org.unict.ing.pds.dhtdb.replica.p2p

Class NodeSessionBean

java.lang.Object

org.unict.ing.pds.dhtdb.utils.common.BaseNode

org.unict.ing.pds.dhtdb.replica.p2p.NodeSessionBean

All Implemented Interfaces:

NodeSessionBeanLocal, ChordNode, DHTNode

public class NodeSessionBean
extends BaseNode
implements NodeSessionBeanLocal

Responsible for the Chord primitives

Field Summary

Fields

Modifier and Type	Field and Description
private javax.ejb.SessionContext	context
private DBConnectionSingletonSessionBeanLocal	dBConnectionSingletonSessionBean CONFIG VARS END
private FingerSessionBeanLocal	fingerSessionBean
private static int	FIXFINGER_MULT
private static int	JOIN_MULT
private NodeReference	joinEntryPoint
private static int	PERIOD CONFIGS for the timers of periodically called methods
private RingSessionBeanLocal	ringSessionBean
private static int	STABILIZE_MULT
private Storage	storage

Fields inherited from class org.unict.ing.pds.dhtdb.utils.common.BaseNode

nodeRef

Constructor Summary

Constructors

Constructor and Description
NodeSessionBean()

Method Summary

Modifier and Type	Method and Description
void	bootstrap(NodeReference nodeRef) TODO
private boolean	checkPredecessor() Ping/Healthcheck of the predecessor
private void	create() Create new Chord Ring with only "myself"
List<GenericValue>	delete(Key key) Remove from the storage of the node executing this method
private void	fillFingertable() Fill the fingerTable
NodeReference	findSuccessor(Key key) findSuccessor primitive of chord protocol
private void	fixFingers() Fix fingerTable (recreates and Swap with LockWrite).
List<GenericValue>	get(Key key) Get a List of Values stored in the storage of the node executing this method with the given Key
private Boolean	getHasJoined()
List<GenericValue>	getLessThanAndRemove(Key key)
private BaseNode	getPredecessor()
NodeReference	getPredecessorNodeRef() Get the NodeReference of the Predecessor if it is set
private BaseNode	getReference(NodeReference nodeReference) get a NodeReference (to himSelf or as a RemoteNodeProxy for another peer)
private BaseNode	getSuccessor()
private void	init()
private boolean	isLocal(BaseNode obj) if the BaseNode given is himself returns true
private boolean	isLocal(NodeReference obj) if the NodeReference given is himself returns true
private boolean	isPredecessor(NodeReference obj) returns true if the NodeReference given is the predecessor
private Boolean	join(NodeReference entryPoint) Join a ring using an entry point
List<GenericValue>	lookup(Key key) Get a NodeReference to the successor of the given Key and make a Get in the associated peer
private void	moveKeys()
NodeReference	notify(NodeReference nodeRef) Notify primitive of the Chord Protocol
Boolean	put(GenericValue elem) Store a value in the storage of the node executing this method
Boolean	put(List<GenericValue> elems) Sore a list of GenericValue in the storage of the node executing this method
List<GenericValue>	remove(Key key) Remove a Key-Value from the successor associated with the given Key
private void	setHasJoined(Boolean hasJoined)
private void	setPredecessor(BaseNode predecessor)
private void	setSuccessor(BaseNode successor)
private void	stabilize() Stabilize the ring.
void	timeout(javax.ejb.Timer timer)
Boolean	update(Key key, List<GenericValue> elems) Update a Key-Value record from the successor associated with the given key
Boolean	write(Key key, GenericValue elem) Get a NodeReference to the successor of the given Key and make a put in the associated peer

Methods inherited from class org.unict.ing.pds.dhtdb.utils.common.BaseNode

getNodeReference

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.unict.ing.pds.dhtdb.replica.p2p.NodeSessionBeanLocal

getNodeReference

Field Detail

PERIOD

private static final int PERIOD

CONFIGS for the timers of periodically called methods

See Also:

Constant Field Values

JOIN_MULT

private static final int JOIN_MULT

See Also:

Constant Field Values

STABILIZE_MULT

private static final int STABILIZE_MULT

See Also:

Constant Field Values

FIXFINGER_MULT

private static final int FIXFINGER_MULT

See Also:

Constant Field Values

dBConnectionSingletonSessionBean

private DBConnectionSingletonSessionBeanLocal dBConnectionSingletonSessionBean

CONFIG VARS END

fingerSessionBean

private FingerSessionBeanLocal fingerSessionBean

ringSessionBean

private RingSessionBeanLocal ringSessionBean

storage

private Storage storage

joinEntryPoint

private NodeReference joinEntryPoint

context

private javax.ejb.SessionContext context

Constructor Detail

NodeSessionBean

public NodeSessionBean()

