org.javagroups.protocols
Class TCPPING
java.lang.Object
|
+--org.javagroups.stack.Protocol
|
+--org.javagroups.protocols.TCPPING
- public class TCPPING
- extends Protocol
The TCPPING protocol layer retrieves the initial membership (used by the GMS when started
by sending event FIND_INITIAL_MBRS down the stack). We do this by mcasting TCPPING
requests to an IP MCAST address (or, if gossiping is enabled, by contacting the router).
The responses should allow us to determine the coordinator whom we have to contact,
e.g. in case we want to join the group. When we are a server (after having received the
BECOME_SERVER event), we'll respond to TCPPING requests with a TCPPING response.
The
FIND_INITIAL_MBRS event will eventually be answered with a FIND_INITIAL_MBRS_OK event up
the stack.
- Author:
- Bela Ban
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 |
Method Summary |
void |
down(Event evt)
An event is to be sent down the stack. |
java.lang.String |
getName()
|
java.util.Vector |
providedUpServices()
List of events that are provided to layers above (they will be handled when sent down from
above). |
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, 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 |
TCPPING
public TCPPING()
getName
public java.lang.String getName()
- Overrides:
getName
in class Protocol
providedUpServices
public java.util.Vector providedUpServices()
- Description copied from class:
Protocol
- List of events that are provided to layers above (they will be handled when sent down from
above).
- Overrides:
providedUpServices
in class Protocol
- Following copied from class:
org.javagroups.stack.Protocol
- Returns:
- Vector (of Integers)
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
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