org.objectweb.cjdbc.controller.scheduler
Class AbstractScheduler

java.lang.Object
  org.objectweb.cjdbc.controller.scheduler.AbstractScheduler

All Implemented Interfaces:

XmlComponent

Direct Known Subclasses:

RAIDb0PassThroughLevelScheduler, RAIDb0PessimisticTransactionLevelScheduler, RAIDb1OptimisticQueryLevelScheduler, RAIDb1OptimisticTransactionLevelScheduler, RAIDb1PassThroughScheduler, RAIDb1PessimisticTransactionLevelScheduler, RAIDb1QueryLevelScheduler, RAIDb2PassThroughScheduler, RAIDb2PessimisticTransactionLevelScheduler, RAIDb2QueryLevelScheduler, SingleDBPassThroughScheduler, SingleDBPessimisticTransactionLevelScheduler

public abstract class AbstractScheduler

extends java.lang.Object

implements XmlComponent

The Request Scheduler should schedule the request according to a given policy.

The requests comes from the Request Controller and are sent later to the next ccontroller omponents (cache and load balancer).

Version:

1.0

Author:

Emmanuel Cecchet , Jean-Bernard van Zuylen

Field Summary

private java.lang.Object	endOfCurrentTransactions
private java.lang.Object	endOfCurrentWrites
protected static Trace	logger
private int	numberRead
private int	numberWrite
protected int	parsingGranularity
private int	pendingTransactions
private int	pendingWrites
protected int	raidbLevel
private int	sid
private boolean	suspendedTransactions
private boolean	suspendedWrites
private long	tid
private java.lang.Object	transactionSync
private java.lang.Object	writesSync

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

DOCTYPE_CONTROLLER, DOCTYPE_DB, XML_VERSION

Constructor Summary

AbstractScheduler(int raidbLevel, int parsingGranularity)
Default scheduler to assign scheduler RAIDb level, needed granularity and SQL macro handling (on the fly instanciation of NOW(), RAND(), ...).

Method Summary

long	begin(TransactionMarkerMetaData tm) Begin a new transaction and return the corresponding transaction identifier.
void	beginCompleted(long transactionId) Notify the completion of a begin command.
void	commit(TransactionMarkerMetaData tm) Commit a transaction.
void	commitCompleted(long transactionId) Notify the completion of a commit command.
protected abstract void	commitTransaction(long transactionId) Commit a transaction given its id.
int	getNumberRead()
int	getNumberWrite()
int	getParsingGranularity() Get the needed query parsing granularity.
int	getPendingTransactions()
int	getPendingWrites() Returns the number of pending writes.
int	getRAIDbLevel() Returns the RAIDbLevel.
java.lang.String[]	getSchedulerData() Returns live information on the scheduler
java.lang.String	getXml() Get information about the Request Scheduler in xml format
protected abstract java.lang.String	getXmlImpl()
int	incrementSavepointId() Increments the savepoint id for un-named savepoints
void	initializeTransactionId(long transactionId) Initialize the transaction id with the given value (usually retrieved from the recovery log).
boolean	isSuspendedTransactions()
boolean	isSuspendedWrites()
void	mergeDatabaseSchema(DatabaseSchema dbs) Merge the given DatabaseSchema with the current one.
abstract void	notifyStoredProcedureCompleted(StoredProcedure proc) Notify the completion of a stored procedure.
abstract void	notifyWriteCompleted(AbstractWriteRequest request) Notify the completion of a write statement.
void	readCompleted(SelectRequest request) Notify the completion of a read statement.
abstract void	readCompletedNotify(SelectRequest request) Notify the completion of a read statement.
void	releaseSavepoint(TransactionMarkerMetaData tm, java.lang.String name) Release a savepoint.
protected abstract void	releaseSavepointTransaction(long transactionId, java.lang.String name) Release a savepoint given its name from a transaction given its id.
void	resumeNewTransactions() Resume new transactions that were suspended by suspendNewTransactionsForCheckpoint().
void	resumeWrites() Resume the execution of write queries that were suspended by suspendWrites().
void	rollback(TransactionMarkerMetaData tm) Rollback a transaction.
void	rollback(TransactionMarkerMetaData tm, java.lang.String savepointName) Rollback a transaction to a savepoint.
void	rollbackCompleted(long transactionId) Notify the completion of a rollback command.
protected abstract void	rollbackTransaction(long transactionId) Rollback a transaction given its id.
protected abstract void	rollbackTransaction(long transactionId, java.lang.String savepointName) Rollback a transaction given its id to a savepoint given its name.
void	savepointCompleted(long transactionId) Notify the conpletion of a savepoint action.
abstract void	scheduleNonSuspendedStoredProcedure(StoredProcedure proc) Schedule a write request (implementation specific).
abstract void	scheduleNonSuspendedWriteRequest(AbstractWriteRequest request) Schedule a write request (implementation specific).
abstract void	scheduleReadRequest(SelectRequest request) Schedule a read request (implementation specific).
void	scheduleStoredProcedure(StoredProcedure proc) Schedule a write request.
void	scheduleWriteRequest(AbstractWriteRequest request) Schedule a write request.
void	setDatabaseSchema(DatabaseSchema dbs) Sets the DatabaseSchema of the current virtual database.
void	setParsingGranularity(int parsingGranularity) Set the needed query parsing granularity.
void	setRAIDbLevel(int raidbLevel) Sets the RAIDb level.
int	setSavepoint(TransactionMarkerMetaData tm) Set an unnamed savepoint.
void	setSavepoint(TransactionMarkerMetaData tm, java.lang.String name) Set a named savepoint.
protected abstract void	setSavepointTransaction(long transactionId, java.lang.String name) Set a savepoint given its name to a transaction given its id.
void	storedProcedureCompleted(StoredProcedure proc) Notify the completion of a stored procedure.
void	suspendNewTransactionsForCheckpoint() Suspend all calls to begin() until all current transactions are finished in order to store a checkpoint.
private void	suspendWriteIfNeeded(AbstractRequest request) Suspend write requests if suspendedWrites is active.
void	suspendWrites() Suspend all write queries.
void	writeCompleted(AbstractWriteRequest request) Notify the completion of a write statement.

