org.objectweb.cjdbc.controller.loadbalancer.raidb0
Class RAIDb0

java.lang.Object
  org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer
      org.objectweb.cjdbc.controller.loadbalancer.raidb0.RAIDb0

public class RAIDb0

extends AbstractLoadBalancer

RAIDb-0: database partitioning.

The requests are sent to the backend nodes hosting the tables needed to execute the request. If no backend has the needed tables to perform a request, it will fail.

Version:

1.0

Author:

Emmanuel Cecchet

Field Summary

private java.util.ArrayList	backendThreads
private ReadPrioritaryFIFOWriteLock	backendThreadsRWLock
private CreateTablePolicy	createTablePolicy
protected static Trace	logger

Fields inherited from class org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer

parsingGranularity, raidbLevel, vdb

Constructor Summary

RAIDb0(VirtualDatabase vdb, CreateTablePolicy createTablePolicy)
Creates a new RAIDb-0 request load balancer.

Method Summary

void	begin(TransactionMarkerMetaData tm) Begins a new transaction.
void	commit(TransactionMarkerMetaData tm) Commits a transaction.
void	disableBackend(DatabaseBackend db) Disables a backend that was previously enabled.
void	enableBackend(DatabaseBackend db) Enables a Backend that was previously disabled.
java.sql.ResultSet	execReadRequest(SelectRequest request) Performs a read request on the backend that has the needed tables to executes the request.
java.sql.ResultSet	execReadStoredProcedure(StoredProcedure proc) Call a stored procedure that returns a ResultSet.
int	execWriteRequest(AbstractWriteRequest request) Performs a write request on the backend that has the needed tables to executes the request.
java.sql.ResultSet	execWriteRequestWithKeys(AbstractWriteRequest request) Perform a write request and return a ResultSet containing the auto generated keys.
int	execWriteStoredProcedure(StoredProcedure proc) Call a stored procedure that performs an update.
java.lang.String	getInformation() Get information about the Request load balancer
java.lang.String	getXmlInformation() Get information about the Request Load Balancer in xml
void	rollback(TransactionMarkerMetaData tm) Rollbacks a transaction.
void	setWeight(java.lang.String name, int w) Associate a weight to a backend identified by its logical name.
private void	updateSchema(DatabaseBackend b, AbstractWriteRequest request) Update the backend schema if needed

Methods inherited from class org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer

getParsingGranularity, getRAIDbLevel, setParsingGranularity, setRAIDbLevel

Methods inherited from class java.lang.Object

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

Field Detail

backendThreads

private java.util.ArrayList backendThreads

backendThreadsRWLock

private ReadPrioritaryFIFOWriteLock backendThreadsRWLock

createTablePolicy

private CreateTablePolicy createTablePolicy

logger

protected static Trace logger

Constructor Detail

RAIDb0

public RAIDb0(VirtualDatabase vdb,
              CreateTablePolicy createTablePolicy)
       throws java.sql.SQLException

Creates a new RAIDb-0 request load balancer.

Parameters:

vdb - the virtual database this load balancer belongs to.

createTablePolicy - the policy defining how 'create table' statements should be handled

Throws:

java.sql.SQLException - if an error occurs

Method Detail

execReadRequest

public java.sql.ResultSet execReadRequest(SelectRequest request)
                                   throws java.sql.SQLException

Performs a read request on the backend that has the needed tables to executes the request.

Specified by:

execReadRequest in class AbstractLoadBalancer

Parameters:

request - an SelectRequest

Returns:

the corresponding java.sql.ResultSet

Throws:

java.sql.SQLException - if an error occurs

execWriteRequest

public int execWriteRequest(AbstractWriteRequest request)
                     throws java.sql.SQLException

Performs a write request on the backend that has the needed tables to executes the request.

