org.gridbus.broker.persistence.db
Class DBWriter

java.lang.Object
  org.gridbus.broker.persistence.db.DBWriter

All Implemented Interfaces:

Writer

public final class DBWriter
extends java.lang.Object
implements Writer

Author:

krishna This class implements the Writer class to provide persistence, using a RDBMS. It uses JDBC, so that any database can be used with the broker. All the "save*" methods assume there is a valid open connection to the database, and the private field s "state" object is set. To set the state The connect method needs to be called to connect before saving anything. The methods which need transactions should explicitly use transactions on the connection used.

Constructor Summary

DBWriter()
Default constructor for this class, Assumes the following default values: Database driver: mySQL Database name: gridbusbroker Server: localhost.

DBWriter(java.lang.String driver, java.lang.String connectionString, java.lang.String username, java.lang.String password)
Constructor specifying the JDBC driver class name to use

Method Summary

boolean	connect() Sets up the database connection, if it is not already set up.
boolean	disconnect() Closes the database connection
void	save(GridbusFarmingEngine gfe) Saves the entire broker state to persistent storage.
void	saveBrokerInstance(GridbusFarmingEngine gfe) Saves the global broker properties and broker instance state to persistent storage.
void	saveDataFile(DataFile df, java.lang.Object brokerID) Saves a datafile to persistent storage.
void	saveDataFiles(java.util.Collection datafiles, java.lang.Object brokerID) Saves a collection of datafile to persistent storage.
void	saveDataHost(DataHost dh, java.lang.Object brokerID) Saves a datahost to persistent storage
void	saveDataHosts(java.util.Collection datahosts, java.lang.Object brokerID) Saves a collection of datahosts to persistent storage
void	saveEvent(GridbusFarmingEngine gfe, java.lang.Object eventID, java.lang.Object sourceID, java.lang.Object brokerID) Saves this event to the state table, which keeps track of event history
void	saveJob(Job j, java.lang.Object brokerID) Saves a job to persistent storage
void	saveJobs(java.util.Collection jobs, java.lang.Object brokerID) Saves a collection of jobs to persistent storage
void	saveServer(ComputeServer cs, java.lang.Object brokerID) Saves a compute server to persistent storage
void	saveServers(java.util.Collection servers, java.lang.Object brokerID) Saves a collection of computeServers to persistent storage

Methods inherited from class java.lang.Object

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

Constructor Detail

DBWriter

public DBWriter()
         throws java.lang.Exception

Default constructor for this class, Assumes the following default values: Database driver: mySQL Database name: gridbusbroker Server: localhost. Username: brokeruser, password: gridbus It is always better to use the constructor which takes the driver and connectionString parameters.

Throws:

java.lang.Exception

DBWriter

public DBWriter(java.lang.String driver,
                java.lang.String connectionString,
                java.lang.String username,
                java.lang.String password)
         throws java.lang.Exception

Constructor specifying the JDBC driver class name to use

Parameters:

driver -

connectionString -

username -

password -

Throws:

java.lang.Exception

Method Detail

saveDataHost

public void saveDataHost(DataHost dh,
                         java.lang.Object brokerID)
                  throws java.lang.Exception

Description copied from interface: Writer

Saves a datahost to persistent storage

Specified by:

saveDataHost in interface Writer

Parameters:

dh -

brokerID -

Throws:

java.lang.Exception

See Also:

Writer.saveDataHost(org.gridbus.broker.farming.common.data.DataHost, Object)

saveDataFile

public void saveDataFile(DataFile df,
                         java.lang.Object brokerID)
                  throws java.lang.Exception

Description copied from interface: Writer

Saves a datafile to persistent storage.

