JMS Distributed Topic --> Configuration --> Thresholds and Quotas

Bytes Maximum

The maximum bytes quota (total amount of bytes) that can be stored on distributed topic members. The default value of -1 specifies that there is no WebLogic-imposed limit on the number of bytes that can be stored in the destination. However, excessive bytes volume can cause memory saturation, so this value should correspond to the total amount of available system memory relative to the rest of your application load.

Range of Values: >= BytesThresholdHigh

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

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

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: BytesMaximum

Minimum: -1

Maximum: 9223372036854775807

Default: -1

Dynamic: yes

Bytes Threshold High

The upper threshold value that triggers events based on the number of bytes stored on distributed topic members. If the number of bytes exceeds this threshold, the triggered events are:

• Log Messages - A message is logged on the server indicating a high threshold condition.

• Bytes Paging - If bytes paging is enabled (and a paging store has been configured), then destination-level bytes paging is started.

• Flow Control - If flow control is enabled, the destination becomes armed and instructs producers to begin decreasing their message flow.

A value of -1 specifies that bytes paging, flow control, and threshold log messages are disabled for the destination. However, if a JMS template is specified for distributed queue members, then -1 implies that the value will come from the template.

Range of Values: <= BytesMaximum; >BytesThresholdLow

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

Note: Bytes paging cannot be dynamically disabled by resetting the value to -1. To dynamically disable paging, you could set the value to a very large number, so that paging would not be triggered.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: BytesThresholdHigh

Minimum: -1

Maximum: 9223372036854775807

Default: -1

Dynamic: yes

Bytes Threshold Low

The lower threshold value that triggers events based on the number of bytes stored on distributed topic members. If the number of bytes falls below this threshold, the triggered events are:

• Log Messages - A message is logged on the server indicating that the threshold condition has cleared.

• Bytes Paging - If bytes paging is enabled, paging is stopped (if paging is occurring).

• Flow Control - If flow control is enabled, the destination becomes disarmed and instructs producers to begin increasing their message flow.

A value of -1 specifies that bytes paging, flow control, and threshold log messages are disabled for the destination. However, if a JMS template is specified for distributed topic members, then -1 implies that the value will come from the template.

Range of Values: < BytesThresholdHigh

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: BytesThresholdLow

Minimum: -1

Maximum: 9223372036854775807

Default: -1

Dynamic: yes

Bytes Paging Enabled

Specifies whether bytes paging is enabled on the distributed topic for temporarily swapping message bodies out from memory when a topic member's message load reaches a specified threshold.

• If the check box is cleared (false), bytes paging is disabled for the distributed topic.

• If the check box is selected (true), and if a paging store has been configured for the JMS Server, and both the BytesThresholdLow and BytesThresholdHigh attribute values are greater than -1, then bytes paging is enabled for the distributed topic.

Note: If no value is defined, then this setting defaults to false and bytes paging is disabled for the template's destinations -- unless the destination setting overrides the template.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: BytesPagingEnabled

Default: false

Valid values:

• true

• false

Messages Maximum

The maximum message quota (total amount of messages) that can be stored on distributed topic members. The default value of -1 specifies that there is no WebLogic-imposed limit on the number of messages that can be stored in the destination. However, excessive message volume can cause memory saturation, so this value should correspond to the total amount of available system memory relative to the rest of your application load.

Range of Values: >= MessagesThresholdHigh

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

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

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: MessagesMaximum

Minimum: -1

Maximum: 9223372036854775807

Default: -1

Dynamic: yes

Messages Threshold High

The upper threshold value that triggers events based on the number of messages stored on distributed topic members. If the number of messages exceeds this threshold, the triggered events are:

• Log Messages - A message is logged on the server indicating a high threshold condition.

• Messages Paging - If messages paging is enabled (and a paging store has been configured), then destination-level messages paging is started.

• Flow Control - If flow control is enabled, the destination becomes armed and instructs producers to begin decreasing their message flow.

A value of -1 specifies that messages paging, flow control, and threshold log messages are disabled for the destination. However, if a JMS template is specified for distributed queue members, then -1 implies that the value will come from the template.

Range of Values: <= MessagesMaximum; >MessagesThresholdLow

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

Note: Messages paging cannot be dynamically disabled by resetting the value to -1. To dynamically disable paging, you could set the value to a very large number, so that paging would not be triggered.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: MessagesThresholdHigh

Minimum: -1

Maximum: 9223372036854775807

Default: -1

Dynamic: yes

Messages Threshold Low

The lower threshold value that triggers events based on the number of messages stored on distributed topic members. If the number of messages falls below this threshold, the triggered events are:

• Log Messages - A message is logged on the server indicating that the threshold condition has cleared.

• Messages Paging - If messages paging is enabled, paging is stopped (if paging is occurring).

• Flow Control - If flow control is enabled, the destination becomes disarmed and instructs producers to begin increasing their message flow.

A value of -1 specifies that messages paging, flow control, and threshold log messages are disabled for the distributed queue member. However, if a JMS template is specified for distributed queue members, then -1 implies that the value will come from the template.

Range of Values: < MessagesThresholdHigh

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: MessagesThresholdLow

Minimum: -1

Maximum: 9223372036854775807

Default: -1

Dynamic: yes

Maximum Message Size

The maximum number of bytes allowed for messages on distributed topic members. The size includes the message body, any user-defined properties, and the user-defined JMS header fields: JMSCorrelationID and JMSType.

Producers sending messages that exceed the configured maximum message size for the distributed queue receive a ResourceAllocationException.

The maximum message size is only enforced for the initial production of a message. Messages that are redirected to an error destination or forwarded to a member of a distributed destination are not checked for size. For instance, if a destination and its corresponding error destination are configured with a maximum message size of 128K bytes and 64K bytes, respectively, a message of 96K bytes could be redirected to the error destination (even though it exceeds the 64K byte maximum), but a producer could not directly send the 96K byte message to the error destination.

This attribute is dynamically configurable, but only incoming messages are impacted; stored messages are not impacted.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: MaximumMessageSize

Minimum: -1

Maximum: 2147483647

Default: 2147483647

Dynamic: yes

Messages Paging Enabled

Specifies whether messages paging is enabled on the distributed topic for temporarily swapping message bodies out from memory when a topic member's messages load reaches a specified threshold.

• If the check box is cleared (false), messages paging is disabled for the distributed topic members.

• If the check box is selected (true), and if a paging store has been configured for the JMS Server, and both the MessagesThresholdLow and MessagesThresholdHigh attribute values are greater than -1, then messages paging is enabled for the distributed topic members.

Note: If no value is defined, this setting defaults to false and messages paging is disabled for the template's destinations -- unless the destination setting overrides the template.

MBean: weblogic.management.
configuration.
JMSTemplateMBean

Attribute: MessagesPagingEnabled

Default: false

Valid values:

• true

• false