ACS service description draft ACS provides an Application

ACS service description draft • ACS provides an Application Archive Repository inside the system boundary. – Good place to keep packaged Apps ready for Deployment. – Defines standard format of the App Archive (AAF) and its Repository Interface (ARI). • An Application Archive (AA) contains a unit of the job in the grid system, which may be composed multiple application binaries. • ARI is designed to work with the sophisticated version control, data transfer, data replication services and so on, which are to be provided as higher level services. 1

What ACS defines • ACS specification 1. 0 defines two aspects: – AAF: defines the XML schema for Application Archive Descriptor (AAD), which defines an XML document syntax describing an each AA and acceptable physical representation for transport. – ARI: defines the resource properties and the operations supported by the implementation of the ACS repository in terms of the two port. Types. • AARepository represents an implementation of the ACS repository. • Application. Archive represents an each archive stored in the repository. • It works within the OGSA security model. 2

ACS, more in depth • Meta data in the ACS repository. – Producers of the Application Archive (AA) can embed meta information for application package, as a Application Contents or in the AAD. – ACS doesn’t specify the items or format of any data for Application Contents. Rather, they should be decided as a part of the system design for implementations. • What is not intended to be stored in ACS repository: – Job “instance” specific information – Information about the resources provided by the system 3

Does ACS define application model? • No. ACS only manages the descriptions of contents (such as filename, digest value and so on). Contents in AA is opaque to ACS and to be provided by producers of AA so that they satisfy the requirements of the target system. 4

What kind of meta information does ACS handle? • ACS specify the meta information required to manage the repository and AA such as list of contents, name and version of the archive, creation time, access constraint and so on. • ACS doesn’t specify the other meta information, but they can be stored and retrieved as an content in the AA. 5

Does ACS contain information for resource selection? • ACS specification does not enforce the restriction on the contents in AA. So it may be created to contain such information. • For example, if it is about the information related to the specific Job Managing entity in the system, it can be one of the application contents, which is opaque to the ACS repository. • However, we are conservative about including job “ instance ” specific information into AA. More appropriately, they should be stored in conjunction with the each instance of the job while AA is create once for a unit of the grid job, meaning one to many mapping. Job specific information should be kept separately from AA. Then the Job Managing entity should maintain the linkage information between the application specific information and job specific information. 6