Package org.jgroups.protocols

Class FD

  • @Deprecated(forRemoval=true)
public class FD
extends Protocol
    Deprecated, for removal: This API element is subject to removal in a future version.
    Use FD_ALL2 or FD_ALL3 instead
    Failure detection based on simple heartbeat protocol. Regularly polls members for liveness. Multicasts SUSPECT messages when a member is not reachable. The simple algorithms works as follows: the membership is known and ordered. Each HB protocol periodically sends an 'are-you-alive' message to its *neighbor*. A neighbor is the next in rank in the membership list, which is recomputed upon a view change. When a response hasn't been received for n milliseconds and m tries, the corresponding member is suspected (and eventually excluded if faulty).

    FD starts when it detects (in a view change notification) that there are at least 2 members in the group. It stops running when the membership drops below 2.

    When a message is received from the monitored neighbor member, it causes the pinger thread to 'skip' sending the next are-you-alive message. Thus, traffic is reduced.

    Author:
    Bela Ban

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      protected class  FD.Broadcaster
      Deprecated, for removal: This API element is subject to removal in a future version.
      Task that periodically broadcasts a list of suspected members to the group.
      protected class  FD.BroadcastTask
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      static class  FD.FdHeader
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected class  FD.Monitor
      Deprecated, for removal: This API element is subject to removal in a future version.
      Task which periodically checks of the last_ack from ping_dest exceeded timeout and - if yes - broadcasts a SUSPECT message

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected FD.Broadcaster bcast_task
      Deprecated, for removal: This API element is subject to removal in a future version.
      Transmits SUSPECT message until view change or UNSUSPECT is received
      protected long last_ack
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected Address local_addr
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected java.util.concurrent.locks.Lock lock
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected int max_tries
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected java.util.List<Address> members
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected java.util.concurrent.Future<?> monitor_future
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected int num_heartbeats
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected int num_suspect_events
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected java.util.concurrent.atomic.AtomicInteger num_tries
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected Address ping_dest
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected java.util.List<Address> pingable_mbrs
      Deprecated, for removal: This API element is subject to removal in a future version.
      Members from which we select ping_dest.
      protected BoundedList<java.lang.String> suspect_history
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected long timeout
      Deprecated, for removal: This API element is subject to removal in a future version.
       
      protected TimeScheduler timer
      Deprecated, for removal: This API element is subject to removal in a future version.
       

    • Constructor Summary

      Constructors 
      Constructor Description
      FD()
      Deprecated, for removal: This API element is subject to removal in a future version.
       

    • Field Detail

      • timeout

        protected long timeout
        Deprecated, for removal: This API element is subject to removal in a future version.

      • max_tries

        protected int max_tries
        Deprecated, for removal: This API element is subject to removal in a future version.

      • num_heartbeats

        protected int num_heartbeats
        Deprecated, for removal: This API element is subject to removal in a future version.

      • num_suspect_events

        protected int num_suspect_events
        Deprecated, for removal: This API element is subject to removal in a future version.

      • suspect_history

        protected final BoundedList<java.lang.String> suspect_history
        Deprecated, for removal: This API element is subject to removal in a future version.

      • local_addr

        protected Address local_addr
        Deprecated, for removal: This API element is subject to removal in a future version.

      • last_ack

        protected volatile long last_ack
        Deprecated, for removal: This API element is subject to removal in a future version.

      • num_tries

        protected final java.util.concurrent.atomic.AtomicInteger num_tries
        Deprecated, for removal: This API element is subject to removal in a future version.

      • lock

        protected final java.util.concurrent.locks.Lock lock
        Deprecated, for removal: This API element is subject to removal in a future version.

      • ping_dest

        protected volatile Address ping_dest
        Deprecated, for removal: This API element is subject to removal in a future version.

      • members

        protected final java.util.List<Address> members
        Deprecated, for removal: This API element is subject to removal in a future version.

      • pingable_mbrs

        protected final java.util.List<Address> pingable_mbrs
        Deprecated, for removal: This API element is subject to removal in a future version.
        Members from which we select ping_dest. Copy of members minus the suspected members

      • timer

        protected TimeScheduler timer
        Deprecated, for removal: This API element is subject to removal in a future version.

