<p>The number of seconds
between this JMS server's cycles of scanning local destinations for
expired messages. A value of <code>0</code> disables active scanning. A
very large scan interval effectively disables active scanning.</p>
<p>With scanning disabled, users still do not receive expired
messages and any expired messages that are discovered by other
system activities are removed. However, expired messages sitting in
idle destinations (such as an inactive queue or disconnected
durable subscriber) are not removed and continue to consume system
resources.</p>
<p>The scanning cycle for expired messages occurs as follows:</p>
<ul>
<li>
After the specified waiting period, the JMS server devotes a
separate thread to scan all of its local destinations for expired
messages.
</li>
<li>
After the scanning is completed, all located expired messages
are processed according to the specified Expiration Policy on the
destination (Discard, Log, or Redirect).
</li>
<li>
The entire process repeats after another specified waiting
period.
</li>
</ul>
<p><b>Note:</b>
Because a new scan does not start until the current one is
finished and until the specified waiting period ends, an expired
message could still remain in the system for the maximum scan
waiting period plus the amount of time it takes to perform the
scan.</p>
(Interface=weblogic.management.configuration.JMSServerMBean Attribute=getExpirationScanInterval)