OpenStack Swift as Multi-Region Eventual Consistency Storage for ownCloud Primary Storage

<!--HTML-->As more users adopt AARNet’s CloudStor Plus offering within Australia, interim solutions deployed to overcome failures of various distributed replicated storage technologies haven’t kept pace with the growth in data volume. AARNet’s original design goal of user proximal data storage, combined with national and even international data replication for redundancy reasons continues to be a key driver for design choices. AARNet’s national network is over 90ms from end to end, and accommodating this has been a key issue with numerous software solutions, hindering attempts to provide both original design goals in a reliable real-time manner. With the addition of features to the ownCloud software allowing primary data storage on OpenStack Swift, AARNet has chosen to deploy Swift in a nation spanning multi-region ring to take advantage of Swift’s eventual consistency capabilities and the local region quorum functionality for fast writes. The scaling capability of Swift resolves the twin problems of geographic redundancy, and user proximal access while scaling into the petabyte range. Significantly, the ring and policy capabilities allow overflow into short or medium term use secondary storage, such as the Australian RDSI project nodes, or Amazon S3. This helps deliver predictable near linear growth of capital and operational expenditures while allowing a higher rate of growth of data volume. Additionally, the policy capabilities within Swift combined with the ability to grant a user multiple storage targets within ownCloud, allow us to honour data sovereignty rules with respect to the physical location of the data on a per top level folder basis. Finally, using the combined read and write affinity features of the Swift proxy, AARNet is presently experimenting with deployment of flash cache backed site local application nodes, providing the perception to the user of near instant data ingestion, while the node trickle uploads data to the redundant bulk storage ring using private layer 3 networks. By switching to true object store systems, AARNet is able to achieve two of its original design goals for cloud storage services, chiefly being user proximal data storage, and continent-spanning geographic redundancy, from hundreds of terabytes into the petabyte scale.