org.jgroups.protocols
Class FD_SIMPLE
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.
down_handler , down_prot , down_queue , down_thread , down_thread_prio , log , observer , props , stack , up_handler , up_prot , up_queue , up_thread , up_thread_prio |
void | down(Event evt) - An event is to be sent down the stack.
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String | getName()
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void | init() - Called after instance has been created (null constructor) and before protocol is started.
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boolean | setProperties(Properties props) - Configures the protocol initially.
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void | stop() - This method is called on a
Channel.disconnect() .
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void | up(Event evt) - An event was received from the layer below.
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destroy , down , getDownProtocol , getDownQueue , getName , getProperties , getUpProtocol , getUpQueue , handleSpecialDownEvent , init , passDown , passUp , providedDownServices , providedUpServices , receiveDownEvent , receiveUpEvent , requiredDownServices , requiredUpServices , setDownProtocol , setObserver , setProperties , setPropertiesInternal , setProtocolStack , setUpProtocol , start , startDownHandler , startUpHandler , stop , stopInternal , up |
down
public void down(Event evt)
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()
.
- down in interface Protocol
init
public void init()
throws Exception
Called after instance has been created (null constructor) and before protocol is started.
Properties are already set. Other protocols are not yet connected and events cannot yet be sent.
- init in interface Protocol
setProperties
public boolean setProperties(Properties props)
Configures the protocol initially. A configuration string consists of name=value
items, separated by a ';' (semicolon), e.g.:
"loopback=false;unicast_inport=4444"
- setProperties in interface Protocol
stop
public void stop()
This method is called on a
Channel.disconnect()
. Stops work (e.g. by closing multicast socket).
Will be called
from top to bottom. This means that at the time of the method invocation the
neighbor protocol below is still working. This method will replace the
STOP,
STOP_OK,
CLEANUP and
CLEANUP_OK events. The ProtocolStack guarantees that
when this method is called all messages in the down queue will have been flushed
- stop in interface Protocol
up
public void up(Event evt)
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()
.
- up in interface Protocol
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