milliseconds that the internal heartbeat will sleep in between invocations of
Channel.heartbeat()
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getName
Description copied from interface:ChannelReturn the name of this channel. -
setName
Description copied from interface:ChannelSet the name of this channel -
isJmxEnabled
public boolean isJmxEnabled()Description copied from interface:JmxChannelIf set to true, this channel is registered with jmx.- Specified by:
isJmxEnabledin interfaceJmxChannel- Returns:
- true if this channel will be registered with jmx.
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setJmxEnabled
public void setJmxEnabled(boolean jmxEnabled) Description copied from interface:JmxChannelIf set to true, this channel is registered with jmx.- Specified by:
setJmxEnabledin interfaceJmxChannel- Parameters:
jmxEnabled- set to true if this channel should be registered with jmx.
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getJmxDomain
Description copied from interface:JmxChannelReturn the jmx domain which this channel is registered.- Specified by:
getJmxDomainin interfaceJmxChannel- Returns:
- jmxDomain
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setJmxDomain
Description copied from interface:JmxChannelSet the jmx domain which this channel should be registered.- Specified by:
setJmxDomainin interfaceJmxChannel- Parameters:
jmxDomain- The jmx domain which this channel should be registered.
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getJmxPrefix
Description copied from interface:JmxChannelReturn the jmx prefix which will be used with channel ObjectName.- Specified by:
getJmxPrefixin interfaceJmxChannel- Returns:
- jmxPrefix
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setJmxPrefix
Description copied from interface:JmxChannelSet the jmx prefix which will be used with channel ObjectName.- Specified by:
setJmxPrefixin interfaceJmxChannel- Parameters:
jmxPrefix- The jmx prefix which will be used with channel ObjectName.
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preRegister
- Specified by:
preRegisterin interfaceMBeanRegistration- Throws:
Exception
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postRegister
- Specified by:
postRegisterin interfaceMBeanRegistration
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preDeregister
- Specified by:
preDeregisterin interfaceMBeanRegistration- Throws:
Exception
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postDeregister
public void postDeregister()- Specified by:
postDeregisterin interfaceMBeanRegistration
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