Package org.jgroups.protocols.pbcast
Class STATE_TRANSFER
- java.lang.Object
-
- org.jgroups.stack.Protocol
-
- org.jgroups.protocols.pbcast.STATE_TRANSFER
-
- All Implemented Interfaces:
ProcessingQueue.Handler<Address>
public class STATE_TRANSFER extends Protocol implements ProcessingQueue.Handler<Address>
STATE_TRANSFER protocol based on byte array transfer. A state request is sent to a chosen member (coordinator if null). That member makes a copy D of its current digest and asks the application for a copy of its current state S. Then the member returns both S and D to the requester. The requester first sets its digest to D and then returns the state to the application.- Author:
- Bela Ban
- See Also:
STATE
,STATE_SOCK
-
-
Nested Class Summary
Nested Classes Modifier and Type Class Description static class
STATE_TRANSFER.StateHeader
Wraps data for a state request/response.
-
Field Summary
Fields Modifier and Type Field Description protected double
avg_state_size
protected boolean
flushProtocolInStack
protected Address
local_addr
protected java.util.List<Address>
members
protected java.util.concurrent.atomic.LongAdder
num_bytes_sent
protected java.util.concurrent.atomic.LongAdder
num_state_reqs
protected long
start
protected ProcessingQueue<Address>
state_requesters
List of members requesting stateprotected long
stop
protected View
view
protected boolean
waiting_for_state_response
set to true while waiting for a STATE_RSP-
Fields inherited from class org.jgroups.stack.Protocol
after_creation_hook, down_prot, ergonomics, id, log, stack, stats, up_prot
-
-
Constructor Summary
Constructors Constructor Description STATE_TRANSFER()
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
closeBarrierAndSuspendStable()
protected void
closeHoleFor(Address member)
protected Address
determineCoordinator()
Return the first element of members which is not me.java.lang.Object
down(Event evt)
An event is to be sent down the stack.double
getAverageStateSize()
long
getNumberOfStateBytesSent()
long
getNumberOfStateRequests()
protected void
getStateFromApplication(Address requester, Digest digest)
void
handle(Address state_requester)
protected void
handleException(java.lang.Throwable exception)
protected void
handleStateReq(Address requester)
protected void
handleStateRsp(Digest digest, Address sender, byte[] state)
Set the digest and the send the state up to the applicationprotected void
handleViewChange(View v)
void
init()
Called after instance has been created (null constructor) and before protocol is started.protected boolean
isDigestNeeded()
When FLUSH is used we do not need to pass digests between members see JGroups/doc/design/PartialStateTransfer.txt see JGroups/doc/design/FLUSH.txtvoid
openBarrier()
void
openBarrierAndResumeStable()
protected void
punchHoleFor(Address member)
java.util.List<java.lang.Integer>
requiredDownServices()
List of events that are required to be answered by some layer belowvoid
resetStats()
void
resumeStable()
protected void
sendException(Address requester, java.lang.Throwable exception)
void
start()
This method is called on aJChannel.connect(String)
.void
stop()
This method is called on aJChannel.disconnect()
.java.lang.Object
up(Event evt)
An event was received from the protocol below.java.lang.Object
up(Message msg)
A single message was received.-
Methods inherited from class org.jgroups.stack.Protocol
accept, afterCreationHook, destroy, down, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, providedDownServices, providedUpServices, requiredUpServices, resetStatistics, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, statsEnabled, up
-
-
-
-
Field Detail
-
start
protected long start
-
stop
protected long stop
-
num_state_reqs
protected final java.util.concurrent.atomic.LongAdder num_state_reqs
-
num_bytes_sent
protected final java.util.concurrent.atomic.LongAdder num_bytes_sent
-
avg_state_size
protected double avg_state_size
-
local_addr
protected Address local_addr
-
view
protected volatile View view
-
members
protected final java.util.List<Address> members
-
state_requesters
protected final ProcessingQueue<Address> state_requesters
List of members requesting state
-
waiting_for_state_response
protected volatile boolean waiting_for_state_response
set to true while waiting for a STATE_RSP
-
flushProtocolInStack
protected boolean flushProtocolInStack
-
-
Method Detail
-
getNumberOfStateRequests
public long getNumberOfStateRequests()
-
getNumberOfStateBytesSent
public long getNumberOfStateBytesSent()
-
getAverageStateSize
public double getAverageStateSize()
-
requiredDownServices
public java.util.List<java.lang.Integer> requiredDownServices()
Description copied from class:Protocol
List of events that are required to be answered by some layer below- Overrides:
requiredDownServices
in classProtocol
-
resetStats
public void resetStats()
- Overrides:
resetStats
in classProtocol
-
init
public void init() throws java.lang.Exception
Description copied from class:Protocol
Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.
-
start
public void start() throws java.lang.Exception
Description copied from class:Protocol
This method is called on aJChannel.connect(String)
. Starts work. Protocols are connected and queues are ready to receive events. Will be called from bottom to top. This call will replace the START and START_OK events.- Overrides:
start
in classProtocol
- Throws:
java.lang.Exception
- Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, soJChannel.connect(String)
will throw an exception
-
stop
public void stop()
Description copied from class:Protocol
This method is called on aJChannel.disconnect()
. Stops work (e.g. by closing multicast socket). Will be called from top to bottom. This means that at the time of the method invocation the neighbor protocol below is still working. This method will replace the STOP, STOP_OK, CLEANUP and CLEANUP_OK events. The ProtocolStack guarantees that when this method is called all messages in the down queue will have been flushed
-
closeBarrierAndSuspendStable
public void closeBarrierAndSuspendStable()
-
openBarrierAndResumeStable
public void openBarrierAndResumeStable()
-
openBarrier
public void openBarrier()
-
resumeStable
public void resumeStable()
-
up
public java.lang.Object up(Event evt)
Description copied from class:Protocol
An event was received from the protocol below. Usually the current protocol will want to examine the event type and - depending on its type - perform some computation (e.g. removing headers from a MSG event type, or updating the internal membership list when receiving a VIEW_CHANGE event). Finally the event is either a) discarded, or b) an event is sent down the stack usingdown_prot.down()
or c) the event (or another event) is sent up the stack usingup_prot.up()
.
-
up
public java.lang.Object up(Message msg)
Description copied from class:Protocol
A single message was received. Protocols may examine the message and do something (e.g. add a header) with it before passing it up.
-
down
public java.lang.Object down(Event evt)
Description copied from class:Protocol
An event is to be sent down the stack. A protocol may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the protocol may need to add a header to it (or do nothing at all) before sending it down the stack usingdown_prot.down()
.
-
isDigestNeeded
protected boolean isDigestNeeded()
When FLUSH is used we do not need to pass digests between members see JGroups/doc/design/PartialStateTransfer.txt see JGroups/doc/design/FLUSH.txt- Returns:
- true if use of digests is required, false otherwise
-
punchHoleFor
protected void punchHoleFor(Address member)
-
closeHoleFor
protected void closeHoleFor(Address member)
-
determineCoordinator
protected Address determineCoordinator()
Return the first element of members which is not me. Otherwise return null.
-
handleViewChange
protected void handleViewChange(View v)
-
handleException
protected void handleException(java.lang.Throwable exception)
-
handle
public void handle(Address state_requester)
- Specified by:
handle
in interfaceProcessingQueue.Handler<Address>
-
handleStateReq
protected void handleStateReq(Address requester)
-
sendException
protected void sendException(Address requester, java.lang.Throwable exception)
-
-