Prototype tape library for advanced tape subsystems (MS8)

The Exploitability work package within ESiWACE contains the objective of: Developing New tape access strategies and software customised for Earth system data by first modelling and simulating possible strategies, and then developing a new software library which provides both higher bandwidth to tape storage and increased storage redundancy. We implemented and released a simulator for hierarchical storage as part of deliverable D4.1 “Business Model with Alternative Scenarios” https://zenodo.org/record/1228749#.W73BbfaYTwk (Chapter 6). The developed simulator was used to model a tape library with a cache system together with a simple network topology. The system allows to run traces recorded on existing tape archive and has been used to predict the DKRZ tape archive using real traces. Additionally, the deliverable provided a high‐level discussion of the models. We have since developed new software, consisting of a multi‐tiered storage library which provides a single API to users to move data to a number of different storage systems, query the data that they have stored on those systems, and retrieve the data. These interactions are carried out using a common user interface, which is a command line tool to be used interactively, and a HTTP API to be used programmatically. The command line tool essentially provides a wrapper for calls to the HTTP API. The source code for the multi‐tiered storage library can be downloaded from: https://github.com/cedadev/django‐jdma_control/releases/tag/0.1.6 This prototype meets the requirements for milestone MS8: Prototype Tape Library.ESiWACE has received funding from the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No 67519