QuotaBean


Overview  |   Related MBeans  |   Attributes  |   Operations

Overview

Quota beans control the allotment of system resources available to destinations. For example, the number of bytes a destination is allowed to store can be configured with a QuotaBean.

       
Security rolesThe following roles have read, write, and invoke permission for all non-encrypted attributes and operations in this MBean:
  • Deployer
Fully Qualified Interface NameIf you use the getMBeanInfo operation in MBeanTypeServiceMBean, supply the following value as this MBean's fully qualified interface name:
weblogic.j2ee.descriptor.wl.QuotaBean
Factory Methods No factory methods. Instances of this MBean are created automatically.


Attributes

This section describes the following attributes:


BytesMaximum

The total number of bytes that can be stored in a destination that uses this quota.

A value of zero means that no messages can be placed on a destination without exceeding the quota. A value of -1 prevents WebLogic Server from imposing a limit.

Because excessive bytes volume can cause memory saturation, Oracle recommends that the maximum corresponds to the amount of system memory that is available after accounting for the rest of your application load.

No consideration is given to messages that are pending; that is, messages that are in-flight, delayed, or otherwise inhibited from delivery still count against the message and/or bytes quota.This attribute is dynamic and can be changed at any time. If the quota is lowered and the quota object is now over quota, then subsequent requests for quota will be denied until quota is available. If the quota is raised, then this may allow the quota object to satisfy existing requests for quota.

Note: If a JMS template is used for distributed destination members, then this maximum applies only to those specific members and not the distributed destination set as a whole.

       
Privileges Read/Write
Typelong
Default Value9223372036854775807
Minimum value-1
Maximum value9223372036854775807

MessagesMaximum

The total number of messages that can be stored in a destination that uses this quota.

A value of zero means that no messages can be placed on a destination without exceeding the quota. A value of -1 prevents WebLogic Server from imposing a limit.

Because excessive bytes volume can cause memory saturation, Oracle recommends that the maximum corresponds to the amount of system memory that is available after accounting for the rest of your application load.

No consideration is given to messages that are pending; that is, messages that are in-flight, delayed, or otherwise inhibited from delivery still count against the message and/or bytes quota.This attribute is dynamic and can be changed at any time. If the quota is lowered and the quota object is now over quota, then subsequent requests for quota will be denied until quota is available. If the quota is raised, then this may allow the quota object to satisfy existing requests for quota.

Note: If a JMS template is used for distributed destination members, then this maximum applies only to those specific members and not the distributed destination set as a whole.

       
Privileges Read/Write
Typelong
Default Value9223372036854775807
Minimum value-1
Maximum value9223372036854775807

Name

The name of this entity, represented in XML as an attribute.

Many of the elements within the JMS module are named entities. All of the named entities encased by a type in the XML file must be unique. This is the identifier used to delineate a particular entity within the JMS module.

This attribute cannot be modified externally from the module (for example, with a deployment plan) because it may be used inside the module referentially.

       
Privileges Read/Write
Typejava.lang.String

Notes

Optional information that you can include to describe this named JMS descriptor bean.

JMS module saves this note in the JMS descriptor file as XML PCDATA. All left angle brackets (<) are converted to the XML entity &lt;. Carriage returns/line feeds are preserved.

Note:

If you create or edit a note from the Administration Console, the Administration Console does not preserve carriage returns/line feeds.

       
Privileges Read/Write
Typejava.lang.String

Policy

For destinations that use this quota, this policy determines whether to deliver smaller messages before larger ones when a destination has exceeded its message quota.

FIFO (first-in, first-out) indicates that requests for quota are submitted in the order they are received. If a given request for quota cannot be satisfied, and the client requesting the quota is willing to wait, then that request will block all other requests for quota until the request is satisfied or times out. This prevents smaller messages from being delivered when larger requests are already waiting for space.

Preemptive indicates that subsequent requests can preempt previously unsatisfied requests. That is, if there is sufficient quota for the current request, then that space is used even if there are other requests waiting for quota. When quota is limited, the Preemptive policy can result in the starvation of larger requests.

       
Privileges Read/Write
Typejava.lang.String
Default ValueFIFO
Legal Values
  • FIFO
  • Preemptive

Shared

Indicates whether this quota is shared by multiple destinations that refer to it.

If Shared is enabled (the default), all destinations referring to the quota object compete for resources the resources defined by that object. If one destination consumes a large number of messages or bytes, then this will prevent other destinations from obtaining quota.

If Shared is disabled, the quota object behaves as a template. Each destination referring to the quota object gets its own internal instance of the object for tracking quota.

Destinations within the same JMS module may share quotas in any way they want. However, quota sharing only takes place for destinations within the same JMS server. In other words, if destinations X and Y both share the same quota Q, and the quota Q has Shared enabled, then X and Y will only share quota if both are deployed to the same JMS server.

       
Privileges Read/Write
Typeboolean
Default Valuetrue


Operations

This section describes the following operations:


    isSet

    Return true if the given property has been explicitly set in this bean.

       
    Operation Name"isSet"
    ParametersObject [] {  propertyName }

    where:

    • propertyName is an object of type java.lang.String that specifies:

      property to check

    SignatureString [] { "java.lang.String" }
    Returns boolean
    Exceptions
    • java.lang.IllegalArgumentException
      IllegalArgumentException if propertyName is not a recognized property

    unSet

    Restore the given property to its default value.

       
    Operation Name"unSet"
    ParametersObject [] {  propertyName }

    where:

    • propertyName is an object of type java.lang.String that specifies:

      property to restore

    SignatureString [] { "java.lang.String" }
    Returns void
    Exceptions
    • java.lang.IllegalArgumentException
      UnsupportedOperationException if called on a runtime implementation.