org.jgroups.protocols

Class MERGE2

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.MERGE2

Deprecated.

Use MERGE3 instead, as it causes less traffic, especially for large clusters

@Deprecated
public class MERGE2
extends Protocol

Protocol to discover subgroups; e.g., existing due to a network partition (that healed). Example: group {p,q,r,s,t,u,v,w} is split into 3 subgroups {p,q}, {r,s,t,u} and {v,w}. This protocol will eventually send a MERGE event with the coordinators of each subgroup up the stack: {p,r,v}. Note that - depending on the time of subgroup discovery - there could also be 2 MERGE events, which first join 2 of the subgroups, and then the resulting group to the last subgroup. The real work of merging the subgroups into one larger group is done somewhere above this protocol (typically in the GMS protocol).

This protocol works as follows:

• If coordinator: periodically multicast a discovery message. Everyone (or (if configured) only the coords) reply with their current view. Based on the received views:
• If there is more than 1 coordinator:
  1. Get all coordinators
  2. Create a MERGE event with the list of coordinators as argument
  3. Send the event up the stack

Provides: sends MERGE event with list of coordinators up the stack

Author:

Bela Ban, Oct 16 2001

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	MERGE2.FindSubgroupsTask Deprecated. Task periodically executing (if role is coordinator).
protected static class	MERGE2.MergeHeader Deprecated.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	cluster_name Deprecated.
protected Address	current_coord Deprecated.
protected CondVar	discovery_cond Deprecated.
protected java.util.concurrent.locks.Lock	discovery_lock Deprecated.
protected long	discovery_timeout Deprecated.
protected boolean	fetching_done Deprecated.
protected boolean	force_sending_discovery_rsps Deprecated.
protected int	inconsistent_view_threshold Deprecated.
protected boolean	is_coord Deprecated.
protected Address	local_addr Deprecated.
protected long	max_interval Deprecated.
protected java.util.Set<Address>	members Deprecated.
protected java.util.Set<Address>	merge_candidates Deprecated.
protected boolean	merge_fast Deprecated.
protected long	merge_fast_delay Deprecated.
protected long	min_interval Deprecated.
protected int	num_inconsistent_views Deprecated.
protected int	num_merge_events Deprecated.
protected MERGE2.FindSubgroupsTask	task Deprecated.
protected TimeScheduler	timer Deprecated.
protected boolean	transport_supports_multicasting Deprecated.
protected View	view Deprecated.
protected java.util.Map<Address,View>	views Deprecated.

Fields inherited from class org.jgroups.stack.Protocol

after_creation_hook, down_prot, ergonomics, id, log, name, stack, stats, up_prot

Constructor Summary

Constructors

Constructor and Description
MERGE2() Deprecated.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	down(Event evt) Deprecated. An event is to be sent down the stack.
java.lang.String	fetchAllViews() Deprecated.
java.lang.String	getCurrentCoord() Deprecated.
long	getMaxInterval() Deprecated.
long	getMinInterval() Deprecated.
protected void	handle(MERGE2.MergeHeader hdr, Address sender) Deprecated.
void	init() Deprecated. Called after instance has been created (null constructor) and before protocol is started.
protected boolean	isMergeRunning() Deprecated.
boolean	isMergeTaskRunning() Deprecated.
protected void	mergeFast(Address dest, Address sender) Deprecated.
void	sendMergeSolicitation() Deprecated. Discovers members and detects whether we have multiple coordinator.
void	setMaxInterval(long l) Deprecated.
void	setMinInterval(long i) Deprecated.
void	startMergeTask() Deprecated.
void	stop() Deprecated. This method is called on a Channel.disconnect().
void	stopMergeTask() Deprecated.
java.lang.Object	up(Event evt) Deprecated. An event was received from the layer below.
void	up(MessageBatch batch) Deprecated. Sends up a multiple messages in a MessageBatch.

Methods inherited from class org.jgroups.stack.Protocol

accept, afterCreationHook, destroy, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, resetStats, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, start, statsEnabled

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

min_interval

protected long min_interval

Deprecated.

max_interval

protected long max_interval

Deprecated.

inconsistent_view_threshold

protected int inconsistent_view_threshold

Deprecated.

merge_fast

protected boolean merge_fast

Deprecated.

merge_fast_delay

protected long merge_fast_delay

Deprecated.

force_sending_discovery_rsps

protected boolean force_sending_discovery_rsps

Deprecated.

discovery_timeout

protected long discovery_timeout

Deprecated.

local_addr

protected Address local_addr

Deprecated.

view

protected volatile View view

Deprecated.

members

protected final java.util.Set<Address> members

Deprecated.

merge_candidates

protected final java.util.Set<Address> merge_candidates

Deprecated.

task

protected final MERGE2.FindSubgroupsTask task

Deprecated.

is_coord

protected volatile boolean is_coord

Deprecated.

current_coord

protected volatile Address current_coord

Deprecated.

timer

protected TimeScheduler timer

Deprecated.

num_inconsistent_views

protected int num_inconsistent_views

Deprecated.

num_merge_events

protected int num_merge_events

Deprecated.

views

protected final java.util.Map<Address,View> views

Deprecated.

discovery_lock

protected final java.util.concurrent.locks.Lock discovery_lock

Deprecated.

discovery_cond

protected final CondVar discovery_cond

Deprecated.

fetching_done

protected volatile boolean fetching_done

Deprecated.

transport_supports_multicasting

protected boolean transport_supports_multicasting

Deprecated.

cluster_name

protected java.lang.String cluster_name

Deprecated.

Constructor Detail

MERGE2

public MERGE2()

Deprecated.

Method Detail

isMergeTaskRunning

public boolean isMergeTaskRunning()

Deprecated.

init

public void init()
          throws java.lang.Exception

Deprecated.

Description copied from class: Protocol

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.

Overrides:

init in class Protocol

Throws:

java.lang.Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor will throw an exception

getMinInterval

public long getMinInterval()

Deprecated.

setMinInterval

public void setMinInterval(long i)

Deprecated.

getMaxInterval

public long getMaxInterval()

Deprecated.

setMaxInterval

public void setMaxInterval(long l)

Deprecated.

isMergeRunning

protected boolean isMergeRunning()

Deprecated.

sendMergeSolicitation

public void sendMergeSolicitation()

Deprecated.

Discovers members and detects whether we have multiple coordinator. If so, kicks off a merge

getCurrentCoord

public java.lang.String getCurrentCoord()

Deprecated.

startMergeTask

public void startMergeTask()

Deprecated.

stopMergeTask

public void stopMergeTask()

Deprecated.

fetchAllViews

public java.lang.String fetchAllViews()

Deprecated.

stop

public void stop()

Deprecated.

Description copied from class: Protocol

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

Overrides:

stop in class Protocol

down

public java.lang.Object down(Event evt)

Deprecated.

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 down_prot.down(). 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 up_prot.up().

Overrides:

down in class Protocol

up

public java.lang.Object up(Event evt)

Deprecated.

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 down_prot.down() or c) the event (or another event) is sent up the stack using up_prot.up().

Overrides:

up in class Protocol

up

public void up(MessageBatch batch)

Deprecated.

Description copied from class: Protocol

Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(org.jgroups.Message)), and - if true - calls Protocol.up(org.jgroups.Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.getMatchingMessages(short,boolean)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

Overrides:

up in class Protocol

Parameters:

batch - The message batch

mergeFast

protected void mergeFast(Address dest,
                         Address sender)

Deprecated.

handle

protected void handle(MERGE2.MergeHeader hdr,
                      Address sender)

Deprecated.