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Showing posts from January 31, 2010

The real concerns about Cloud infrastructure (as it is today)

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While “ private clouds may not be the future ” they are definitely needed today. Here are some of the top issues bothering some organizations which have been thinking about going into the cloud. Some of issues were based on Craig Bolding ’s talk on “Guide to cloud security”. Unlike your own data center, you will never know what the cloud vendors are running , or how they backup, or what their DR plans are. They will say you shouldn’t care, but do you remember what happened to the Tmobile customer’s on Danger ? Uptime, availability and responsiveness is less predictable than in a self hosted environment. In most cases the cloud vendors may not even choose to let customers know about major maintenance if they don’t anticipate any issues. Organizations who manage their own infrastructure would always try to avoid doing two major changes which have interdependencies. Multi-Tenancy means you may have to worry about a noisy neighbor . Muti-Tenancy could als

Fixing GSLB (Global Server load balancing)

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Standard DNS protocol allows DNS servers to respond with multiple addresses in the replies for simple DNS lookup queries. This, and the way that the order of records is changed in every reply is collectively known as the “ Round Robin DNS ” technique to load balance across a set of servers. Though a lot of organizations are using Round Robin DNS to load balance across servers in the same datacenter, some are also trying to use it as an HA solution by load balancing across multiple datacenters. In an event of a failure in one of the datacenter, using such an implementation, the impact could be limited, and with a slight change of DNS configuration (removing the IP of the datacenter which went down) the site could become fully operational again. It would be nicer if the DNS servers could monitor and remove servers which are inactive or are throwing  errors of some kind. This is what GSLBs are all about. But what they really excel at, which regular DNS servers can’t do, is that