Why Clusters in the Cloud Doesn’t Make Sense

Clustering has been an important tool in the IT architect’s tool belt for many years now. Put a group of servers or storage together on a LAN, add some well-planned redundancy, and top it off with a cluster controller, and you’ve increased your fault tolerance enormously. Clustering is at the heart of RAID technology, application server clusters, and database clusters — all examples of what we call high-availability clusters.

Take the notion of clustering one step further and you can build single system images. The idea of a single system image is to group physical servers into a high-availability cluster and abstract them so that the cluster appears to be a single server. Single system images are good for certain high-performance computing tasks, and also underlie Storage Area Networks (SANs).

Clustering technology, including high-performance single system images, solve a wide range of problems, but they have little if anything to do with Cloud Computing. In fact, the Cloud takes a diametrically opposite approach, because Cloud environments are inherently partition tolerant, while clusters are partition intolerant.

Partition tolerance means that communication between nodes can drop and the overall application keeps working, which is certainly not the case with clusters. Clustering depends upon continuous communication among nodes in the cluster, which is why you put them on high-speed LANs. However, not all high-performance computing tasks require continuous communication among nodes — or even any communication at all in some cases. This fact gave rise to an alternative to clustering called grid computing, a way of building massively parallel, partition-tolerant collections of servers. The 1990s SETI at Home alien-searching screen saver was perhaps the most familiar example of grid computing.

What grid computing lacks, however, is virtualization. With virtualization, we create a number of virtual servers (virtual machines, or VMs) on each physical server — the opposite of single system images, which group physical servers into a virtual server. Add virtualization to grid computing, and you end up with an elastic collection of partition-tolerant VMs. Now we’re talking Cloud.

As a result, applications that require clustering to work properly, like enterprise RDBMSs, are inherently Cloud-unfriendly. Don’t let the vendors fool you. If they’re talking about clusters in the Cloud, either they don’t know what the Cloud is, or they’re simply pulling the wool over your eyes.

You’ve been warned!

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

technology leadership

Why the World Needs More Technology Leadership

As a fact, technology has touched every single aspect of our lives. And there are some technology giants in today’s world which have been frequently opined to have a strong influence on recent overall technological influence. Moreover, those tech giants have popular technology leaders leading the companies toward achieving greatness.

iOS app development

The Future of iOS App Development: Trends to Watch

When it launched in 2008, the Apple App Store only had 500 apps available. By the first quarter of 2022, the store had about 2.18 million iOS-exclusive apps. Average monthly app releases for the platform reached 34,000 in the first half of 2022, indicating rapid growth in iOS app development.

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job