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

java.lang.Object
  javax.management.StandardMBean
      org.objectweb.cjdbc.controller.jmx.AbstractStandardMBean
          org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer
              org.objectweb.cjdbc.controller.loadbalancer.raidb0.RAIDb0

All Implemented Interfaces:

AbstractLoadBalancerMBean, javax.management.DynamicMBean, javax.management.NotificationBroadcaster, javax.management.NotificationEmitter, XmlComponent

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 , Jaco Swart , Jean-Bernard van Zuylen

Nested Class Summary

Nested classes inherited from class javax.management.StandardMBean

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

macroHandler, parsingGranularity, raidbLevel, totalOrderQueue, vdb

Fields inherited from class org.objectweb.cjdbc.controller.jmx.AbstractStandardMBean

Fields inherited from class javax.management.StandardMBean

Fields inherited from interface org.objectweb.cjdbc.common.xml.XmlComponent

DOCTYPE_CONTROLLER, DOCTYPE_DB, XML_VERSION

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, boolean writeEnabled) Enables a Backend that was previously disabled.
ControllerResultSet	execReadOnlyReadStoredProcedure(StoredProcedure proc, MetadataCache metadataCache) Call a read-only stored procedure that returns a ResultSet.
ControllerResultSet	execReadRequest(SelectRequest request, MetadataCache metadataCache) Performs a read request on the backend that has the needed tables to executes the request.
ControllerResultSet	execReadStoredProcedure(StoredProcedure proc, MetadataCache metadataCache) Call a stored procedure that returns a ResultSet.
protected ControllerResultSet	executeRequestOnBackend(SelectRequest request, DatabaseBackend backend, MetadataCache metadataCache) Execute a read request on the selected backend.
int	execWriteRequest(AbstractWriteRequest request) Performs a write request on the backend that has the needed tables to executes the request.
ControllerResultSet	execWriteRequestWithKeys(AbstractWriteRequest request, MetadataCache metadataCache) 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
int	getNumberOfEnabledBackends() Get the number of currently enabled backends. 0 means that no backend is available.
java.lang.String	getXmlImpl() Get information about the Request Load Balancer in xml
void	releaseSavepoint(TransactionMarkerMetaData tm, java.lang.String name) Release a savepoint from a transaction
void	rollback(TransactionMarkerMetaData tm) Rollbacks a transaction.
void	rollback(TransactionMarkerMetaData tm, java.lang.String savepointName) Rollback a transaction to a savepoint
void	setSavepoint(TransactionMarkerMetaData tm, java.lang.String name) Set a savepoint to a transaction.
void	setWeight(java.lang.String name, int w) Associate a weight to a backend identified by its logical name.

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

executeReadStoredProcedureOnBackend, executeSelectRequestOnBackend, executeUpdateRequestOnBackend, executeUpdateRequestOnBackendWithKeys, executeWriteStoredProcedureOnBackend, getAssociatedString, getConnectionAndBeginTransaction, getParsingGranularity, getRAIDbLevel, getXml, handleMacros, removeHeadFromAndNotifyTotalOrderQueue, setMacroHandler, setParsingGranularity, setRAIDbLevel, waitForTotalOrder

Methods inherited from class org.objectweb.cjdbc.controller.jmx.AbstractStandardMBean

addNotificationListener, getDescription, getDescription, getDescription, getDescription, getDescription, getDescription, getNotificationInfo, getParameterName, getParameterName, removeNotificationListener, removeNotificationListener, sendNotification

Methods inherited from class javax.management.StandardMBean

cacheMBeanInfo, getAttribute, getAttributes, getCachedMBeanInfo, getClassName, getConstructors, getDescription, getImpact, getImplementation, getImplementationClass, getMBeanInfo, getMBeanInterface, invoke, setAttribute, setAttributes, setImplementation

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.lang.Exception

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.lang.Exception - if an error occurs

Method Detail

execReadRequest

public ControllerResultSet execReadRequest(SelectRequest request,
                                           MetadataCache metadataCache)
                                    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

metadataCache - the metadataCache if any or null

Returns:

the corresponding java.sql.ResultSet

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execReadRequest(SelectRequest, MetadataCache)

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

execWriteRequestWithKeys

public ControllerResultSet execWriteRequestWithKeys(AbstractWriteRequest request,
                                                    MetadataCache metadataCache)
                                             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

metadataCache - MetadataCache (null if none)

Returns:

auto generated keys

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execWriteRequestWithKeys(AbstractWriteRequest, MetadataCache)

executeRequestOnBackend

protected ControllerResultSet executeRequestOnBackend(SelectRequest request,
                                                      DatabaseBackend backend,
                                                      MetadataCache metadataCache)
                                               throws java.sql.SQLException

Execute a read request on the selected backend.

