org.javagroups.protocols
Class MERGE
java.lang.Object
|
+--org.javagroups.stack.Protocol
|
+--org.javagroups.protocols.MERGE
- All Implemented Interfaces:
- java.lang.Runnable
- public class MERGE
- extends Protocol
- implements java.lang.Runnable
Simple and stupid MERGE protocol (does not take into account state transfer).
Periodically mcasts a HELLO message with its own address. When a HELLO message is
received from a member that has the same group (UDP discards all messages with a group
name different that our own), but is not currently in the group, a MERGE event is sent
up the stack. The protocol starts working upon receiving a View in which it is the coordinator.
- Author:
- Gianluca Collot, Jan 2001
Fields inherited from class org.javagroups.stack.Protocol |
down_handler, down_prot, down_queue, down_thread, observer, props, stack, up_handler, up_prot, up_queue, up_thread |
Constructor Summary |
MERGE()
|
Method Summary |
void |
down(Event evt)
An event is to be sent down the stack. |
java.lang.String |
getName()
|
void |
run()
If IP multicast: periodically mcast a HELLO message
If gossiping: periodically retrieve the membership. |
boolean |
setProperties(java.util.Properties props)
Configures the protocol initially. |
void |
up(Event evt)
An event was received from the layer below. |
Methods inherited from class org.javagroups.stack.Protocol |
getDownProtocol, getDownQueue, getProperties, getUpProtocol, getUpQueue, init, passDown, passUp, providedDownServices, providedUpServices, receiveDownEvent, receiveUpEvent, requiredDownServices, requiredUpServices, setDownProtocol, setObserver, setPropertiesInternal, setProtocolStack, setUpProtocol, startDownHandler, startUpHandler, stopInternal |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
MERGE
public MERGE()
getName
public java.lang.String getName()
- Overrides:
getName
in class Protocol
setProperties
public boolean setProperties(java.util.Properties props)
- Description copied from class:
Protocol
- Configures the protocol initially. A configuration string consists of name=value
items, separated by a ';' (semicolon), e.g.:
"loopback=false;unicast_inport=4444"
- Overrides:
setProperties
in class Protocol
up
public void up(Event evt)
- Description copied from class:
Protocol
- An event was received from the layer below. Usually the current layer 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
passDown()
or c) the event (or another event) is sent up
the stack using passUp()
.
- Overrides:
up
in class Protocol
down
public void down(Event evt)
- Description copied from class:
Protocol
- An event is to be sent down the stack. The layer 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 layer may need to add a header to it (or do nothing at all) before sending it down
the stack using
passDown()
. In case of a GET_ADDRESS event (which tries to
retrieve the stack's address from one of the bottom layers), the layer may need to send
a new response event back up the stack using passUp()
.
- Overrides:
down
in class Protocol
run
public void run()
- If IP multicast: periodically mcast a HELLO message
If gossiping: periodically retrieve the membership. Any members not part of our
own membership are merged (passing MERGE event up).
- Specified by:
run
in interface java.lang.Runnable
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