Paul Millar

Combining the X.509 and the SAML Federated Identity Management Systems

Every distributed computing infrastructure requires authentication and authorisation infrastructures (AAI) to manage access to resources and content. Several of such so called AAI systems are in use within different groups of users. In the Large Scale Data Management and Analysis project we aim to support and bring together many user communities. We therefore need to harmonise the currently used AAI systems. The approach described is to translate between different authentication systems. We furthermore try to maintain the same trust level wherever possible, and to harmonise authorisation across the involved systems.

Storage quality-of-service in cloud-based scientific environments: a standardization approach

When preparing the Data Management Plan for larger scientific endeavors, PIs have to balance between the most appropriate qualities of storage space along the line of the planned data life-cycle, its price and the available funding. Storage properties can be the media type, implicitly determining access latency and durability of stored data, the number and locality of replicas, as well as available access protocols or authentication mechanisms. Negotiations between the scientific community and the responsible infrastructures generally happen upfront, where the amount of storage space, media types, like: disk, tape and SSD and the foreseeable data life-cycles are negotiated. With the introduction of cloud management platforms, both in computing and storage, resources can be brokered to achieve the best price per unit of a given quality. However, in order to allow the platform orchestrator to programmatically negotiate the most appropriate resources, a standard vocabulary for different properties of resources and a commonly agreed protocol to communicate those, has to be available. In order to agree on a basic vocabulary for storage space properties, the storage infrastructure group in INDIGO-DataCloud together with INDIGO-associated and external scientific groups, created a working group under the umbrella of the Research Data Alliance (RDA). As communication protocol, to query and negotiate storage qualities, the Cloud Data Management Interface (CDMI) has been selected. Necessary extensions to CDMI are defined in regular meetings between INDIGO and the Storage Network Industry Association (SNIA). Furthermore, INDIGO is contributing to the SNIA CDMI reference implementation as the basis for interfacing the various storage systems in INDIGO to the agreed protocol and to provide an official Open-Source skeleton for systems not being maintained by INDIGO partners.

Transparent handling of small files with dCache to optimize tape access

We introduce a service for dCache that allows automatic and transparent packing and extracting of file sets into large container files. This is motivated by the adoption of dCache by new communities that often work with rather small data files which causes large time overheads on reads and writes by the underlying tape systems. Our service can be attached to existing dCache instances and we were show that it is able to optimize average access times to tape access.