Parameters:

request - the request to execute

backend - the backend that will execute the request

metadataCache - the metadataCache if any or null

Returns:

the ControllerResultSet

Throws:

java.sql.SQLException - if an error occurs

execReadOnlyReadStoredProcedure

public ControllerResultSet execReadOnlyReadStoredProcedure(StoredProcedure proc,
                                                           MetadataCache metadataCache)
                                                    throws java.sql.SQLException

Description copied from class: AbstractLoadBalancer

Call a read-only stored procedure that returns a ResultSet. The stored procedure will be executed by one node only.

Specified by:

execReadOnlyReadStoredProcedure in class AbstractLoadBalancer

Parameters:

proc - the stored procedure call

metadataCache - MetadataCache (null if none)

Returns:

a ControllerResultSet value

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execReadOnlyReadStoredProcedure(StoredProcedure, MetadataCache)

execReadStoredProcedure

public ControllerResultSet execReadStoredProcedure(StoredProcedure proc,
                                                   MetadataCache metadataCache)
                                            throws java.sql.SQLException

Description copied from class: AbstractLoadBalancer

Call a stored procedure that returns a ResultSet. This stored procedure can possibly perform writes and will therefore be executed by all nodes.

Specified by:

execReadStoredProcedure in class AbstractLoadBalancer

Parameters:

proc - the stored procedure call

metadataCache - MetadataCache (null if none)

Returns:

a ControllerResultSet value

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execReadStoredProcedure(StoredProcedure, MetadataCache)

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.common.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

rollback

public void rollback(TransactionMarkerMetaData tm,
                     java.lang.String savepointName)
              throws java.sql.SQLException

Rollback a transaction to a savepoint

Specified by:

rollback in class AbstractLoadBalancer

Parameters:

tm - The transaction marker metadata

savepointName - The name of the savepoint

Throws:

java.sql.SQLException - if an error occurs

releaseSavepoint

public void releaseSavepoint(TransactionMarkerMetaData tm,
                             java.lang.String name)
                      throws java.sql.SQLException

Release a savepoint from a transaction

Specified by:

releaseSavepoint in class AbstractLoadBalancer

Parameters:

tm - The transaction marker metadata

name - The name of the savepoint ro release

Throws:

java.sql.SQLException - if an error occurs

setSavepoint

public void setSavepoint(TransactionMarkerMetaData tm,
                         java.lang.String name)
                  throws java.sql.SQLException

Set a savepoint to a transaction.

Specified by:

setSavepoint in class AbstractLoadBalancer

Parameters:

tm - The transaction marker metadata

name - The name of the new savepoint

Throws:

java.sql.SQLException - if an error occurs

enableBackend

public void enableBackend(DatabaseBackend db,
                          boolean writeEnabled)
                   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

writeEnabled - True if the backend must be enabled for writes

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.

Specified by:

setWeight in interface AbstractLoadBalancerMBean

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)

getNumberOfEnabledBackends

public int getNumberOfEnabledBackends()

Description copied from class: AbstractLoadBalancer

Get the number of currently enabled backends. 0 means that no backend is available.

Specified by:

getNumberOfEnabledBackends in class AbstractLoadBalancer

Returns:

number of currently enabled backends

See Also:

AbstractLoadBalancer.getNumberOfEnabledBackends()

getInformation

public java.lang.String getInformation()

Get information about the Request load balancer

Specified by:

getInformation in interface AbstractLoadBalancerMBean

Specified by:

getInformation in class AbstractLoadBalancer

Returns:

String containing information

getXmlImpl

public java.lang.String getXmlImpl()

Description copied from class: AbstractLoadBalancer

Get information about the Request Load Balancer in xml

Specified by:

getXmlImpl in class AbstractLoadBalancer

Returns:

String containing information, xml formatted

See Also:

AbstractLoadBalancer.getXmlImpl()