Specified by:

saveDataFile in interface Writer

Parameters:

df -

brokerID -

Throws:

java.lang.Exception

See Also:

Writer.saveDataFile(org.gridbus.broker.farming.common.data.DataFile, Object)

saveJob

public void saveJob(Job j,
                    java.lang.Object brokerID)
             throws java.lang.Exception

Description copied from interface: Writer

Saves a job to persistent storage

Specified by:

saveJob in interface Writer

Parameters:

j -

Throws:

java.lang.Exception

See Also:

Writer.saveJob(org.gridbus.broker.farming.common.Job, Object)

saveServer

public void saveServer(ComputeServer cs,
                       java.lang.Object brokerID)
                throws java.lang.Exception

Description copied from interface: Writer

Saves a compute server to persistent storage

Specified by:

saveServer in interface Writer

Parameters:

cs -

Throws:

java.lang.Exception

See Also:

Writer.saveServer(org.gridbus.broker.farming.common.ComputeServer, Object)

saveBrokerInstance

public void saveBrokerInstance(GridbusFarmingEngine gfe)
                        throws java.lang.Exception

Description copied from interface: Writer

Saves the global broker properties and broker instance state to persistent storage. This method just saves the broker instance itself, and not the objects contained in / linked with the broker. For saving the entire state, use the save(State) method.

Specified by:

saveBrokerInstance in interface Writer

Parameters:

gfe -

Throws:

java.lang.Exception

connect

public boolean connect()
                throws java.lang.Exception

Sets up the database connection, if it is not already set up. So, an existing connection is always re-used, if possible.

Specified by:

connect in interface Writer

Returns:

Throws:

java.lang.Exception

disconnect

public boolean disconnect()
                   throws java.lang.Exception

Closes the database connection

Specified by:

disconnect in interface Writer

Returns:

Throws:

java.lang.Exception

saveEvent

public void saveEvent(GridbusFarmingEngine gfe,
                      java.lang.Object eventID,
                      java.lang.Object sourceID,
                      java.lang.Object brokerID)
               throws java.lang.Exception

Saves this event to the state table, which keeps track of event history

Specified by:

saveEvent in interface Writer

Parameters:

gfe -

eventID -

sourceID -

brokerID -

Throws:

java.lang.Exception

save

public void save(GridbusFarmingEngine gfe)
          throws java.lang.Exception

Description copied from interface: Writer

Saves the entire broker state to persistent storage. All the save methods assume there is an open connecction to persistent storage, whether it is a database, or the file system or a network socket etc..

Specified by:

save in interface Writer

Parameters:

gfe -

Throws:

java.lang.Exception

saveDataHosts

public void saveDataHosts(java.util.Collection datahosts,
                          java.lang.Object brokerID)
                   throws java.lang.Exception

Description copied from interface: Writer

Saves a collection of datahosts to persistent storage

Specified by:

saveDataHosts in interface Writer

Throws:

java.lang.Exception

See Also:

org.gridbus.broker.persistence.Writer#saveDataHosts(java.util.Vector, Object)

saveDataFiles

public void saveDataFiles(java.util.Collection datafiles,
                          java.lang.Object brokerID)
                   throws java.lang.Exception

Description copied from interface: Writer

Saves a collection of datafile to persistent storage.

Specified by:

saveDataFiles in interface Writer

Throws:

java.lang.Exception

See Also:

org.gridbus.broker.persistence.Writer#saveDataFiles(java.util.Vector, Object)

saveJobs

public void saveJobs(java.util.Collection jobs,
                     java.lang.Object brokerID)
              throws java.lang.Exception

Description copied from interface: Writer

Saves a collection of jobs to persistent storage

Specified by:

saveJobs in interface Writer

Throws:

java.lang.Exception

See Also:

org.gridbus.broker.persistence.Writer#saveJobs(java.util.Vector, Object)

saveServers

public void saveServers(java.util.Collection servers,
                        java.lang.Object brokerID)
                 throws java.lang.Exception

Description copied from interface: Writer

Saves a collection of computeServers to persistent storage

Specified by:

saveServers in interface Writer

Throws:

java.lang.Exception

See Also:

org.gridbus.broker.persistence.Writer#saveServers(java.util.Vector, Object)