Jul
15
Written by:
Event Zero Administrator
7/15/2008 5:10 PM
Day 4 - DEBS 2008 (last day)
Last day of the conference. The heat is finally breaking a little bit and it appears the crowd has thinned out a bit (some folks must have headed out early). Some good material was presented today.
Keynonte: Meeting the challenges of mission-critical distributed event based systems with qos-enabled middleware and model driven engineering – Douglas Schmidt
The keynote today, by Douglas Schmidt from Vanderbilt University, covered the challenges of developing and maintaining Ultra-Large Scale (ULS) distributed systems and associated tools to assist in meeting those challenges. ULS systems typically follow serialized phasing starting with the system infrastructure very early on in the overall implementation ending with system integration & testing after the application development is finished which leads to surprises found relatively late in the cycle. This drives the need for system execution modeling (SEM) tools to express&validate design rules, ensure design conformance for proper deployment & configuration, and help analyze QoS concerns by allowing “what if” analysis before the system integration phase occurs. Managing the large configuration space for a ULS system consisting of XML application and middleware runtime configurations presents a unique set of challenges. While XML serves as a good general-purpose mechanism to describe a configuration and deliver it to a middleware platform – it is difficult to visualize and understand the implications of various configuration options as related to the behavior of the middleware platform (especially in a highly heterogeneous environment). Options Configuration Modeling Language (OCML) was discussed as an approach to define a configuration model and ensure consistency of option configurations across platforms.
Session 1: Modeling Event based systems
There were 3 academic presentations in this track. The first presentation covered a component oriented approach for modeling distributed event based (DEBs) applications using reactive component interfaces that describe both events generated and behavior of a component to provide structural, control, and runtime views. The next presentation discussed the topic of distributed automatic service composition using content-based publish subscribe to model service inputs and outputs. Service interfaces are mapped to publish/subscribe message to enable use of publish/subscribe matching to determine service compatibility and candidates for composition. The final presentation in this track covered hierarchical event-based system simulation and modeling using two new concepts (basic and network components) applied to the heterogeneous flow system specification (HFSS) to represent hybrid push/pull systems.
Session 2: Complex event processing and Streaming queries
4 presentations in this track – thought his was a very good bunch of presentations to wrap up the conference. The first presentation discussed event probability for derived events accounting for uncertainty at the event source. An algorithm based on Bayesian network representation was presented to derive new events and calculate the associated probability based on contributing uncertain events. The next presentation discussed how to increase throughput in an event stream processing (ESP) application using speculative processing and software transaction memory (STM) to perform parallel event processing in cases where sequential processing is required (ie. Order based derived state). STM and an event-specific extension (pre-assignment of timestamps) is used to ensure consistency for ordered processing by using transactions that can be rolled back and retried when unordered conditions are detected. The next presentation covered efficient execution of real-time continuous queries(RCQs) using adaptive processing to schedule queries and perform load shedding by dropping tuples using a feedback-based approach to select the tuples to drop. The final presentation was geared towards stream processing systems that maintain an intermediate cache of events in order to detect patterns of events and garbage collection of events that are no longer relevant. Temporal relevance is determined statically at compile time and used at query evaluation/run time to purge events that become irrelevant as time progresses.
Conference Wrapup
Conference organizers presented a wrapup/summary of the new things attempted at this conference along with a breakdown of the attendees by country, industry, and academia.
144 Attendees : 78 academic, 66 industry, 22 USA, 4 AUS
I thought the conference was an overall success. It was a good blend of academia and industry which provided a good bidirectional vehicle to share real world experiences with leading research in event processing. The conference was much more than I expected and I’ll be headed to Nashville for DEBS 2009! Having experienced 2008, I think that we will do our best to contribute and participate in the 2009 conference.
From a logistical standpoint, I think the conference went amazingly well especially given it was held in middle of the Rome maze. We had one miserable day with no air conditioning, but it wasn’t a disaster and I think the organizers did a good job finding an alternate venue. Finally, the conference catering was possibly the best I’ve ever had. Hats to the Italians and their hospitality.
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