The Processing Pattern Namespace

The Processing Pattern Namespace provides the ability to declaratively configure the Processing Pattern.

Namespace Content Handler

The implementation is provided by the com.oracle.coherence.patterns.processing.configuration.ProcessingPatternNamespaceHandler class.

Declaration

The common prefix used for this namespace in Cache Configurations is processing, however as with all XML namespace declarations this can be defined arbitrarily when declaring the namespace.

To use the namespace you should declare it as follows:

<cache-config xmlns:processing="class://com.oracle.coherence.patterns.processing.configuration.ProcessingPatternNamespaceHandler">

   ...

</cache-config>

Elements

The following section outlines the elements defined by this namespace, the most important of which are the <processing:cluster-config> and the <processing:extend-config> elements. These elements are typically incorporated into Coherence Cache Config <cache-config> elements.

Reference:

The following elements are defined by this namespace.

• attribute-match-policy
• attribute
• cluster-config
• composite-policy
• default-taskprocessor
• dispatchers
• extend-config
• local-executor-dispatcher
• logging-dispatcher
• random-policy
• round-robin-policy
• task-dispatcher
• taskprocessordefinition
• taskprocessors

<processing:attribute-match-policy>

The element will specifies that the attributes declared in a SubmissionConfiguration must match those defined by a TaskProcessor.

Used in:

This element is a child element of <processing:task-dispatcher>.

Example:

<processing:attribute-match-policy />

See Also:

• attribute
• taskprocessordefinition

<processing:attribute>

This element defines an attribute for a TaskProcessor.

Used in:

This element is a child element of <processing:taskprocessordefinition>.

Attributes:

The following attributes must be defined as part of this element:

• name

  The name of the attribute

Examples:

<processing:attribute name="attribute-name">attribute-value</processing:attribute>

<processing:attribute name="operating-system">WINDOWS</processing:attribute>

See Also:

• attribute-match-policy
• taskprocessordefinition

<processing:cluster-config>

This element specifies the configuration of a Processing Pattern Cluster Member.

Used in:

This element is to be defined as a child of a <cache-config> element with in an Oracle Coherence Cache Configuration file.

Child Elements:

Zero or more the following elements may be defined as a child element ofthis element:

• <processing:dispatchers>

  Specifies TaskDispatcher definitions.

• <processing:taskprocessors>

  Specifies TaskProcessor definitions.

<processing:composite-policy>

This elements defines a Task Dispatch policy that is the composition of two other Task Dispatch Policies.

The first policy is evaluated to select a subset of TaskProcessors, after which the second policy is used to further restrict tasks.

Used in:

This element is a child element of <processing:task-dispatcher>.

Child Elements:

Exactly two of the following elements must be defined as children of this element:

• <processing:attribute-match-policy>

  Specifies an Attribute Matching Task Dispatch Policy.

• <processing:composite-policy>

  Specifies a Composite Task Dispatch Policy.

• <processing:round-robin-policy>

  Specifies a Round Robin Task Dispatch Policy.

• <processing:random-policy>

  Specifies a Random Task Dispatch Policy.

• <instance>

  An Oracle Coherence <instance> element, defining an TaskDispatchPolicy to be used for instantiating a custom TaskDispatchPolicy implementation.

• <class-scheme>

  An Oracle Coherence <class-scheme> element, defining an TaskDispatchPolicy to be used for instantiating a custom TaskDispatchPolicy implementation.

Example:

<processing:composite-policy>
    <processing:attribute-match-policy />
    <processing:round-robin-policy />
</processing:composite-policy>

<processing:default-taskprocessor>

This element defines a default TaskProcessor.

Used in:

This element is a child element of <processing:taskprocessordefinition>.

Attributes:

The following attributes must be defined as part of this element:

• id (required)

  The unique identity of the TaskProcessor. This is used for logging and JMX instrumentation.

• threadpoolsize (required)

  The number of threads for the TaskProcessor. Each thread can execute a Task concurrently.

Example:

<processing:default-taskprocessor id="GridTaskProcessor" threadpoolsize="10" />

<processing:dispatchers>

This element defines the dispatcher configuration for a Processing Pattern Cluster Member.

The order of the child elements defines the order of Dispatcher evaluation

Used in:

This element is a child element of <processing:cluster-config>.

Child Elements:

Zero or more the following elements may be defined as a child element ofthis element:

• <processing:local-executor-dispatcher>

  Specifies a LocalExecutorDispatcher.

• <processing:logging-dispatcher>

  Specifies a LoggingDispatcher.

• <processing:task-dispatcher>

  Specifies a Task Dispatcher.

• <instance>

  An Oracle Coherence <instance> element, defining an Dispatcher to be used for instantiating a custom Dispatcher implementation.

• <class-scheme>

  An Oracle Coherence <class-scheme> element, defining an Dispatcher to be used for instantiating a custom Dispatcher implementation.

<processing:extend-config>

This element defines configuration for a Processing Pattern Extend Client, that of which may optionally participate and perform calculations on behalf of the Processing Pattern Cluster Members.

An Extend client can serve as a client to the processing pattern submitting work as well as execute tasks using TaskProcessors. However, it can't serve as a Dispatcher. That means that any processing pattern deployment needs Processing Pattern Cluster Members to do the dispatching.

