Jul
2
Written by:
Event Zero Administrator
7/2/2008 2:50 PM
Another HOT day in Rome and a cab ride to somewhere near the venue The Dipartmento Di Informaica e Sistemistica. The cabdriver stopped, pointed over his shoulder, and said a few things in Italian. After about 15 mins more walking I found the Departminto di Informaica and proceed to the registration area. Many people were milling about, hanging out, helping, and getting help. They were very accommodating even in the middle of all the chaos. By now I could notice everyone was starting to form a nice sheen of sweat from the building heat. All of the sessions had about 40-50 attendees and there were dual sessions all day in each time slot. Today is “tutorial day” with two simultaneous tracks – I’m planning on going to presentations from each track.
The first session titled Events and Streams was lead by Sharma Chakravarthy from the University of Texas at Arlington. He discussed the evolution of event processing and how it evolved from various database management platforms (DBMS) . Event processing evolved from the same driving factors that lead to database triggers. A comparison of DBMS to DSMS (data stream management systems) was presented. In general, DSMS’s provide: transient relationships, continuous queries, sequential access, approximate results, and are geared towards realtime requirements. Continuous query modeling and measurements were presented comparing various scheduling algorithms (FIFO and chain) to look at the impact of latency and q size. The results presented indicated that each algorithm had impact positive and negative impact on the dimensions of q size and latency.
The next session was lead by Opher Etzion who presented various patterns related to event processing: business usage patterns, event processing function patterns, and patterns in detecting event patterns (this topic was the main focus of his presentation). He described an EPN as a collection of events and their associated flows. An agent represents a single unit of work within an EPN described by: type – kind of function performed, class – specific function, partition key – defines a unique instance, and agent-specification – defines the conditions surrounding the unit of work. The remainder of the presentation was focused around event context and associated patterns. Event context describes the following: semantic conditions that determine: which event processing agent should be activated, relevant time interval, spatial dimensions, and the entity responsible for determining the partition for the context. He wrapped up with a discussion of event pattern detection types: basic – single event; set – counts, statistics match a binary relation (gt, lt, eq, …); dimensional spatial/spatio temporal – instances within a certain distance and optionally in a certain direction; context termination – sequence or condition not matched with a context; and Interval oriented. Much of this work will be folded into material from the EPTS.
The last session of the day was led by Shailendra Mishra and Dieiter Galwick titled Technology and context. Much time was spent describing the new platform and positioning relative to other products. In general the Oracle platform is designed to handle incoming steams of data and create new streams called relationship streams. These two form the basis for everything else in the platform. Continuous queries are created to detect new relationships between stream events and possibly other existing relationship streams. CQL (continuous query language) is an extension of SQL that contains new predicates and operators for detecting and manipulating entity relationships. High availability architecture was discussed and a simple shared nothing approach was taken consisting of a master node and passive downstream nodes receiving and holding tuples. Checkpoints are then shared with downstream nodes once a tuple has been processed. Oracle indicated that they have found a much lighter HA set of requirements from customers regarding event processing vs. traditional databases. The session wrapped up with a discussion of managing sensor data and the need to archive and maintain the data for further inspection. Hmmm, I know a company that has a few products in that area. In general, the audience was not receptive to this discussion, but it is an important point that seems to always get overlooked in these discussions.
Off to day 2. Hope the air conditioning works in our new location - vintage 14th C building! I’m not expecting too much
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