FountainMasterNode Class Reference
[Fountain master and slave nodes]

The FountainMasterNode class extends the FountainNode class by adding or overloading methods to recover from tree failures and handle requests from the Fountain server. More...

#include <FountainMasterNode.h>

Inheritance diagram for FountainMasterNode:

List of all members.

Public Member Functions
void	checkConnections ()
	Handles incoming connection requests and messages on existing connections.
Private Types
typedef Loki::SmartPtr< TreeTopology >	TreeTopologyPtr
	Shorthand for a TreeTopology pointer wrapped inside a SmartPtr object.
Private Member Functions
void	handleJoinAsServer (ConstParseMsgPtr request, FountainWireProtPtr serverCon)
	handles a join request from the Fountain server
void	handleJoin (ConstParseMsgPtr request, FountainWireProtPtr requestConnection)
int	handleLostChild (const NodeID &childID)
	Handles a lost child of the master Fountain node.
void	checkTree ()
	Checks the status of the tree topology.
void	joinMasterNode ()
	Overloads FountainNode::joinMasterNode() method so this does nothing.
void	handleLostParent (const char *message)
	Overloads FountainNode::handleLostParent() method so this does nothing.
void	rebuildTree (unsigned int degree=0)
	If the Tree Topology could not be recovered from a node failure, this method will rebuild the tree from scratch.
NodeResponsePtr	processRequest (FountainMessage::MessageAction action, ConstParseMsgPtr request, time_t timeout)
	Handles master Fountain node specific requests.
	FountainMasterNode (const NodeID &myID)
	Default constructor, private since we're using a singleton design pattern.
	FountainMasterNode (const FountainMasterNode &rhs)
	Private copy constructor since we're using a singleton design pattern.
FountainMasterNode &	operator= (const FountainMasterNode &rhs)
	Private assignment operator since we're using a singleton design pattern.
	~FountainMasterNode ()
	Private destructor since we're using a singleton design pattern.
Private Attributes
TreeTopologyPtr	treeTopologyPtr_
std::string	myActor_
Friends
class	FountainNodeCreator

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Detailed Description

The FountainMasterNode class extends the FountainNode class by adding or overloading methods to recover from tree failures and handle requests from the Fountain server.

This is a singleton class since it really does not make sense for any application to maintain multiple FountainMasterNode objects. This object is instantiated by the masterNode.cpp driver code on and it typically will run on the head node of a cluster. It extends the FountainNode class by adding methods to handle lost parent and child nodes, which are reported by the other nodes in the Fountain tree topology.

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Member Function Documentation

void FountainMasterNode::checkConnections (   )  [virtual]

Handles incoming connection requests and messages on existing connections. Todo: Devise a method to effectively make each of these handling functions throw an exception. sjm 2-9-2006 Reimplemented from FountainNode.

void FountainMasterNode::checkTree (   )  [private]

Checks the status of the tree topology. This method checks the status of the tree topology and attempts to recover or rebuilt it if any nodes in the tree are lost Exceptions: FountainException  if the tree topology could not be recoveries and it had to be rebuilt

void FountainMasterNode::handleJoin (  ConstParseMsgPtr  request, FountainWireProtPtr  requestConnection )  [private]

Handles join requests from an incoming connection. Parameters: request  the request message from the node attempting to join us requestConnection  the connection that sent the join request Precondition: valid request and requestConnection Postcondition: Accept the request as a node in the tree topology The master Fountain node join algorithm matches the following requirements in the join request message before accepting the slave Fountain node into the tree topology: Their Version data element matches ours They have a valid actor attribute If restrictActors is true, we need to only accept actors equal to us If restrictHostnames is true, we lookup their hostname to make sure it is valid and other Fountain nodes can connect to them Reimplemented from FountainNode.

void FountainMasterNode::handleJoinAsServer (  ConstParseMsgPtr  request, FountainWireProtPtr  serverCon )  [private]

handles a join request from the Fountain server A Fountain server process will attempt to join us, this function will either accept the request to join, or reject it if we already have a Fountain server connection. Exceptions: FountainException  if there is an error when parsing the request

int FountainMasterNode::handleLostChild (  const NodeID &  childID  )  [private, virtual]

Handles a lost child of the master Fountain node. Handles a lost child Fountain node. Parameters: childID  The NodeID of the lost child Fountain node Return values: int  SUCCESS if the lost child node should be removed from the children vector, FAILURE if the lost child node should NOT be removed from the children vector Exceptions: FountainException  if the lost child node could not be reported to the master node Reimplemented from FountainNode.

void FountainMasterNode::handleLostParent (  const char *  message  )  [inline, private, virtual]

Overloads FountainNode::handleLostParent() method so this does nothing. Handles a lost parent Fountain node. Parameters: message  A c-string to add as the Message element in the request to the master Fountain node Exceptions: FountainException  if handling the lost parent Fountain node was not successful Reimplemented from FountainNode.

void FountainMasterNode::joinMasterNode (   )  [inline, private, virtual]

Overloads FountainNode::joinMasterNode() method so this does nothing. Joins the master Fountain Node using the hostname and port specified in the FountainNode constructor. Exceptions: FountainException  if we could not join the master Fountain node Reimplemented from FountainNode.

NodeResponsePtr FountainMasterNode::processRequest (  FountainMessage::MessageAction  action, ConstParseMsgPtr  request, time_t  timeout )  [private, virtual]

Handles master Fountain node specific requests. Process and respond to a request message from our parent. Parameters: [in]  action  The message action [in]  request  The request message from our parent [in]  timeout  The number of seconds to wait for a response from each child node Return values: NodeResponsePtr  The response message to send back to our parent Precondition: request != NULL Reimplemented from FountainNode.

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Member Data Documentation

std::string FountainMasterNode::myActor_ [private]

The userid that launched us

TreeTopologyPtr FountainMasterNode::treeTopologyPtr_ [private]

Pointer to our tree object

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The documentation for this class was generated from the following files:

• /afs/scl.ameslab.gov/user/samm/fountain/source/nodes/FountainMasterNode.h
• /afs/scl.ameslab.gov/user/samm/fountain/source/nodes/FountainMasterNode.cpp

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