      • monitor_future

        protected java.util.concurrent.Future<?> monitor_future
        Deprecated, for removal: This API element is subject to removal in a future version.

      • bcast_task

        protected final FD.Broadcaster bcast_task
        Deprecated, for removal: This API element is subject to removal in a future version.
        Transmits SUSPECT message until view change or UNSUSPECT is received

    • Constructor Detail

      • FD

        public FD()
        Deprecated, for removal: This API element is subject to removal in a future version.

    • Method Detail

      • getLocalAddress

        public java.lang.String getLocalAddress()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getMembers

        public java.lang.String getMembers()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getPingableMembers

        public java.lang.String getPingableMembers()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getPingDest

        public java.lang.String getPingDest()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getNumberOfHeartbeatsSent

        public int getNumberOfHeartbeatsSent()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getNumSuspectEventsGenerated

        public int getNumSuspectEventsGenerated()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getTimeout

        public long getTimeout()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • setTimeout

        public FD setTimeout​(long timeout)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getMaxTries

        public int getMaxTries()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • setMaxTries

        public FD setMaxTries​(int max_tries)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • getCurrentNumTries

        public int getCurrentNumTries()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • msgCountsAsHeartbeat

        public boolean msgCountsAsHeartbeat()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • msgCountsAsHeartbeat

        public FD msgCountsAsHeartbeat​(boolean m)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • printSuspectHistory

        public java.lang.String printSuspectHistory()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • resetStats

        public void resetStats()
        Deprecated, for removal: This API element is subject to removal in a future version.
        Overrides:
        resetStats in class Protocol

      • start

        public void start()
           throws java.lang.Exception
        Deprecated, for removal: This API element is subject to removal in a future version.
        Description copied from class: Protocol
        This method is called on a JChannel.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 class Protocol
        Throws:
        java.lang.Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, so JChannel.connect(String) will throw an exception

      • stop

        public void stop()
        Deprecated, for removal: This API element is subject to removal in a future version.
        Description copied from class: Protocol
        This method is called on a JChannel.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
        Overrides:
        stop in class Protocol

      • getPingDest

        protected Address getPingDest​(java.util.List<Address> mbrs)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • stopFailureDetection

        public void stopFailureDetection()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • startFailureDetection

        public void startFailureDetection()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • startMonitor

        protected void startMonitor()
        Deprecated, for removal: This API element is subject to removal in a future version.
        Requires lock to held by caller

      • stopMonitor

        protected void stopMonitor()
        Deprecated, for removal: This API element is subject to removal in a future version.
        Requires lock to be held by caller

      • isMonitorRunning

        public boolean isMonitorRunning()
        Deprecated, for removal: This API element is subject to removal in a future version.

      • up

        public java.lang.Object up​(Message msg)
        Deprecated, for removal: This API element is subject to removal in a future version.
        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.
        Overrides:
        up in class Protocol

      • up

        public void up​(MessageBatch batch)
        Deprecated, for removal: This API element is subject to removal in a future version.
        Description copied from class: Protocol
        Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

        The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(Message)), and - if true - calls Protocol.up(org.jgroups.Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

        Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.getMatchingMessages(short,boolean)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

        Overrides:
        up in class Protocol
        Parameters:
        batch - The message batch

      • down

        public java.lang.Object down​(Event evt)
        Deprecated, for removal: This API element is subject to removal in a future version.
        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 using down_prot.down().
        Overrides:
        down in class Protocol

      • sendHeartbeatResponse

        protected void sendHeartbeatResponse​(Address dest)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • unsuspect

        protected void unsuspect​(Address mbr)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • updateTimestamp

        protected void updateTimestamp​(Address sender)
        Deprecated, for removal: This API element is subject to removal in a future version.

      • computePingDest

        protected void computePingDest​(Address remove)
        Deprecated, for removal: This API element is subject to removal in a future version.
        Computes pingable_mbrs (based on the current membership and the suspected members) and ping_dest
        Parameters:
        remove - The member to be removed from pingable_mbrs