<p>The amount of memory (in bytes) that this JMS server can use
to store message bodies before it writes them to disk.
When the JMS server writes the message bodies to disk, it clears
them from memory.</p>
<p>A value of -1 (the default) specifies that the server will automatically
determine a size based on the maximum heap size of the JVM. This default
will be set to either one-third the maximum heap size, or 512 megabytes,
whichever is larger.</p>
<p>The larger the buffer, the more memory JMS will consume when
many messages are waiting on queues or topics. Once the buffer is
surpassed, JMS may write message bodies to the directory specified
by PagingDirectory in an effort to reduce memory usage below this
buffer.</p>
<p>Surpassing the buffer size does not stop the JMS server from
accepting new messages. It is still possible to run out of memory
if messages are arriving faster than they can be written to disk.
Users with high messaging loads who wish to support the highest
possible availability should consider setting a quota or setting a
threshold and enabling flow control.</p>
<p>Paging is always supported.</p>
(Interface=weblogic.management.configuration.JMSServerMBean Attribute=getMessageBufferSize)