flowControl

The flowControl property specifies the target maximum size the server can use to store pending messages for the destination. Should the number of messages exceed the maximum, the server will slow down the producers to the rate required by the message consumers.

This is useful when message producers send messages much more quickly than message consumers can consume them. Unlike the behavior established by the overflowPolicy property, flowControl never discards messages or generates errors back to producer.

You can set flowControl using the form:

   flowControl=size[KB|MB|GB]

where size is the maximum number of bytes.

You can optionally include a KB, MB or GB after the number to specify kilobytes, megabytes, or gigabytes, respectively. For example:

   flowControl=1000KB

Means 1000 kilobytes.

For queues, flow control is engaged when the cumulative size of pending messages in the queue exceeds the target maximum size.

For topics, flow control is engaged when the cumulative size of pending messages for any one of the topic's durable subscribers exceeds the target maximum size.

If you specify the flowControl property without a value, the target maximum size is set to 256KB.

The flow_control parameter in tibemsd.conf file must be set to enabled before the value in this property is enforced by the server. See Flow Control for more information about flow control.