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Class JavaGroups.JavaStack.Protocols.STABLE

java.lang.Object
   |
   +----JavaGroups.JavaStack.Protocol
           |
           +----JavaGroups.JavaStack.MessageProtocol
                   |
                   +----JavaGroups.JavaStack.RpcProtocol
                           |
                           +----JavaGroups.JavaStack.Protocols.STABLE

public class STABLE

extends RpcProtocol

implements Runnable

The only difference is that instead of using counters for an estimation of messages received from each member, we retrieve this actual information from the NAKACK layer (which must be present for the STABLE protocol to work).

STABLE()

GetName()

Gossip(ViewId, long, long[], boolean[], Object)

Contains the highest sequence numbers as seen by sender

HandleDownEvent(Event)

Callback.

HandleUpEvent(Event)

Callback.

RequiredUpServices()

List of events that are required to be answered by some layer above.

run()

SetProperties(Properties)

Configures the protocol initially.

Stability(ViewId, long, long[], Object)

Contains the highest message sequence numbers (for each member) that can safely be deleted (because they have been seen by all members).

 public STABLE()

 public String GetName()

Overrides:

GetName in class RpcProtocol

 public Vector RequiredUpServices()

List of events that are required to be answered by some layer above.

Overrides:

RequiredUpServices in class Protocol

 public boolean SetProperties(Properties props)

Configures the protocol initially.

Overrides:

SetProperties in class Protocol

 public void Gossip(ViewId view_id,
                    long round,
                    long highest_seqnos[],
                    boolean heard[],
                    Object sender)

Contains the highest sequence numbers as seen by sender

Parameters:

view_id - The view ID in which the gossip was sent. Must be the same as ours, otherwise it is discarded

round - The round in which the gossip was sent

highest_seqnos - A vector with the highest sequence numbers as seen bu sender

heard - The sender's heard_from array. This allows us to minimize the gossip msgs for a given round as a member does not have to receive gossip msgs from each member, but members pass gossips they've received from others on in their own gossips. E.g. when a member P (of group {P,Q,R}) receives a gossip from R, its own gossip to Q might be {R,P}. Q, who hasn't received a gossip from R, will not need to receive it anymore as it is already sent by P. This simple scheme reduces the number of gossip messages needed.

sender - The sender of the gossip message (obviously :-))

 public void Stability(ViewId view_id,
                       long round,
                       long stability_vector[],
                       Object sender)

Contains the highest message sequence numbers (for each member) that can safely be deleted (because they have been seen by all members).

 public boolean HandleUpEvent(Event evt)

Callback. Called by superclass when event may be handled.

Do not use PassUp in this method as the event is passed up by default by the superclass after this method returns !

Returns:

boolean Defaults to true. If false, event will not be passed up the stack.

Overrides:

HandleUpEvent in class RpcProtocol

 public boolean HandleDownEvent(Event evt)

Callback. Called by superclass when event may be handled.

Do not use PassDown in this method as the event is passed down by default by the superclass after this method returns !

Returns:

boolean Defaults to true. If false, event will not be passed down the stack.

Overrides:

HandleDownEvent in class RpcProtocol

 public void run()

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