org.javagroups.protocols
Class FD_SIMPLE
java.lang.Object
|
+--org.javagroups.stack.Protocol
|
+--org.javagroups.protocols.FD_SIMPLE
- public class FD_SIMPLE
- extends Protocol
Simple failure detection protocol. Periodically sends a are-you-alive message to a randomly chosen member
(excluding itself) and waits for a response. If a response has not been received within timeout msecs, a counter
associated with that member will be incremented. If the counter exceeds max_missed_hbs, that member will be
suspected. When a message or a heartbeat are received, the counter is reset to 0.
- Version:
- $Revision: 1.3 $
- Author:
- Bela Ban Aug 2002
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()
|
void |
init()
Called after instance has been created (null constructor) and before protocol is started |
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, 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 |
FD_SIMPLE
public FD_SIMPLE()
getName
public java.lang.String getName()
- Overrides:
getName
in class Protocol
init
public void init()
throws java.lang.Exception
- Description copied from class:
Protocol
- Called after instance has been created (null constructor) and before protocol is started
- Overrides:
init
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
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