Scheduler Interactions

Synopsis

Within scope

• Simple request for a computing resource
• Basic set of service-level objectives (SLOs) passed from one scheduler to another (mainly time-related)
• Definition of interfaces
• Defintion of messages

Out of scope (during the first period)

• Other resource types (e.g. integration of data resources)
• Complex service-level objectives
• Definition of a unified information model (in general it is assumed that the different local Grid Information Systems have different information models)

Architecture

Main entities

• Client
• Scheduler
• Adapter

Utility entities

• Registry
• Local GIS (Grid Information Service)

Approach

Assumptions

• A scheduler does not know anything about other schedulers. All information needed has to be passed via the one scheduler interoperation interface.
• There is no common information model (apart form CIM, but this is not meant here).

JSDL "profile"

Scheduling attributes

• Hard deadline for the end time of job execution
• Earliest start time
• Duration
• Service-level objectives/scheduling preferences/scheduling objectives: xsd:string or xsd:any.

Additional attributes for inter-scheduler communication

Negotiation protocol

Actions

• (Ariel) Starting point for the JSDL profile and the scheduling attributes. The goal is to agree on a basic set to be put into an SLA.
• (Oliver) Write a document on the negotiation protocol.

Issues

Open

• issue_001 Definition of a real use-case: which schedulers (VIOLA, GRMS, others?), first ideas concerning scenario, what should be the exact outcome we want to demonstrate?
• issue_002 Design of scheduler interactions (sequence diagrams?): probably we can distinguish several scenarios depending on assumed environment, type of Grid etc.?
• issue_003 Between which entities should agreements be establish?
• issue_004 What are the parameters needed for scheduling? Parameter semantics/syntax?
• issue_005 How to handle different models of constraints/preferences?
• issue_006 Job execution: Who is executing a job and who is controlling/managing/monitoring it?
• issue_007 Does the primary scheduler/broker transfers the responsibility for the whole job to the secondary one or is a splitting possible?
• issue_008 Negotiation protocol.

Closed

• During the 2006/10/04 telecon it has been decided that it would be a good idea to use the generic communication stages (see slide 2 of this PPT) and start with sequence diagrams for the different sub-steps needed to perform scheduling.
• The decision whether or not a scheduler passes a request to another scheduler in case it cannot fulfil it is internally taken and not of concern wrt to the scenario (2006/10/23).
• Data management very much of interest, but will not be tackled in the first period (2006/10/23).

Attachments:

inter_scheduler_services.jpg [SchedulerInteractions/inter_scheduler_services.jpg]