Invitation to be the Guest Editor for ACM Transactions on Storage (Special Cloud Storage Issue)
Folks, recently I have been invited to be the guest editor for the ACM journal of Transactions on Storage (special issue on Cloud Storage). The ACM transaction series of journals cover many key areas of computing science and are generally regarded as a premier set of technical journals. The purpose behind writing this blog is 1) to share my thinking about how to construct this special issue and get your feedback and 2) to encourage you all to submit paper ideas or paper abstracts. I also want to sincerely thank the editor-in-chief Sree for this opportunity.
Currently there is a lot of buzz going on about Cloud Computing. Many people are wondering as to whether there are any new technical problems in this area in comparison to grid/utility computing, or whether this is really a new business paradigm disruption and not a technical disruption. There are many different ways to classify clouds such as public or private, and infrastructure, application or storage clouds. Moreover, different providers are advocating different types of competing storage architectures for the clouds. The primary objectives of this special issue are: 1) to provide an introduction to the area of storage for clouds and how it relates to other types of clouds and the key motivation/use cases 2) to take the fluff out and highlight the key technical problems in this area from the standpoint of storage vendors, different types of cloud providers, and cloud users 3) to provide high quality technical papers that are addressing some of these technical challenges.
So, currently I am thinking about articles in the following key areas for this special issue (I would like your feedback):
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Intro to Storage Clouds: Motivates this area, provides classification, and then highlights the key technical challenges·
Security: These articles will deal with different types of threat models for the cloud. Deal with how to ensure that data that is not being accessed is still safe. Deal with provenance and meta-data management issues.·
QoS/SLA Management: Performance based SLA management is currently a major problem for the cloud providers. They are providing some initial forms of protection and availability guarantees. These articles deal with how to express SLA/SLOs, discuss different types of workloads, and describe underlying management mechanisms that help the providers to guarantee SLAs. QoS management is an extremely hard problem in light of multi-tenancy. Multi-tenancy is a key tenet to increase cloud resource utilization. SLA management also becomes a challenging problem especially when the scope of the cloud can span many data centers and geographies. Design of efficient fine-grained chargeback, and the design of penalty functions is also an interesting research area in this space.·
Protocols and Namespace: Currently Amazon S3 namespace, access model and protocol seem to be the dominant paradigm due to the first mover’s advantage. There definitely is a need to understand the interoperability between this access model and the traditional file system access models, also to understand the performance implications of this new http/object level access model.·
Storage Architectures: Currently, different providers and vendors are advocating different types of cloud storage architectures such as a large cluster of shared nothing nodes (with few disks behind each computing head) or large nodes with many disks behind each head. Some vendors are also advocating gateway nodes in front of traditional storage controllers to provide support for cloud protocols and policy based (SLA/SLO) management.·
Caching Technologies: Currently, many customers would like to store their archival copies in public clouds and have quick access to this copy from their private clouds. Similarly, another use case is where an organization has all of its data in the cloud and would like quick access to this data from geographically distributed locations (WAN distances). There are other use cases where a provider/.vendor would like to provide caching functionality for the storage it is current hosting.·
Standards: There definitely is a lot of opportunity and need to standardize cloud storage access models. Some might argue that it is too early to standardize because this will curtail innovation, I believe that many users are already moving quite fast towards adopting clouds. Thus, lack of standards will lock these users in, and will be a general liability towards further acceptance of clouds. Thus, there is a need for papers that describe various storage area cloud standards like SNIA CDMI, and how they are related to each other standards.·
Data Mobility: The amount of data being generated by most organizations is exponentially increasing. The problem of moving this data from the private cloud to the public cloud and vice-versa is a very important problem. Since WAN costs are still relatively expensive, there is a need for new types of compression/de-duplication techniques, and eager/lazy copy techniques to efficiently move data across WAN distances.·
Storage for Server Virtualized Environments: Many cloud providers are using some form of virtualization technology to increase server utilization. Please note that not all cloud providers are using standard off the shelf virtualization stacks but instead have some form of light-weight home grown stack to provide benefits similar to a hypervisor. There are numerous new challenges with respect to performance, management, protection etc when one accesses storage via a hypervisor due to differences in management granularity, due to loss of application context when going through a hypervisor, and due to overhead introduced by the hypervisor. Thus, there are a lot of opportunities for good technical papers in this area.In conclusion, I think some of the above problems have been looked at by people in general systems area. Thus, I encourage folks from the database area networking area, operating systems area, security area, fault-tolerance area, performance analysis area, and computer systems architecture area to also think about submitting papers to this special issue.