Method Detail

init

@PostConstruct
private void init()

timeout

public void timeout(javax.ejb.Timer timer)

create

private void create()

Create new Chord Ring with only "myself"

join

private Boolean join(NodeReference entryPoint)

Join a ring using an entry point

Parameters:

entryPoint - |

Returns:

|

notify

public NodeReference notify(NodeReference nodeRef)

Notify primitive of the Chord Protocol

Specified by:

notify in interface ChordNode

Parameters:

nodeRef - |

Returns:

|

stabilize

private void stabilize()

Stabilize the ring. Called periodically, asks the successor about its predecessor, verifies if our immediate successor is consistent, and tells the successor about us.

bootstrap

public void bootstrap(NodeReference nodeRef)

TODO

Specified by:

bootstrap in interface ChordNode

Parameters:

nodeRef - |

moveKeys

private void moveKeys()

getLessThanAndRemove

public List<GenericValue> getLessThanAndRemove(Key key)

Specified by:

getLessThanAndRemove in interface ChordNode

Parameters:

key - |

Returns:

|

fillFingertable

private void fillFingertable()

Fill the fingerTable

fixFingers

private void fixFingers()

Fix fingerTable (recreates and Swap with LockWrite).

get

public List<GenericValue> get(Key key)

Get a List of Values stored in the storage of the node executing this method with the given Key

Specified by:

get in interface DHTNode

Parameters:

key - |

Returns:

|

put

public Boolean put(GenericValue elem)

Store a value in the storage of the node executing this method

Specified by:

put in interface DHTNode

Parameters:

elem - |

Returns:

|

put

public Boolean put(List<GenericValue> elems)

Sore a list of GenericValue in the storage of the node executing this method

Specified by:

put in interface ChordNode

Parameters:

elems - |

Returns:

|

delete

public List<GenericValue> delete(Key key)

Remove from the storage of the node executing this method

Specified by:

delete in interface ChordNode

Parameters:

key - |

Returns:

|

lookup

public List<GenericValue> lookup(Key key)

Get a NodeReference to the successor of the given Key and make a Get in the associated peer

Specified by:

lookup in interface NodeSessionBeanLocal

Parameters:

key - |

Returns:

|

write

public Boolean write(Key key,
                     GenericValue elem)

Get a NodeReference to the successor of the given Key and make a put in the associated peer

Specified by:

write in interface NodeSessionBeanLocal

Parameters:

key - |

elem - |

Returns:

|

remove

public List<GenericValue> remove(Key key)

Remove a Key-Value from the successor associated with the given Key

Specified by:

remove in interface NodeSessionBeanLocal

Parameters:

key - |

Returns:

|

update

public Boolean update(Key key,
                      List<GenericValue> elems)

Update a Key-Value record from the successor associated with the given key

Specified by:

update in interface NodeSessionBeanLocal

Parameters:

key - |

elems - |

Returns:

|

findSuccessor

public NodeReference findSuccessor(Key key)

findSuccessor primitive of chord protocol

Specified by:

findSuccessor in interface ChordNode

Parameters:

key - |

Returns:

|

getReference

private BaseNode getReference(NodeReference nodeReference)

get a NodeReference (to himSelf or as a RemoteNodeProxy for another peer)

Parameters:

nodeReference - |

Returns:

|

isLocal

private boolean isLocal(BaseNode obj)

if the BaseNode given is himself returns true

Parameters:

obj - |

Returns:

|

isLocal

private boolean isLocal(NodeReference obj)

if the NodeReference given is himself returns true

Parameters:

obj - |

Returns:

|

isPredecessor

private boolean isPredecessor(NodeReference obj)

returns true if the NodeReference given is the predecessor

Parameters:

obj - |

Returns:

|

checkPredecessor

private boolean checkPredecessor()

Ping/Healthcheck of the predecessor

Returns:

|

getPredecessorNodeRef

public NodeReference getPredecessorNodeRef()

Get the NodeReference of the Predecessor if it is set

Specified by:

getPredecessorNodeRef in interface ChordNode

Returns:

|

getSuccessor

private BaseNode getSuccessor()

Returns:

| the successor

setSuccessor

private void setSuccessor(BaseNode successor)

Parameters:

successor - the successor to set |

getPredecessor

private BaseNode getPredecessor()

Returns:

| the predecessor

setPredecessor

private void setPredecessor(BaseNode predecessor)

Parameters:

predecessor - the predecessor to set |

getHasJoined

private Boolean getHasJoined()

Returns:

| the hasJoined

setHasJoined

private void setHasJoined(Boolean hasJoined)

Parameters:

hasJoined - the hasJoined to set |