VORB (Virtual Object Ring Buffer) Design Meeting
Data acquisition Data distribution Data processing
Monday December 17 - Tuesday December 18 2001
IGPP Munk Conference Room, Scripps Institution of Oceanography

Notes from the meeting provided by Michael Scharber

The goal of this meeting was to clarify what the VORB will be and how it will function within ROADNet. For those familiar, even casually, with the GSAC and/or SDSC's SRB (Storage Resource Broker) the concept of VORB should be easier to grasp. Essentially, it is a tiered (scalable), distributed, seamless user interface/data delivery mechanism for data collected in real-time. There are more or less four major components of the VORB concept:

1. A distributed network of participating real-time, or near real-time, data sources; the term "data logger" was used frequently by several participants to represent this component, although in reality the "data logger" could collect and provide data from several data sources (i.e individual sensors).
2. A distributed network of ORB (Object Ring Buffer) servers; ORBs will run identical software enabling the provision of real-time or near real-time data streams/packets from any number of specified data sources. The ORB receives said data via a specified port, expects data packets to be named a certain way, and doesn’t care about the internal content of the packets. The ORB then manages a cache (buffer) of these packets and provides a similar means of retrieving a particular requested set of packets (including those not yet received, as in a real-time stream) by clients. The buffer is managed by the local agency providing the ORB service, specifying conditions whereby packets are removed in a designated fashion to maintain appropriate operating conditions (most likely in a first to arrive first to leave fashion).
   
3. A distributed network of VORB (Virtual Object Ring Buffer) servers, although probably smaller in number than the network of ORBs; VORBs will run identical (or near-identical) software enabling the provision of ALL ORB-provided data and metadata to constituent users registered with the VORB. The VORB facilitates a seamless data-client interface for which the client/user needn't know exactly where, how, or by whom the data requested is being served. The VORB will receive client requests via a macro language—or set of APIs (to be determined), to the effect of various SPACE-TIME-ATTRIBUTE query parameters provided by the client. The client, in turn, will receive a combination of metadata, real-time data streams, database records, etc. from the VORB, depending on their request.

A heterogeneous set of VORB clients; VORB clients will be comprised of any number of interface methods (GUIs, command-line executables, APIs, etc). The purpose of each VORB client may be quite different from the others. Some may be focused on archiving certain data from the VORB. Some may be geared specifically to provide real-time data "flow" to users holding PDAs or small devices with embedded logic. Still others may be focused on information discovery and/or quality control. The underlying premise is that they all communicate with VORBs only, not with ORBs and not with data sources, thereby facilitating the "seamless," distributed nature of ROADNet.

Attendees:

Doug Alden, SIO
Yehuda Bock, SIO
Hans-Werner Braun, SDSC
Pablo Bryant, SDSU
Dan Cayan, SIO
Brent Gilmore, SIO
Carolyn Keen, SIO
Todd Hansen, SDSC
Paul Harvey, SIO
Bertram Ludaescher, SDSC
Lisa Lellie, SIO
Kent Lindquist, University of Alaska
John Orcutt, SIO
Jason Proctor, SDSU
Dan Quinlan, Consultant
Arcot Rajasekar, SDSC
Michael Scharber, SIO
Brian Steves, SDSU
Eric Terrill, SIO
Frank Vernon, SIO