Growing Pains of Cloud Storage

Cloud storage is growing at a phenomenal rate and is fueled by multiple forces: Mobile Devices, Social Networks, and Big Data. Content is created any time and any where on billions of smartphones and tablets; high resolution photos and videos are frequently uploaded to the cloud automatically as soon as they are captured. A Gartner Report predicts that consumer digital storage would grow to 4.11 zettabytes in 2016, with 36% of it in the cloud[4]. All the social interactions and transactions on the Internet are frequently captured for targeted advertising. Besides Social Networks and E-commerce, Big Data analytics are growing in many other sectors as well, including government, health care, media, and education. An IDC forecast suggests that the storage of Big Data is growing at a compound annual growth rate (CAGR) of 53% from 2011-2016 [1]. The growth of cloud storage has made it an expensive cost component in many cloud services and the cloud infrastructure today. While raw storage is cheap, the performance, availability, and data durability requirements of cloud storage frequently dictate sophisticated, multi-tier, geo-distributed storage solutions. Amazon S3 offers 11 nine’s of data durability (99.999999999%), but some other cloud storage services demand even more stringent requirements due to the sheer number of objects being stored in the cloud these days (1.3 billion Facebook users, uploading 350 million photos each day) and the importance of the data (who can afford to lose a video of your baby’s first steps?). Data is frequently replicated or mirrored in multiple data centers to avoid catastrophic data loss, but copying data across data centers is very expensive. The networking cost is frequently proportional to the distance and bandwidth requirements between the datacenter sites. Traditional storage systems use dedicated storage hardware and networking to guarantee that the storage QoS requirements such as throughput, latency, and IOPS (total number of input/output operations per second) are preserved. Unfortunately, these dedicated resources are frequently underutilized. Cloud computing promises efficient resource utilization by allowing multiple tenants to share the underlying networking, computing, and storage infrastructure, but it is difficult to provide end-to-end storage QoS guarantees to individual tenants without mechanisms to avoid interference. Typically, in a cloud