Methods inherited from class java.lang.Object

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

Field Detail

raidbLevel

protected int raidbLevel

parsingGranularity

protected int parsingGranularity

tid

private long tid

sid

private int sid

suspendedTransactions

private boolean suspendedTransactions

pendingTransactions

private int pendingTransactions

transactionSync

private java.lang.Object transactionSync

endOfCurrentTransactions

private java.lang.Object endOfCurrentTransactions

suspendedWrites

private boolean suspendedWrites

pendingWrites

private int pendingWrites

writesSync

private java.lang.Object writesSync

endOfCurrentWrites

private java.lang.Object endOfCurrentWrites

logger

protected static Trace logger

numberRead

private int numberRead

numberWrite

private int numberWrite

Constructor Detail

AbstractScheduler

public AbstractScheduler(int raidbLevel,
                         int parsingGranularity)

Default scheduler to assign scheduler RAIDb level, needed granularity and SQL macro handling (on the fly instanciation of NOW(), RAND(), ...).

Parameters:

raidbLevel - RAIDb level of this scheduler

parsingGranularity - Parsing granularity needed by the scheduler

Method Detail

initializeTransactionId

public final void initializeTransactionId(long transactionId)

Initialize the transaction id with the given value (usually retrieved from the recovery log).

Parameters:

transactionId - new current transaction identifier

getParsingGranularity

public final int getParsingGranularity()

Get the needed query parsing granularity.

Returns:

needed query parsing granularity

setParsingGranularity

public final void setParsingGranularity(int parsingGranularity)

Set the needed query parsing granularity.

Parameters:

parsingGranularity - Parsing granularity needed by the scheduler

getPendingWrites

public final int getPendingWrites()

Returns the number of pending writes.

Returns:

int

getRAIDbLevel

public final int getRAIDbLevel()

Returns the RAIDbLevel.

Returns:

int

setRAIDbLevel

public final void setRAIDbLevel(int raidbLevel)

Sets the RAIDb level.

Parameters:

raidbLevel - The RAIDbLevel to set

setDatabaseSchema

public void setDatabaseSchema(DatabaseSchema dbs)

Sets the DatabaseSchema of the current virtual database. This is only needed by some schedulers that will have to define their own scheduler schema

Parameters:

dbs - a DatabaseSchema value

See Also:

SchedulerDatabaseSchema

mergeDatabaseSchema

public void mergeDatabaseSchema(DatabaseSchema dbs)

Merge the given DatabaseSchema with the current one.

Parameters:

dbs - a DatabaseSchema value

See Also:

SchedulerDatabaseSchema

incrementSavepointId

public int incrementSavepointId()

Increments the savepoint id for un-named savepoints

Returns:

the next savepoint Id

scheduleReadRequest

public abstract void scheduleReadRequest(SelectRequest request)
                                  throws java.sql.SQLException

Schedule a read request (implementation specific). This method blocks until the read can be executed.

Parameters:

request - Select request to schedule (SQL macros are already handled if needed)

Throws:

java.sql.SQLException - if a timeout occurs

readCompletedNotify

public abstract void readCompletedNotify(SelectRequest request)

Notify the completion of a read statement.

