Class VERIFY_SUSPECT

  • All Implemented Interfaces:
    java.lang.Runnable

    public class VERIFY_SUSPECT
    extends Protocol
    implements java.lang.Runnable
    Catches SUSPECT events traveling up the stack. Verifies that the suspected member is really dead. If yes, passes SUSPECT event up the stack, otherwise discards it. Has to be placed somewhere above the FD layer and below the GMS layer (receiver of the SUSPECT event). Note that SUSPECT events may be reordered by this protocol.
    Author:
    Bela Ban
    • Field Detail

      • timeout

        protected long timeout
      • num_msgs

        protected int num_msgs
      • use_icmp

        protected boolean use_icmp
      • use_mcast_rsps

        protected boolean use_mcast_rsps
      • bind_addr

        protected java.net.InetAddress bind_addr
      • intf

        protected java.net.NetworkInterface intf
        network interface to be used to send the ICMP packets
      • local_addr

        protected Address local_addr
      • timer

        protected java.lang.Thread timer
      • running

        protected volatile boolean running
    • Constructor Detail

      • VERIFY_SUSPECT

        public VERIFY_SUSPECT()
    • Method Detail

      • getSuspects

        public java.lang.String getSuspects()
      • getTimeout

        public long getTimeout()
      • 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 using down_prot.down().
        Overrides:
        down in class Protocol
      • 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 using down_prot.down() or c) the event (or another event) is sent up the stack using up_prot.up().
        Overrides:
        up in class Protocol
      • 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.
        Overrides:
        up in class Protocol
      • adjustSuspectedMembers

        protected void adjustSuspectedMembers​(java.util.List<Address> new_mbrship)
        Removes all elements from suspects that are not in the new membership
      • run

        public void run()
        Started when a suspected member is added to suspects. Iterates over the queue as long as there are suspects in it and removes a suspect when the timeout for it has elapsed. Sends up a SUSPECT event for every removed suspect. When a suspected member is un-suspected, the member is removed from the queue.
        Specified by:
        run in interface java.lang.Runnable
      • verifySuspect

        protected void verifySuspect​(java.util.Collection<Address> mbrs)
        Sends ARE_YOU_DEAD message to suspected_mbr, wait for return or timeout
      • verifySuspectWithICMP

        protected void verifySuspectWithICMP​(Address suspected_mbr)
      • addSuspects

        protected boolean addSuspects​(java.util.Collection<Address> list)
        Adds suspected members to the suspect list. Returns true if a member is not present and the timer is not running.
        Parameters:
        list - The list of suspected members
        Returns:
        true if the timer needs to be started, or false otherwise
      • removeSuspect

        protected boolean removeSuspect​(Address suspect)
      • clearSuspects

        protected void clearSuspects()
      • unsuspect

        public void unsuspect​(Address mbr)
      • startTimer

        protected void startTimer()
      • stopTimer

        protected void stopTimer()
      • start

        public void start()
                   throws java.lang.Exception
        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()
        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