Uniform Distributed Topic: Configuration: Thresholds and Quotas

Use this page to define upper and lower byte and/or message thresholds for the uniform distributed topic. Exceeding these thresholds will trigger events such as generating log messages and starting message flow control. You can also specify a maximum size allowed for messages on the queue and select a pre-configured quota, which determines the maximum number of bytes or messages that the distributed topic is allowed to store to conserve memory use.

A JMS server can also manage thresholds and certain quota settings for all destinations in a JMS module targeted to that JMS server.

Configuration Options

Name	Description
Bytes Threshold High	The upper threshold (total number of bytes in this destination) that triggers logging or flow control events. The value of java.lang.Long.MAX_VALUE disables logging and flow control events for the destination. 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. Flow Control If flow control is enabled, the destination becomes armed and instructs producers to begin decreasing their message flow. Range of Values: <= BytesMaximum; >BytesThresholdLow Any change to this threshold affects only incoming messages; stored messages are not affected. MBean Attribute (Does not apply to application modules): `ThresholdParamsBean.BytesHigh` Minimum value: `0` Maximum value: `9223372036854775807`
Bytes Threshold Low	The lower threshold (total number of bytes in this destination) that triggers logging or flow control events. The value of java.lang.Long.MAX_VALUE disables logging and flow control events for the destination. If the number of bytes falls below this threshold, the triggered events are: Log Messages A message is logged on the server indicating a low threshold condition. Flow Control If flow control is enabled, the destination becomes disarmed and instructs producers to begin increasing their message flow. Range of Values: < BytesThresholdHigh Any change to this threshold affects only incoming messages; stored messages are not affected. MBean Attribute (Does not apply to application modules): `ThresholdParamsBean.BytesLow` Minimum value: `0` Maximum value: `9223372036854775807`
Messages Threshold High	The upper threshold (total number of messages in this destination) that triggers logging or flow control events. The value of java.lang.Long.MAX_VALUE disables logging and flow control events for the destination. 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. Flow Control If flow control is enabled, the destination becomes armed and instructs producers to begin decreasing their message flow. Range of Values: <= MessagesMaximum; >MessagesThresholdLow Any change to this threshold affects only incoming messages; stored messages are not affected. MBean Attribute (Does not apply to application modules): `ThresholdParamsBean.MessagesHigh` Minimum value: `0` Maximum value: `9223372036854775807`
Messages Threshold Low	The lower threshold (total number of messages in this destination) that triggers logging or flow control events. The value of java.lang.Long.MAX_VALUE disables logging and flow control events for the destination. If the number of messages falls below this threshold, the triggered events are: Log Messages A message is logged on the server indicating a low threshold condition. Flow Control If flow control is enabled, the destination becomes disarmed and instructs producers to begin increasing their message flow. Range of Values: < MessagesThresholdHigh Any change to this threshold affects only incoming messages; stored messages are not affected. MBean Attribute (Does not apply to application modules): `ThresholdParamsBean.MessagesLow` Minimum value: `0` Maximum value: `9223372036854775807`
Quota	A Quota controls 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 Quota. MBean Attribute (Does not apply to application modules): `DestinationBean.Quota`
Maximum Message Size	The maximum size of a message that is accepted from producers on this destination. The message 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 destination 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 Attribute (Does not apply to application modules): `DestinationBean.MaximumMessageSize` Minimum value: `0` Maximum value: `2147483647`