Twitter is moving to its own data center, showing that sometimes the cloud is not ideal for the real-time web.

This may seem ironic as cloud computing is largely credited for giving application developers access to commoditized server networks that they can scale up or down. Cloud services make it realistic for developers to create real-time services in the marketplace.

But at some point, the cloud is not ideal for a real-time web service provider. Twitter is a good example. And, so, we use this news to present our weekly poll: “Is the Cloud Suitable For Scaling Real-Time Applications?”

According to Data Center Knowledge, Twitter now uses a managed hosting service from NTT America where it has a dedicated space. Twitter also uses Amazon Web Services to serve images, including profile pictures. Twitter parted ways with Joyent in January 2008.

The move NTT America came in response to latency issues. Latency is not a major issue for small application developers that use a service like Rackspace or Amazon. But when a service scales, the issues become increasingly significant.

John Adams of Twitter discussed scaling issues last week at Chirp, the Twitter developer conference.

Chirp 2010: Scaling Twitter

Latency issues pose a significant challenge to cloud computing services that serve real-time applications. It raises questions about how a service can scale in a cloud computing environment. In Twitter’s case, the cloud did not do the job.

Will the problem get worse?

Raghavan “Rags” Srinivas thinks it could:

“One of these fallacies is that “Latency is zero”. In traditional computing, the compute and data was typically hosted on the same system and the data latency was determined by the storage disks and the data bus speeds. It was a simple matter of buying better hardware to overcome data latency if it was ever an issue. In cloud computing and especially when we get to network of clouds with data expected to flow around different clouds, latency (however minimal it is) could be an issue depending on the data being manipulated, the network speeds and so on. Add to this the fact that the entire data or part of the data should be encrypted and decrypted when it moves around unreliable and public networks, and the fact that data needs to be streamed, latency will soon add up and could become a serious issue.”

What do you think? Will latency emerge as one of the major issues for cloud computing service providers?