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Quota: Configuration
Configuration Options Related Tasks Related Topics
Quotas are used to control the allotment of system resources available to destinations. For example, a quota can determine the number of bytes or messages that a destination is allowed to store.
Use this page to define a quota configuration for the current JMS module.
Configuration Options
Name Description Name The name of this quota object.
MBean Attribute (Does not apply to application modules) :
QuotaBean.NameChanges take effect after you redeploy the module or restart the server.
Bytes Maximum 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.
MBean Attribute (Does not apply to application modules) :
QuotaBean.BytesMaximumMinimum value:
-1Maximum value:
9223372036854775807Messages Maximum 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.
MBean Attribute (Does not apply to application modules) :
QuotaBean.MessagesMaximumMinimum value:
-1Maximum value:
9223372036854775807Policy 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.
Preemptiveindicates 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.MBean Attribute (Does not apply to application modules) :
QuotaBean.PolicyShared Indicates whether this quota is shared by multiple destinations that refer to it.
If
Sharedis 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
Sharedis 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
Sharedenabled, then X and Y will only share quota if both are deployed to the same JMS server.MBean Attribute (Does not apply to application modules) :
QuotaBean.SharedChanges take effect after you redeploy the module or restart the server.
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