Parameters:

request - the completed request

readCompleted

public final void readCompleted(SelectRequest request)

Notify the completion of a read statement.

Parameters:

request - the completed request

scheduleWriteRequest

public final void scheduleWriteRequest(AbstractWriteRequest request)
                                throws java.sql.SQLException,
                                       RollbackException

Schedule a write request. This method blocks if the writes are suspended. Then the number of pending writes is updated and the implementation specific scheduleNonSuspendedWriteRequest function is called. SQL macros are replaced in the request if the scheduler has needSQLMacroHandling set to true.

Parameters:

request - Write request to schedule

Throws:

java.sql.SQLException - if a timeout occurs

RollbackException - if an error occurs

See Also:

scheduleNonSuspendedWriteRequest(AbstractWriteRequest)

scheduleNonSuspendedWriteRequest

public abstract void scheduleNonSuspendedWriteRequest(AbstractWriteRequest request)
                                               throws java.sql.SQLException,
                                                      RollbackException

Schedule a write request (implementation specific). This method blocks until the request can be executed.

Parameters:

request - Write request to schedule (SQL macros are already handled if needed)

Throws:

java.sql.SQLException - if a timeout occurs

RollbackException - if the transaction must be rollbacked

writeCompleted

public final void writeCompleted(AbstractWriteRequest request)

Notify the completion of a write statement.

This method updates the number of pending writes and calls the implementation specific notifyWriteCompleted function.

Finally, the suspendWrites() function is notified if needed.

Parameters:

request - the completed request

See Also:

notifyWriteCompleted(AbstractWriteRequest), suspendWrites()

notifyWriteCompleted

public abstract void notifyWriteCompleted(AbstractWriteRequest request)

Notify the completion of a write statement. This method does not need to be synchronized, it is enforced by the caller.

Parameters:

request - the completed request

See Also:

writeCompleted(AbstractWriteRequest)

scheduleStoredProcedure

public final void scheduleStoredProcedure(StoredProcedure proc)
                                   throws java.sql.SQLException,
                                          RollbackException

Schedule a write request. This method blocks if the writes are suspended. Then the number of pending writes is updated and the implementation specific scheduleNonSuspendedWriteRequest function is called. SQL macros are replaced in the request if the scheduler has needSQLMacroHandling set to true.

Parameters:

proc - Stored procedure to schedule

Throws:

java.sql.SQLException - if a timeout occurs

RollbackException - if an error occurs

See Also:

scheduleNonSuspendedStoredProcedure(StoredProcedure)

scheduleNonSuspendedStoredProcedure

public abstract void scheduleNonSuspendedStoredProcedure(StoredProcedure proc)
                                                  throws java.sql.SQLException,
                                                         RollbackException

Schedule a write request (implementation specific). This method blocks until the request can be executed.

Parameters:

proc - Stored procedure to schedule

Throws:

java.sql.SQLException - if a timeout occurs

RollbackException - if the transaction must be rollbacked

storedProcedureCompleted

public final void storedProcedureCompleted(StoredProcedure proc)

Notify the completion of a stored procedure.

This method updates the number of pending writes and calls the implementation specific notifyStoredProcedureCompleted function.

Finally, the suspendWrites() function is notified if needed.

Parameters:

proc - the completed stored procedure

See Also:

notifyStoredProcedureCompleted(StoredProcedure), suspendWrites()

notifyStoredProcedureCompleted

public abstract void notifyStoredProcedureCompleted(StoredProcedure proc)

Notify the completion of a stored procedure. This method does not need to be synchronized, it is enforced by the caller.

Parameters:

proc - the completed stored procedure

See Also:

storedProcedureCompleted(StoredProcedure)

suspendWriteIfNeeded

private void suspendWriteIfNeeded(AbstractRequest request)
                           throws java.sql.SQLException

Suspend write requests if suspendedWrites is active.

Parameters:

request - the request to suspend (a write request or a stored procedure)

Throws:

java.sql.SQLException - if the request timeout has expired

begin

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

Begin a new transaction and return the corresponding transaction identifier. This method is called from the driver when setAutoCommit(false) is called.

Parameters:

tm - The transaction marker metadata

Returns:

the transaction identifier

Throws:

java.sql.SQLException - if an error occurs

beginCompleted

public final void beginCompleted(long transactionId)

Notify the completion of a begin command.

Parameters:

transactionId - of the completed begin

commit

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

Commit a transaction.

