org.objectweb.cjdbc.controller.loadbalancer.raidb2
Class RAIDb2

java.lang.Object
  javax.management.StandardMBean
      org.objectweb.cjdbc.controller.jmx.AbstractStandardMBean
          org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer
              org.objectweb.cjdbc.controller.loadbalancer.raidb2.RAIDb2

All Implemented Interfaces:

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

Direct Known Subclasses:

RAIDb2_LPRF, RAIDb2_RR, RAIDb2_WRR, RAIDb2ec

public abstract class RAIDb2

extends AbstractLoadBalancer

RAIDb-2 load balancer.

This class is an abstract call because the read requests coming from the Request Manager are NOT treated here but in the subclasses. Transaction management and write requests are broadcasted to all backends owning the written table.

Version:

1.0

Author:

Emmanuel Cecchet , Jean-Bernard van Zuylen

Nested Class Summary

Nested classes inherited from class javax.management.StandardMBean

Field Summary

protected java.util.ArrayList	backendBlockingThreads
protected ReadPrioritaryFIFOWriteLock	backendBlockingThreadsRWLock
protected java.util.ArrayList	backendNonBlockingThreads
protected ReadPrioritaryFIFOWriteLock	backendNonBlockingThreadsRWLock
protected CreateTablePolicy	createTablePolicy
protected static Trace	logger
protected WaitForCompletionPolicy	waitForCompletionPolicy

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

RAIDb2(VirtualDatabase vdb, WaitForCompletionPolicy waitForCompletionPolicy, CreateTablePolicy createTablePolicy)
Creates a new RAIDb-1 Round Robin request load balancer.

Method Summary

void	begin(TransactionMarkerMetaData tm) Begins a new transaction.
private AbstractTask	callStoredProcedure(StoredProcedure proc, boolean isRead, MetadataCache metadataCache) Post the stored procedure call in the threads task list.
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.
abstract ControllerResultSet	execReadRequest(SelectRequest request, MetadataCache metadataCache) Implementation specific load balanced read execution.
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.
protected ControllerResultSet	executeStoredProcedureOnBackend(StoredProcedure proc, DatabaseBackend backend, MetadataCache metadataCache) Execute a stored procedure on the selected backend.
int	execWriteRequest(AbstractWriteRequest request) Performs a write request.
private AbstractTask	execWriteRequest(AbstractWriteRequest request, boolean useKeys, MetadataCache metadataCache) Common code for execWriteRequest(AbstractWriteRequest) and execWriteRequestWithKeys(AbstractWriteRequest).
ControllerResultSet	execWriteRequestWithKeys(AbstractWriteRequest request, MetadataCache metadataCache) Perform a write request and return the auto generated keys.
int	execWriteStoredProcedure(StoredProcedure proc) Call a stored procedure that performs an update.
private int	getNbToWait(int nbOfThreads) Returns the number of nodes to wait for according to the defined waitForCompletion policy.
int	getNumberOfEnabledBackends() Get the number of currently enabled backends. 0 means that no backend is available.
abstract java.lang.String	getRaidb2Xml() return xml formatted information about this raidb2 load balancer
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.
private void	waitForAllWritesToBePostedOnBackendBlockingThreads() Wait for all writes to be posted on BackendBlockingThreads by simply acquiring the RW lock in write and releasing it.
protected void	waitForAllWritesToComplete(DatabaseBackend backend) Waits for all writes in the blocking thread queue of the given backend to complete.
protected void	waitForAllWritesToComplete(DatabaseBackend backend, long transactionId) Waits for all writes of the given transaction in the blocking thread queue of the given backend to complete before being able to complete the transaction.
protected void	waitForAllWritesToComplete(long transactionId) Waits for all writes of the given transaction in the blocking thread queue to complete before being able to complete the transaction.

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

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

backendBlockingThreads

protected java.util.ArrayList backendBlockingThreads

backendNonBlockingThreads

protected java.util.ArrayList backendNonBlockingThreads

backendBlockingThreadsRWLock

protected ReadPrioritaryFIFOWriteLock backendBlockingThreadsRWLock

backendNonBlockingThreadsRWLock

protected ReadPrioritaryFIFOWriteLock backendNonBlockingThreadsRWLock

waitForCompletionPolicy

protected WaitForCompletionPolicy waitForCompletionPolicy

createTablePolicy

protected CreateTablePolicy createTablePolicy

logger

protected static Trace logger

Constructor Detail

RAIDb2

public RAIDb2(VirtualDatabase vdb,
              WaitForCompletionPolicy waitForCompletionPolicy,
              CreateTablePolicy createTablePolicy)
       throws java.lang.Exception

Creates a new RAIDb-1 Round Robin request load balancer. A new backend worker thread is created for each backend.

Parameters:

vdb - the virtual database this load balancer belongs to.

waitForCompletionPolicy - how many backends must complete before returning the result ?

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

Throws:

java.lang.Exception - if an error occurs

Method Detail

getNbToWait

private int getNbToWait(int nbOfThreads)

Returns the number of nodes to wait for according to the defined waitForCompletion policy.

Parameters:

nbOfThreads - total number of threads

Returns:

int number of threads to wait for

execWriteRequest

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

Performs a write request. This request is broadcasted to all nodes that owns the table to be written.

