org.objectweb.cjdbc.controller.loadbalancer.raidb1
Class RAIDb1

java.lang.Object
  org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer
      org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1

Direct Known Subclasses:

RAIDb1_LPRF, RAIDb1_RR, RAIDb1_WRR, RAIDb1ec

public abstract class RAIDb1

extends AbstractLoadBalancer

RAIDb-1 load balancer.

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

Version:

1.0

Author:

Emmanuel Cecchet

Field Summary

protected java.util.ArrayList	backendBlockingThreads
protected ReadPrioritaryFIFOWriteLock	backendBlockingThreadsRWLock
protected java.util.ArrayList	backendNonBlockingThreads
protected ReadPrioritaryFIFOWriteLock	backendNonBlockingThreadsRWLock
private int	execWriteRequestResult
private java.sql.ResultSet	execWriteRequestWithKeysResult
protected static Trace	logger
private WaitForCompletionPolicy	waitForCompletionPolicy

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

parsingGranularity, raidbLevel, vdb

Constructor Summary

RAIDb1(VirtualDatabase vdb, WaitForCompletionPolicy waitForCompletionPolicy)
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) 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) Enables a Backend that was previously disabled.
abstract java.sql.ResultSet	execReadRequest(SelectRequest request) Perform a read request.
java.sql.ResultSet	execReadStoredProcedure(StoredProcedure proc) Call a stored procedure that returns a ResultSet.
protected java.sql.ResultSet	executeRequest(SelectRequest request, DatabaseBackend backend) Execute a read request on the selected backend.
int	execWriteRequest(AbstractWriteRequest request) Performs a write request.
private void	execWriteRequest(AbstractWriteRequest request, boolean useKeys) Common code for execWriteRequest(AbstractWriteRequest) and execWriteRequestWithKeys(AbstractWriteRequest).
java.sql.ResultSet	execWriteRequestWithKeys(AbstractWriteRequest request) 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.
protected abstract java.lang.String	getRaidb1Xml() Surrounding raidb1 tags can be treated by getXmlInformation above, but more detailed content have to be returned by the method getRaidb1Xmlbelow.
java.lang.String	getXmlInformation() Get information about the Request Load Balancer in xml
java.lang.String	getXmlWaitPolicy() get xml formatted wait policy according to c-jdbc.dtd
void	rollback(TransactionMarkerMetaData tm) Rollbacks a transaction.
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, int 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(int 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

getInformation, getParsingGranularity, getRAIDbLevel, setParsingGranularity, setRAIDbLevel, setWeight

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

private WaitForCompletionPolicy waitForCompletionPolicy

logger

protected static Trace logger

execWriteRequestResult

private int execWriteRequestResult

execWriteRequestWithKeysResult

private java.sql.ResultSet execWriteRequestWithKeysResult

Constructor Detail

RAIDb1

public RAIDb1(VirtualDatabase vdb,
              WaitForCompletionPolicy waitForCompletionPolicy)
       throws java.sql.SQLException

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?

Throws:

java.sql.SQLException - if an error occurs

Method Detail

getNbToWait

private final 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

execReadRequest

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

Description copied from class: AbstractLoadBalancer

Perform a read request. It is up to the implementation to choose to which backend node(s) this request should be sent.

Specified by:

execReadRequest in class AbstractLoadBalancer

Parameters:

request - an SelectRequest

Returns:

the corresponding java.sql.ResultSet

Throws:

java.sql.SQLException - if an error occurs

See Also:

AbstractLoadBalancer.execReadRequest(SelectRequest)

executeRequest

protected java.sql.ResultSet executeRequest(SelectRequest request,
                                            DatabaseBackend backend)
                                     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

Returns:

the ResultSet

Throws:

java.sql.SQLException - if an error occurs

execWriteRequest

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

Performs a write request. This request is broadcasted to all nodes.

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 java.sql.ResultSet execWriteRequestWithKeys(AbstractWriteRequest request)
                                            throws 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

Returns:

auto generated keys.

Throws:

java.sql.SQLException - if an error occurs

execWriteRequest

private void execWriteRequest(AbstractWriteRequest request,
                              boolean useKeys)
                       throws java.sql.SQLException

Common code for execWriteRequest(AbstractWriteRequest) and execWriteRequestWithKeys(AbstractWriteRequest). The result is given back using member variables execWriteRequestResult and execWriteRequestWithKeysResult defined above.

Parameters:

request - the request to execute

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

Throws:

java.sql.SQLException - if an error occurs

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)

callStoredProcedure

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

Post the stored procedure call in the threads task list.

Parameters:

proc - the stored procedure to call

isRead - true if the call returns a ResultSet

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

waitForAllWritesToComplete

protected void waitForAllWritesToComplete(int 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

waitForAllWritesToComplete

protected void waitForAllWritesToComplete(DatabaseBackend backend,
                                          int 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

See Also:

executeRequest(SelectRequest, DatabaseBackend)

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

See Also:

executeRequest(SelectRequest, DatabaseBackend)

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

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()

getXmlWaitPolicy

public java.lang.String getXmlWaitPolicy()

get xml formatted wait policy according to c-jdbc.dtd

Returns:

xml formatted string of ""

getRaidb1Xml

protected abstract java.lang.String getRaidb1Xml()

Surrounding raidb1 tags can be treated by getXmlInformation above, but more detailed content have to be returned by the method getRaidb1Xmlbelow.

Returns:

content of Raidb1 xml