OPM Events in Plier

It is highly required within the e-BioInfra to capture the occurrence of events during the execution of a workflow experiment (e.g. timestamp when a process is queued, running, and completed or failed).
In this section, we present some hints related to events in OPM and how they are handled within eBioCrawler.

1. Events in OPM:
   Events in OPM are expressed using OTime concept, which is linked to Causal dependencies ('Used', 'GeneratedBy', 'ControlledBy', 'TrigredBy', 'DerivedFrom')
   • Artifact USED by Process at OTime,
   • Artifact GENERATED by Process at OTime,
   • Process CONTROLLED by Agent at OTime,
   • Process TRIGGERED by Process at OTime,
   • Artifact USED by Process at OTime,
   • Artifact DERIVED from Artifact at OTime.
   The event occurs:
   1. noEarlierThan: (no earlier than this time),
   2. noLAterThan: (no later than this time),
   3. exactlyAt: (exactly at is disjoint from noEarlierThan and noLAterThan).

   The way of describing events in OPM is very general and can only describe occurence time.

   1. It is not capable of representing execution information,
   2. It is not capable of representing high level process details,

2. Handeling Events within eBioCrawler:
   To cope with events, eBioCrawler deploys the Annotation/Propriety OPM concepts to represent the occurrence of events during the different processing stages. The eBioCrawler builds events as follows (for each process):
   1. Create an Annotation with 'STATUS' as value for 'LocalSubject' ,
   2. Create a set of Properties (e.g. QUEUEUD, RUNNING, ERROR, and COMPLETED) with Time as value for each property (time as long/string)
   3. link the set of proprieties to the annotation, and
   4. link the annotation to the process

   For more details, please check the step-by-step example OpmDBTest and the complete java source code example OpmDBTestSample examples given on Plier wiki page.

   
   -- AmmarBenabdelkader - 21 Jan 2011
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