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REQUIREMENT

engine.qos.publish.isVolatile

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Type NEW
Priority LOW
Status CLOSED
Topic XmlBlaster allows to mark messages as volatile
Des
cription

Using the QOS flag <expiration lifeTime='0' forceDestroy='false'/> allows to mark a published message as volatile. A volatile published message lives only until it is processed in the server and is erased immediately thereafter.

With a lifetime of zero seconds xmlBlaster checks when the message is published all subscribers which match. It is not visible thereafter. Such a message may reside in the callback queue of some subscribers for hours until the client retrieves it. This behavior is controlled by forceDestroy='false' (false is the default so the attribute can be omitted).

Example
any 
      
<qos>
   <expiration lifeTime='0'/>
</qos>
Example
Java 
      
import org.xmlBlaster.client.qos.PublishQos;

Global glob = Global.instance();
...

PublishQos publishQos = new PublishQos(glob);

publishQos.setVolatile(true);

con.publish(new MsgUnit(glob, "<key oid='HelloWorld2'/>",
                            "Hello World".getBytes(),
                            publishQos.toXml()));
Configure

NOTE: Configuration parameters are specified on command line (-someValue 17) or in the xmlBlaster.properties file (someValue=17). See requirement "util.property" for details.
Columns named Impl tells you if the feature is implemented.
Columns named Hot tells you if the configuration is changeable in hot operation.

See API org.xmlBlaster.client.qos.PublishQos
See API org.xmlBlaster.client.key.PublishKey
See TEST org.xmlBlaster.test.topic.TestTopicLifeCycle

This page is generated from the requirement XML file xmlBlaster/doc/requirements/engine.qos.publish.isVolatile.xml

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