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Class JavaGroups.JavaStack.Protocols.MACK

java.lang.Object
   |
   +----JavaGroups.JavaStack.Protocol
           |
           +----JavaGroups.JavaStack.Protocols.MACK

public class MACK
extends Protocol

Multicast ACKnowledgement protocol layer. For each message sent, we expect ACKs from all group members. When an ACK from a member has not been received for a certain time, the message will be resent to that member. If, after n retries, no ACK has been received, the member is suspected. If the view changes while waiting for ACKs, the list of members from which ACKs are expected is changed correspondingly.

Currently implemented without sliding window; all ACKs for a request have to be received before a new request can be sent, which is not very efficient ! TODO: implement sliding window, this allows multiple send requests to be processed at once (depending on the window size).

Use this protocol when

size of the group is relatively small
not too many messages are sent

The properties guaranteed by the protocol are

no message is lost
if a receiver does not respond, it will be excluded from the group
the messages from a sender to receiver are received in FIFO order

MACK()

Down(Event): An event is to be sent down the stack.
GetName()
SetProperties(Properties): Configures the protocol initially.
Up(Event): An event was received from the layer below.

MACK

 public MACK()

GetName

 public String GetName()

Overrides:: GetName in class Protocol

SetProperties

 public boolean SetProperties(Properties props)

Configures the protocol initially.

Overrides:: SetProperties in class Protocol

 public void Up(Event evt)

An event was received from the layer below.

Overrides:: Up in class Protocol

Down

 public void Down(Event evt)

An event is to be sent down the stack.

Overrides:: Down in class Protocol

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