Grid and Cloud Come Together at EGEE Event
Operating a grid site in the cloud: the beginning of a beautiful friendship?Source : - http://www.hpcwire.com/offthewire/Grid-and-Cloud-Come-Together-at-EGEE-Event.html?ref=472
March 30 -- The grid computing community may have found a valuable partner in a technology often presented as a competitor. Cloud computing, which has matured quickly over the last couple years, could be a useful platform for hosting grid services.
"The cloud's dynamic nature and heavy use of virtualization could ease resource centre management and simultaneously improve grid users' experiences," says Marc-Elian Bégin, partner of SixSq, an information technology company in Geneva.
Ideally, adopting cloud technologies to manage a resource centre would allow transparent treatment of hardware problems, automatic failover of services via machine migration, and in situ testing of upgraded services, easing the burden of site maintenance. Users benefit indirectly from less downtime, faster up-grades, and more reliable services.
However, the benefits to users are not all indirect. Cloud technologies allow users to define virtual machine images containing a complete software environment, working around the heterogeneous execution environments that are still a major source of job failures on the grid today. Additionally, users themselves can run services in the cloud, for example to coordinate large calculations, without having to contact a system administrator to allocate resources and to open firewalls.
Recent work weaving together the two types of computing was presented by the StratusLab collaboration at the 4th Enabling Grids for E-sciencE User Forum in Catania, Italy. This collaboration aims to run a complete EGEE resource centre in the Amazon cloud to determine how those resources can be federated with the grid and how robust those resources are.
To realize this potential, however, cloud resources must integrate with the grid's security and operational policies.
"The first steps towards running a grid site in the cloud turned up problems in surprising places, like difficulties when trying to obtain host certificates for the grid services," says Vangelis Floros, Grid & Cloud Computing Application Development at the Greek Research and Technology Network. "One of the first questions when trying to obtain a host certificate was 'Where are the machines located?' -- a very difficult question when using a cloud!"
The policies for obtaining certificates (and probably other policies) will have to be revisited with clouds in mind before widespread use of cloud resources. There were other minor technical issues as well. The unusual network configuration of the Amazon cloud and late availability of IP addresses required manual intervention and modification of service configurations to get services running.
StratusLab's short-term goal is to run a complete EGEE resource centre in the cloud for several months. Afterwards it will investigate bridging clouds, which at the moment operate as standing resources. A path to interoperability may be to connect an institute's resources, run as an "inner" cloud, with an "outer" cloud, like Amazon's commercial cloud, to expand an institute's resources when necessary.
StratusLab is an informal collaboration between CNRS/LAL, GRNET, SixSq Sàrl, and UCM. The collaboration is open to anyone who would like to participate. Although in its infancy, the collaboration posts results and current work on the collaboration's wiki: http://www.stratuslab.org/wiki/index.php/Main_Page.
