NOAO VOEvent Services and Clients

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THE US NATIONAL VIRTUAL OBSERVATORY
NOAO VOEvent Services and Clients
Phillip Warner, Rob Seaman, Chris Smith NOAO
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Purpose

• NVO Research Initiative
• Publish events from ESSENCE survey at NOAO
• http//www.ctio.noao.edu/wproject
• Type Ia SN search and follow-up
• 200 over a five-year period
• Redshift 0.15 to 0.75
• VRI photometry supplemented with observations
  from Keck, MMT, Magellan, Gemini and VLT
• collaboration with Alasdair Allan and RoboNet-1.0
  to follow-up brighter SNe photometrically
• Another run coming up this fall

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Purpose

• NVO Research Initiative
• Create supporting software infrastructure
• Authoring client
• Publisher
• Repository
• Relay
• Subscription client
• Goals
• Configurable
• Extensible
• Distributable

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Technologies Used?

• JBoss
• EJB 3.0 as DAO
• Hibernate (JPA) as ORM
• PostgreSQL for database backend
• Tomcat
• Spring MVC for ease of configuration
• vTCP
• v vanilla, or length protocol
• Specify length of packet, then packet data

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Components Author

• Event submission
• Tomcat
• Current implementation
• Spring MVC for configurability
• Currently basic submission
• You write the packet
• Copy/paste into web form
• Near future
• Better web form
• Standalone client using an API

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Components Publisher

• Accepts events from authors
• Event packet validation
• ID generation
• Current implementation
• Hibernate/PostgreSQL
• Goal is configurability
• Support for multiple event sources
• Near-term support includes ESSENCE events only
• Longer-term
• support multiple event sources

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Components Repository

• Event storage
• Enable query support
• Current implementation
• Simple repository
• Minimal metadata
• Near future
• A bit more complex than simple
• Support for queries

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Components Relay

• Event forwarding
• Current implementation
• Independent socket implementation
• vTCP vanilla
• backbone communication
• Near future?
• basically finished

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Components Subscriber

• Listening for events
• Current implementation
• Simple, uses vTCP
• Near future
• RSS
• Configurable subscriptions
• Server-side filtering

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Configurable

• Spring MVC
• Configuration through XML
• No coding required
• Assumes valid and proper implementation
• Spring container deployment
• Mix-and-match components
• Deploy only those services you need

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Extensible

• API for plugins
• Requires further iteration, but the concept and
  capability exists
• Interface-based
• Replace distributed components with custom
  components

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Distribution and Future Work

• Will provide full access to source and binaries
  and API documentation
• http//voevent.noao.edu
• Future work
• Decouple further from specific technologies
• JBoss and (maybe) Tomcat
• Support for other databases (simple)s
• Rich clients
• Authors
• Subscription clients