Brief Overview of Major Enhancements to PAWN
Producer – Archive Workflow Network (PAWN) Distributed and secure ingestion of digital objects into the archive. Use of web/grid technologies – platform independent Ease of integration with data grids or digital libraries. XML Representation of metadata and bitstream Self describing bitstream submissions Accountability of transfer and guarantee of data integrity
Ingestion Workflow (PAWN) 1. Negotiate Submission Agreement. 2. Workflow Initialization and Submission Information Packet (SIP) creation. 3. Transfer of SIPs to receiving servers. 4. Validation of SIP transfer 5. Organization of data into collections and transfer into the distributed archive.
Distributed Ingestion
Each Producer registers and arranges files locally prior to transport. Multiple distributed archival receiving stations. X.509 based authentication between sites. Independent Certificate Authorities at each Producer. Persistent archive is geographically distributed and managed by a data grid.
Producer Provides data to an Archive based on a prior agreement. Consists of a management/metadata server and an ingestion client. Provides initial arrangement, context, and metadata.
Enhancements to the Producer Data submissions are organized through a logical hierarchy negotiated between the archive and the producer. Clients no longer see entire hierarchy, but rather attachments points Better state tracking and oversight of submissions METS documents are no longer merged together, but rather kept separate to support larger submissions. Submission can be broken into multiple METS documents linked together through pointers. Producer signed submissions to ensure integrity.
Different administrator and client views Manager / Record Manager Administrator Views entire producer hiearchy Producer / Record Creator View restricted to allowable submission points
New Interactions Between Client and Receiving Servers Ability of client to reserve resources before starting to transfer data into the archive. Client creates a session with a receiving server and uploads metadata. Clients upload bitstreams, and receiving server validates checksums during transfer Client can resume or retransmit failed submissions
Client-Receiver Interaction
Archive - receiving Receives data from a Producer Validates bitstreams and metadata, and sends acknowledgement to Producer. Arranges into collections and specifies preservation policy. Publishes bitstreams into a digital archive.
New Features for Receiver Validation Services Designed a standard API and test suite for rapid development of validation services. New classes of services can be easily developed. Receiving Server Configurable endpoints into storage or metadata repositories Better handling of multiple producers
Scheduler Allocates the processing of data streams from multiple clients to a cluster of receiving servers. Clients are required to request a resource reservation. Receiving server will acknowledge/deny the reservation. Client will be informed about reservation/receiving server. Currently, receiving server has hooks for scheduler