Specified by:

execWriteRequest in class AbstractLoadBalancer

Parameters:

request - an AbstractWriteRequest

Returns:

number of rows affected by the request

Throws:

java.sql.SQLException - if an error occurs

updateSchema

private final void updateSchema(DatabaseBackend b,
                                AbstractWriteRequest request)

Update the backend schema if needed

execWriteRequestWithKeys

public java.sql.ResultSet execWriteRequestWithKeys(AbstractWriteRequest request)
                                            throws java.sql.SQLException

Description copied from class: AbstractLoadBalancer

Perform a write request and return a ResultSet containing the auto generated keys.

Specified by:

execWriteRequestWithKeys in class AbstractLoadBalancer

Parameters:

request - an AbstractWriteRequest

Returns:

auto generated keys

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execWriteRequestWithKeys(AbstractWriteRequest)

execReadStoredProcedure

public java.sql.ResultSet execReadStoredProcedure(StoredProcedure proc)
                                           throws java.sql.SQLException

Description copied from class: AbstractLoadBalancer

Call a stored procedure that returns a ResultSet.

Specified by:

execReadStoredProcedure in class AbstractLoadBalancer

Parameters:

proc - the stored procedure call

Returns:

a java.sql.ResultSet value

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execReadStoredProcedure(org.objectweb.cjdbc.sql.StoredProcedure)

execWriteStoredProcedure

public int execWriteStoredProcedure(StoredProcedure proc)
                             throws java.sql.SQLException

Description copied from class: AbstractLoadBalancer

Call a stored procedure that performs an update.

Specified by:

execWriteStoredProcedure in class AbstractLoadBalancer

Parameters:

proc - the stored procedure call

Returns:

number of rows affected

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execWriteStoredProcedure(org.objectweb.cjdbc.sql.StoredProcedure)

begin

public final void begin(TransactionMarkerMetaData tm)
                 throws java.sql.SQLException

Begins a new transaction.

Specified by:

begin in class AbstractLoadBalancer

Parameters:

tm - the transaction marker metadata

Throws:

java.sql.SQLException - if an error occurs

commit

public void commit(TransactionMarkerMetaData tm)
            throws java.sql.SQLException

Commits a transaction.

Specified by:

commit in class AbstractLoadBalancer

Parameters:

tm - the transaction marker metadata

Throws:

java.sql.SQLException - if an error occurs

rollback

public void rollback(TransactionMarkerMetaData tm)
              throws java.sql.SQLException

Rollbacks a transaction.

Specified by:

rollback in class AbstractLoadBalancer

Parameters:

tm - the transaction marker metadata

Throws:

java.sql.SQLException - if an error occurs

enableBackend

public void enableBackend(DatabaseBackend db)
                   throws java.sql.SQLException

Enables a Backend that was previously disabled.

Ask the corresponding connection manager to initialize the connections if needed.

No sanity checks are performed by this function.

Specified by:

enableBackend in class AbstractLoadBalancer

Parameters:

db - the database backend to enable

Throws:

java.sql.SQLException - if an error occurs

disableBackend

public void disableBackend(DatabaseBackend db)
                    throws java.sql.SQLException

Disables a backend that was previously enabled.

Ask the corresponding connection manager to finalize the connections if needed.

No sanity checks are performed by this function.

Specified by:

disableBackend in class AbstractLoadBalancer

Parameters:

db - the database backend to disable

Throws:

java.sql.SQLException - if an error occurs

setWeight

public void setWeight(java.lang.String name,
                      int w)
               throws java.sql.SQLException

Description copied from class: AbstractLoadBalancer

Associate a weight to a backend identified by its logical name.

Overrides:

setWeight in class AbstractLoadBalancer

Parameters:

name - the backend name

w - the weight

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.setWeight(String, int)

getInformation

public java.lang.String getInformation()

Get information about the Request load balancer

Specified by:

getInformation in class AbstractLoadBalancer

Returns:

String containing information

getXmlInformation

public java.lang.String getXmlInformation()

Description copied from class: AbstractLoadBalancer

Get information about the Request Load Balancer in xml

Specified by:

getXmlInformation in class AbstractLoadBalancer

Returns:

String containing information, xml formatted

See Also:

AbstractLoadBalancer.getXmlInformation()