V<TITLE> On QoS-Aware Publish-Subscribe</TITLE>

<H1>On QoS-Aware Publish-Subscribe</H1>

<EM>F. Araújo and L. Rodrigues</EM>

<P>
Selected sections of this report will be published in the Proceedings
of the International Workshop on Distributed Event-Based Systems,
Vienna, Austria, July, 2002. (In conjuction with the 22nd
International Conference on Distributed Computing Systems).
  
<P>

<H2>Abstract</H2> 
  This position paper addresses the issue of supporting
  quality of service (QoS) parameters in distributed publish-subscribe
  systems.  It advocates that QoS parameters should be handled using
  the same constructs as other information regarding events, such as
  their type or content. At the same time, we claim that the use of a
  consistent set of mechanisms should not preclude to decouple the
  specification of QoS properties from the specification of type,
  subject or content-based constraints.
<p>  
  We also advocate that QoS parameters should not be embedded on the
  type or content of the events. We show that some QoS parameters can
  only be computed in run-time, as they depend on dynamic aspects such
  as the location of the participants and the system load.
<p>  
  The paper proposes a model that supports the decoupling of QoS
  characterization from the event characterization while, at the same
  time, offers an uniform treatment of both aspects.
<p>

<em>Also available extended report <A
HREF="../reports/debs02.ps.gz">(gzip postscript)</A>, <A
HREF="../reports/debs02.pdf">(pdf)</A> .</em>

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<A HREF="../home.html">Lu&iacute;s Rodrigues</A>