org.objectweb.cjdbc.controller.loadbalancer.raidb2
Class RAIDb2ec_WRR

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
                  org.objectweb.cjdbc.controller.loadbalancer.raidb2.RAIDb2ec
                      org.objectweb.cjdbc.controller.loadbalancer.raidb2.RAIDb2ec_WRR

All Implemented Interfaces:

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

public class RAIDb2ec_WRR

extends RAIDb2ec

RAIDb-2 Weighted Round Robin load balancer with error checking.

This load balancer tolerates byzantine failures of databases. The read requests coming from the request manager are sent to multiple backend nodes and the results are compared. Write requests are broadcasted to all backends.

Version:

1.0

Author:

Emmanuel Cecchet , Julie Marguerite

Nested Class Summary

Nested classes inherited from class javax.management.StandardMBean

Field Summary

private java.util.HashMap

backends

Fields inherited from class org.objectweb.cjdbc.controller.loadbalancer.raidb2.RAIDb2ec

backendReadThreads, errorCheckingPolicy, logger, nbOfConcurrentReads

Fields inherited from class org.objectweb.cjdbc.controller.loadbalancer.raidb2.RAIDb2

backendBlockingThreads, backendBlockingThreadsRWLock, backendNonBlockingThreads, backendNonBlockingThreadsRWLock, createTablePolicy, 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

RAIDb2ec_WRR(VirtualDatabase vdb, WaitForCompletionPolicy waitForCompletionPolicy, CreateTablePolicy createTablePolicy, ErrorCheckingPolicy errorCheckingPolicy, int nbOfConcurrentReads)
Creates a new RAIDb-2 weighted round robin with error checking request load balancer.

Method Summary

ControllerResultSet	execReadOnlyReadStoredProcedure(StoredProcedure proc, MetadataCache metadataCache) Not implemented.
ControllerResultSet	execReadRequest(SelectRequest request, MetadataCache metadataCache) Performs a read request.
java.lang.String	getInformation() Gets information about the request load balancer.
java.lang.String	getRaidb2Xml() return xml formatted information about this raidb2 load balancer
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.raidb2.RAIDb2ec

disableBackend, enableBackend, getXmlImpl

Methods inherited from class org.objectweb.cjdbc.controller.loadbalancer.raidb2.RAIDb2

begin, commit, execReadStoredProcedure, executeRequestOnBackend, executeStoredProcedureOnBackend, execWriteRequest, execWriteRequestWithKeys, execWriteStoredProcedure, getNumberOfEnabledBackends, releaseSavepoint, rollback, rollback, setSavepoint, waitForAllWritesToComplete, waitForAllWritesToComplete, waitForAllWritesToComplete

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

backends

private java.util.HashMap backends

Constructor Detail

RAIDb2ec_WRR

public RAIDb2ec_WRR(VirtualDatabase vdb,
                    WaitForCompletionPolicy waitForCompletionPolicy,
                    CreateTablePolicy createTablePolicy,
                    ErrorCheckingPolicy errorCheckingPolicy,
                    int nbOfConcurrentReads)
             throws java.lang.Exception

Creates a new RAIDb-2 weighted round robin with error checking request load balancer.

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

errorCheckingPolicy - Policy to apply for error checking.

nbOfConcurrentReads - Number of concurrent reads allowed

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

Specified by:

execReadRequest in class RAIDb2

Parameters:

request - an SelectRequest

metadataCache - cached metadata to use to construct the result set

Returns:

the corresponding java.sql.ResultSet

Throws:

java.sql.SQLException - if an error occurs

See Also:

RAIDb2.execReadRequest(SelectRequest, MetadataCache)

execReadOnlyReadStoredProcedure

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

Not implemented.

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)

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)

getInformation

public java.lang.String getInformation()

Gets information about the request load balancer.

Specified by:

getInformation in interface AbstractLoadBalancerMBean

Specified by:

getInformation in class AbstractLoadBalancer

Returns:

String containing information

getRaidb2Xml

public java.lang.String getRaidb2Xml()

Description copied from class: RAIDb2

return xml formatted information about this raidb2 load balancer

Specified by:

getRaidb2Xml in class RAIDb2

Returns:

xml formatted string

See Also:

RAIDb2.getRaidb2Xml()