Package com.bank.trading.data

Class LamportClock

java.lang.Object

com.bank.trading.data.LamportClock

All Implemented Interfaces:

Runnable

public class LamportClock
extends Object
implements Runnable

Lamport clock service to keep track of the logical time of the system. All events that take place on any component of the HFTS are streamed to the LCS which timestamps them with a long starting from 1. The LCS immediately writes it to an in memory log file and adds to queue which will be used by the UDP multicast and Replay services which run on this server as well as the webInterface. The LCS is responsible for sending the most recent log data to the BackupData This service is run as a cluster with one active leader, the others on standby in case of failure. Uses heartbeats to check if the leader is alive.

Constructor Summary

Constructors

Constructor	Description
LamportClock(File logfile, InetSocketAddress address, Map<String,InetSocketAddress> subscribers)	Constructor to initialize the Lamport clock service.

Method Summary

Modifier and Type	Method	Description
byte[]	getCurrentAlgExecutable()	Get the alg executable that the system is currently using.
byte[]	getCurrentControlsExecutable()	Get the controls executable that the system is currently using.
InetSocketAddress	getServiceAddress(String serviceName)	Used to get the address of a service.
void	removeSubscriber(InetSocketAddress subscriber)	remove subscriber from the Lamport clock service.
void	run()	This method is responsible for running the Lamport clock service.
void	updateSubscriber(String name, InetSocketAddress subscriber)	add or update a subscriber to the Lamport clock service.

Methods inherited from class java.lang.Object

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

Constructor Details

LamportClock

public LamportClock(File logfile,
 InetSocketAddress address,
 Map<String,InetSocketAddress> subscribers)

Constructor to initialize the Lamport clock service.

Parameters:

logfile - the file to write the log data.

address - the address of this service.

subscribers - the list of subscribers to this service and their names.

Method Details

run

public void run()

This method is responsible for running the Lamport clock service. This also starts the UDP multicast and Replay services.

Specified by:

run in interface Runnable

updateSubscriber

public void updateSubscriber(String name,
 InetSocketAddress subscriber)

add or update a subscriber to the Lamport clock service.

Parameters:

name - the name of the subscriber.

subscriber - the address of the subscriber to add.

removeSubscriber

public void removeSubscriber(InetSocketAddress subscriber)

remove subscriber from the Lamport clock service.

Parameters:

subscriber - the address of the subscriber to remove.

getServiceAddress

public InetSocketAddress getServiceAddress(String serviceName)

Used to get the address of a service.

Parameters:

serviceName -

Returns:

the address of the service.

getCurrentAlgExecutable

public byte[] getCurrentAlgExecutable()

Get the alg executable that the system is currently using.

Returns:

the alg executable.

getCurrentControlsExecutable

public byte[] getCurrentControlsExecutable()

Get the controls executable that the system is currently using.

Returns:

the controls executable.