Calls the implementation specific commitTransaction()

Parameters:

tm - The transaction marker metadata

Throws:

java.sql.SQLException - if an error occurs

See Also:

commitTransaction(long)

commitTransaction

protected abstract void commitTransaction(long transactionId)

Commit a transaction given its id.

Parameters:

transactionId - the transaction id

commitCompleted

public final void commitCompleted(long transactionId)

Notify the completion of a commit command.

Parameters:

transactionId - of the completed commit

rollback

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

Rollback a transaction.

Calls the implementation specific rollbackTransaction()

Parameters:

tm - The transaction marker metadata

Throws:

java.sql.SQLException - if an error occurs

See Also:

rollbackTransaction(long)

rollback

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

Rollback a transaction to a savepoint.

Calls the implementation specific rollbackTransaction()

Parameters:

tm - transaction marker metadata

savepointName - name of the savepoint

Throws:

java.sql.SQLException - if an error occurs

rollbackTransaction

protected abstract void rollbackTransaction(long transactionId)

Rollback a transaction given its id.

Parameters:

transactionId - the transaction id

rollbackTransaction

protected abstract void rollbackTransaction(long transactionId,
                                            java.lang.String savepointName)

Rollback a transaction given its id to a savepoint given its name.

Parameters:

transactionId - the transaction id

savepointName - the name of the savepoint

rollbackCompleted

public final void rollbackCompleted(long transactionId)

Notify the completion of a rollback command.

Parameters:

transactionId - of the rollback commit

setSavepoint

public final int setSavepoint(TransactionMarkerMetaData tm)
                       throws java.sql.SQLException

Set an unnamed savepoint.

Calls the implementation specific setSavepointTransaction()

Parameters:

tm - transaction marker metadata

Returns:

savepoint Id

Throws:

java.sql.SQLException - if an error occurs

setSavepoint

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

Set a named savepoint.

Calls the implementation specific setSavepointTransaction()

Parameters:

tm - transaction marker metadata

name - name of the savepoint

Throws:

java.sql.SQLException - if an error occurs

setSavepointTransaction

protected abstract void setSavepointTransaction(long transactionId,
                                                java.lang.String name)

Set a savepoint given its name to a transaction given its id.

Parameters:

transactionId - the transaction id

name - the name of the savepoint

releaseSavepoint

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

Release a savepoint.

Calls the implementation specific releaseSavepointTransaction()

Parameters:

tm - transaction marker metadata

name - name of the savepoint

Throws:

java.sql.SQLException - if an error occurs

releaseSavepointTransaction

protected abstract void releaseSavepointTransaction(long transactionId,
                                                    java.lang.String name)

Release a savepoint given its name from a transaction given its id.

Parameters:

transactionId - the transaction id

name - the name of the savepoint

savepointCompleted

public final void savepointCompleted(long transactionId)

Notify the conpletion of a savepoint action.

Parameters:

transactionId - the transaction identifier

suspendNewTransactionsForCheckpoint

public final void suspendNewTransactionsForCheckpoint()
                                               throws java.sql.SQLException

Suspend all calls to begin() until all current transactions are finished in order to store a checkpoint. This method returns when all pending transactions have finished.

New transactions remain suspended until resumeNewTransactions() is called.

Throws:

java.sql.SQLException - if an error occurs

See Also:

resumeNewTransactions()

resumeNewTransactions

public final void resumeNewTransactions()

Resume new transactions that were suspended by suspendNewTransactionsForCheckpoint().

See Also:

suspendNewTransactionsForCheckpoint()

suspendWrites

public void suspendWrites()
                   throws java.sql.SQLException

Suspend all write queries. This method blocks until all pending writes are completed.

Writes execution is resumed by calling resumeWrites()

Throws:

java.sql.SQLException - if an error occurs

See Also:

resumeWrites()

resumeWrites

public void resumeWrites()

Resume the execution of write queries that were suspended by suspendWrites().

See Also:

suspendWrites()

getXmlImpl

protected abstract java.lang.String getXmlImpl()

getXml

public java.lang.String getXml()

Get information about the Request Scheduler in xml format

Specified by:

getXml in interface XmlComponent

Returns:

String containing information in xml

getSchedulerData

public java.lang.String[] getSchedulerData()

Returns live information on the scheduler

Returns:

array of data

getNumberRead

public int getNumberRead()

Returns:

Returns the numberRead.

getNumberWrite

public int getNumberWrite()

Returns:

Returns the numberWrite.

getPendingTransactions

public int getPendingTransactions()

Returns:

Returns the pendingTransactions.

isSuspendedTransactions

public boolean isSuspendedTransactions()

Returns:

Returns the suspendedTransactions.

isSuspendedWrites

public boolean isSuspendedWrites()

Returns:

Returns the suspendedWrites.