Specified by:

execWriteRequest in class AbstractLoadBalancer

Parameters:

request - an AbstractWriteRequest

Returns:

number of rows affected by the request

Throws:

AllBackendsFailedException - if all backends failed to execute the request

java.sql.SQLException - if an error occurs

execWriteRequestWithKeys

public ControllerResultSet execWriteRequestWithKeys(AbstractWriteRequest request,
                                                    MetadataCache metadataCache)
                                             throws AllBackendsFailedException,
                                                    java.sql.SQLException

Perform a write request and return the auto generated keys.

Specified by:

execWriteRequestWithKeys in class AbstractLoadBalancer

Parameters:

request - the request to execute

metadataCache - the metadataCache if any or null

Returns:

auto generated keys.

Throws:

AllBackendsFailedException - if all backends failed to execute the request

java.sql.SQLException - if an error occurs

execWriteRequest

private AbstractTask execWriteRequest(AbstractWriteRequest request,
                                      boolean useKeys,
                                      MetadataCache metadataCache)
                               throws AllBackendsFailedException,
                                      java.sql.SQLException

Common code for execWriteRequest(AbstractWriteRequest) and execWriteRequestWithKeys(AbstractWriteRequest).

Note that macros are processed here.

The result is given back in AbstractTask.getResult().

Parameters:

request - the request to execute

useKeys - true if this must give an auto generated keys ResultSet

metadataCache - the metadataCache if any or null

Throws:

AllBackendsFailedException - if all backends failed to execute the request

java.sql.SQLException - if an error occurs

execReadRequest

public abstract ControllerResultSet execReadRequest(SelectRequest request,
                                                    MetadataCache metadataCache)
                                             throws java.sql.SQLException

Implementation specific load balanced read execution.

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

executeRequestOnBackend

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

Execute a read request on the selected backend.

Parameters:

request - the request to execute

backend - the backend that will execute the request

metadataCache - a metadataCache if any or null

Returns:

the ResultSet

Throws:

java.sql.SQLException - if an error occurs

UnreachableBackendException

executeStoredProcedureOnBackend

protected ControllerResultSet executeStoredProcedureOnBackend(StoredProcedure proc,
                                                              DatabaseBackend backend,
                                                              MetadataCache metadataCache)
                                                       throws java.sql.SQLException,
                                                              UnreachableBackendException

Execute a stored procedure on the selected backend.

Parameters:

proc - the stored procedure to execute

backend - the backend that will execute the request

metadataCache - the metadataCache if any or null

Returns:

the ResultSet

Throws:

java.sql.SQLException - if an error occurs

UnreachableBackendException

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(StoredProcedure)

callStoredProcedure

private AbstractTask callStoredProcedure(StoredProcedure proc,
                                         boolean isRead,
                                         MetadataCache metadataCache)
                                  throws java.sql.SQLException

Post the stored procedure call in the threads task list.

Note that macros are processed here.

Parameters:

proc - the stored procedure to call

isRead - true if the call returns a ResultSet

metadataCache - the metadataCache if any or null

Returns:

the task that has been executed (caller can get the result by calling getResult())

Throws:

java.sql.SQLException - if an error occurs

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 AllBackendsFailedException,
                     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:

AllBackendsFailedException - if all backends failed to perform the rollback

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

waitForAllWritesToBePostedOnBackendBlockingThreads

private void waitForAllWritesToBePostedOnBackendBlockingThreads()
                                                         throws java.sql.SQLException

Wait for all writes to be posted on BackendBlockingThreads by simply acquiring the RW lock in write and releasing it.

Throws:

java.sql.SQLException - if we fail to acquire the lock

waitForAllWritesToComplete

protected void waitForAllWritesToComplete(long transactionId)
                                   throws java.sql.SQLException

Waits for all writes of the given transaction in the blocking thread queue to complete before being able to complete the transaction.

Throws:

java.sql.SQLException - if a locking error occurs

waitForAllWritesToComplete

protected void waitForAllWritesToComplete(DatabaseBackend backend,
                                          long transactionId)
                                   throws java.sql.SQLException

Waits for all writes of the given transaction in the blocking thread queue of the given backend to complete before being able to complete the transaction.

Throws:

java.sql.SQLException - if we fail to acquire the lock

See Also:

executeRequestOnBackend(org.objectweb.cjdbc.common.sql.SelectRequest, org.objectweb.cjdbc.controller.backend.DatabaseBackend, org.objectweb.cjdbc.controller.cache.metadata.MetadataCache)

waitForAllWritesToComplete

protected void waitForAllWritesToComplete(DatabaseBackend backend)
                                   throws java.sql.SQLException

Waits for all writes in the blocking thread queue of the given backend to complete.

Throws:

java.sql.SQLException - if we fail to acquire the lock

See Also:

executeRequestOnBackend(org.objectweb.cjdbc.common.sql.SelectRequest, org.objectweb.cjdbc.controller.backend.DatabaseBackend, org.objectweb.cjdbc.controller.cache.metadata.MetadataCache)

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

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()

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()

getRaidb2Xml

public abstract java.lang.String getRaidb2Xml()

return xml formatted information about this raidb2 load balancer

Returns:

xml formatted string