org.apache.tephra.examples

Class BalanceBooks

java.lang.Object

org.apache.tephra.examples.BalanceBooks

All Implemented Interfaces:

Closeable, AutoCloseable

public class BalanceBooks
extends Object
implements Closeable

Simple example application that launches a number of concurrent clients, one per "account". Each client attempts to make withdrawals from other clients, and deposit the same amount to its own account in a single transaction. Since this means the client will be updating both its own row and the withdrawee's row, this will naturally lead to transaction conflicts. All clients will run for a specified number of iterations. When the processing is complete, the total sum of all rows should be zero, if transactional integrity was maintained.

You can run the BalanceBooks application with the following command:

     ./bin/tephra run org.apache.tephra.examples.BalanceBooks [num clients] [num iterations]
   

where [num clients] is the number of concurrent client threads to use, and [num iterations] is the number of "transfer" operations to perform per client thread.

Constructor Summary

Constructors

Constructor and Description
BalanceBooks(int totalClients, int iterations)
BalanceBooks(int totalClients, int iterations, org.apache.hadoop.conf.Configuration conf)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Frees up the underlying resources common to all clients.
protected void	createTableIfNotExists(org.apache.hadoop.conf.Configuration conf, byte[] tableName, byte[][] columnFamilies)
void	init() Sets up common resources required by all clients.
static void	main(String[] args)
void	run() Runs all clients and waits for them to complete.
boolean	verify() Validates the current state of the data stored at the end of the test.

Methods inherited from class java.lang.Object

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

Constructor Detail

BalanceBooks

public BalanceBooks(int totalClients,
            int iterations)

BalanceBooks

public BalanceBooks(int totalClients,
            int iterations,
            org.apache.hadoop.conf.Configuration conf)

Method Detail

init

public void init()
          throws IOException

Sets up common resources required by all clients.

Throws:

IOException

run

public void run()
         throws IOException,
                InterruptedException

Runs all clients and waits for them to complete.

Throws:

IOException

InterruptedException

verify

public boolean verify()

Validates the current state of the data stored at the end of the test. Each update by a client consists of two parts: a withdrawal of a random amount from a randomly select other account, and a corresponding to deposit to the client's own account. So, if all the updates were performed consistently (no partial updates or partial rollbacks), then the total sum of all balances at the end should be 0.

close

public void close()

Frees up the underlying resources common to all clients.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

createTableIfNotExists

protected void createTableIfNotExists(org.apache.hadoop.conf.Configuration conf,
                          byte[] tableName,
                          byte[][] columnFamilies)
                               throws IOException

Throws:

IOException

main

public static void main(String[] args)