Bridging WSRF services and the EGEE middleware Process Management Pedro Andrade CERN, Geneva (on behalf of the University of Basel team)

Outline Process Design and Verification Process Execution and Reliability Process Optimisation GT4 gLite 09/11/2018

Process Design and Verification GUI for specification of processes: Loading/editing/storing of process specifications Specify transactional behavior Browse the DIS for the activities (services) composing the process Processes verification: Syntax and semantics check Execution only accepts approved specifications Specify transactional behavior... e.g. alternative execution paths ========== A process is composed of activities 09/11/2018

Process Execution and Reliability Responsible for the compond service execution Dynamically select “best nodes“ for the execution of process activities Using Process Optimisation Control of the execution is moved to the target node of the current activity Failure-handling If transactional guarantees provided, rollback or execute alternative paths 09/11/2018

Process Optimisation Optimisation: Pre-planning (before execution): Re-ordering of activities Parallelising as much as possible Pre-planning (before execution): For processes with short expected runtime Using the global knowledge of the process specification Annotate each activity with the “preferred“ nodes for execution Matchmaking (at runtime): For process with long expected runtime Using local knowledge only (self + successors) Look for the best nodes for the successor activites 09/11/2018

GT4 The following WSRF and WSN specifications are used: WS-ResourceProperties WS-ResourceLifetime WS-Base-Notification WS-BaseNotification WS-Topics 09/11/2018

GT4 Only the Process Execution and Reliability service is WSRF and WSN compliant Each running instance of a process is represented by a UUID Each node taking part in the execution of that process instance creates a WS-Resource with that UUID The process execution coordination requires this service to implement brokered notification through the DIS A Universally Unique Identifier is an identifier standard used in software construction, standardized by the Open Software Foundation (OSF) as part of the Distributed Computing Environment (DCE). The intent of UUIDs is to enable distributed systems to uniquely identify information without significant central coordination. Thus, anyone can create a UUID and use it to identify something with reasonable confidence that the identifier will never be unintentionally used by anyone for anything else. Information labelled with UUIDs can therefore be later combined into a single database without need to resolve name conflicts. The most widespread use of this standard is in Microsoft's Globally Unique Identifiers (GUIDs) which implement this standard. A UUID is essentially a 16-byte number and in its canonical form a UUID may look like this: 550E8400-E29B-11D4-A716-446655440000 09/11/2018

gLite gLite Wrapper: WSRF service which integrates gLite jobs into processes Each job is represented by a WS-Resource. The ResourceProperties contain information about: JDL (passed as input parameter to the service) Job ID Status number Status message (can be updated during job execution) Job output (?) WS-Notification is triggered by status changes: If clients are subscribed The client is asynchronously notified 09/11/2018

Questions ?? Thank you !!! http://www.diligentproject.org pedro.andrade@cern.ch 09/11/2018