Used in:

This element is to be defined as a child of a <cache-config> element with in an Oracle Coherence Cache Configuration file.

Child Elements:

The following elements may be defined as a child element ofthis element:

• <> (required)

  Specifies the Coherence Extend Client connection configuration.

• <processing:taskprocessors> (optional)

  Specifies the configuration of optional Extend Client-side TaskProcessors.

<processing:local-executor-dispatcher>

This element defines a LocalExecutorDispatcher as part of a Dispatcher chain.

A LocalExecutorDispatcher will accept Submissions containing payload that implements the Java Runnable or Callable interfaces.

The submitted Runnables/Callables will be executed on the node where the Dispatching takes place.

Used in:

This element is a child element of <processing:dispatchers>.

Attributes:

The following attribute must be defined a part of this element:

• displayname (required)

  The display name for the Dispatcher.

• threadpoolsize (required)

  The number of threads for the Dispatcher may use for concurrently executing Runnables/Callables.

<processing:logging-dispatcher>

This element defines a LoggingDispatcher as part of a Dispatcher chain.

A LoggingDispatcher logs Submissions to the java.util.logging Framework, instead of accepting them for execution. This allows other Dispatcher implementations defined in the <processing:dispatchers> to continue processing.

Used in:

This element is a child element of <processing:dispatchers>.

Attributes:

The following attribute must be defined a part of this element:

• displayname (required)

  The display name of the TaskDispatcher.

<processing:random-policy>

The element will specifies that a randomized approach for selecting an appropriate TaskProcessor to execute a submitted Task should be used.

Used in:

This element is a child element of <processing:task-dispatcher>.

Example:

<processing:random-policy />

<processing:round-robin-policy>

The element will specifies that a round-robin approach for selecting an appropriate TaskProcessor to execute a submitted Task should be used.

Used in:

This element is a child element of <processing:task-dispatcher>.

Example:

<processing:round-robin-policy />

<processing:task-dispatcher>

This element defines a TaskDispatcher in the Dispatcher chain.

A TaskDispatcher dispatches Tasks to TaskProcessors using according to a TaskDispatchPolicy.

A TaskDispatchPolicy must be specified as a child element to the TaskDispatcher. If no TaskDispatchPolicy is specified, the RoundRobinPolicy is used.

Used in:

This element is a child element of <processing:dispatchers>.

Attributes:

The following attribute must be defined a part of this element:

• displayname (required)

  The display name of the TaskDispatcher.

Child Elements:

One of the following elements must be defined as children of this element:

• <processing:attribute-match-policy>

  Specifies an Attribute Matching Task Dispatch Policy.

• <processing:composite-policy>

  Specifies a Composite Task Dispatch Policy.

• <processing:round-robin-policy>

  Specifies a Round Robin Task Dispatch Policy.

• <processing:random-policy>

  Specifies a Random Task Dispatch Policy.

• <instance>

  An Oracle Coherence <instance> element, defining an TaskDispatchPolicy to be used for instantiating a custom TaskDispatchPolicy implementation.

• <class-scheme>

  An Oracle Coherence <class-scheme> element, defining an TaskDispatchPolicy to be used for instantiating a custom TaskDispatchPolicy implementation.

<processing:taskprocessordefinition>

This element defines a TaskProcessor that of which may be used for executing Tasks dispatched by TaskDispatchers.

Used in:

This element is a child element of <processing:task-processors>.

Attributes:

The following attributes must be defined a part of this element:

• id (required)

  The unique identity for the TaskProcessor.

• displayname (required)

  The display name for the TaskProcessor.

• type (required)

  The type of the TaskProcessor indicates where it will be instantiated. There are two valid types:

  GRID indicating the TaskProcessor should be instantiated in every Cluster Member.

  SINGLE indicating that the TaskProcessor should be instantiated only in a single Cluster Member.

Child Elements:

One of the following elements must be defined as child of this element:

• <processing:default-taskprocessor>

  The default definition of a TaskProcessor.

• <instance>

  An Oracle Coherence <instance> element, defining an TaskProcessor to be used for instantiating a custom TaskProcessor implementation.

• <class-scheme>

  An Oracle Coherence <class-scheme> element, defining an TaskDispatchPolicy to be used for instantiating a custom TaskProcessor implementation.

Zero or more of the following elements may be defined as children of this element:

• <processing:attribute>

  An attribute that must be part of the Submission in order for the Task to be executed by the TaskProcessor when using the <processing:attribute-matching-policy>.

<processing:taskprocessors>

This element defines TaskProcessors that of which are used by TaskDispatchers for executing Tasks.

Used in:

This element is a child element ofeither <processing:cluster-config> or <processing:extend-config>.

Child Elements:

One of the following elements must be defined as child of this element:

• <processing:taskprocessordefinition>

  The definition of a TaskProcessor.

Example:

<processing:taskprocessors>
    <processing:taskprocessordefinition id="GridTaskProcessor"
                                        displayname="Grid Task Processor"
                                        type="GRID">

        <processing:default-taskprocessor id="GridTaskProcessor"
                                          threadpoolsize="10" />

        <processing:attribute name="operating-system">LINUX</processing:attribute>
    </processing:taskprocessordefinition>
</processing:taskprocessors>