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Cloud storage issues are more complicated than you think

Your app might be happy in the cloud, but it's possible your storage might not be. Find out why 'noisy neighbors' can make cloud storage so tricky and what to do about it.

One of the myths surrounding the cloud is that once applications are created or ported to them, storage isn't an issue. With vendors selling multi-tenant services that promise scalability and flexibility, it's easy for organizations to be lulled into thinking there won't be any cloud storage issues -- but that can't be further from the truth. As experts have noted, there is a definite gap between cloud applications and cloud storage, and ignoring this fact could result in performance problems.

The noisy neighbor dilemma is one that dogs cloud applications. With virtualization meaning 10 different applications may run on the same server, they're all competing for the same storage resource, according to Dan Florea, director of product management at Tintri, a storage provider specializing in the cloud. For example, a database with a very I/O-intensive workflow may need more resources to read data from storage. At the same time, a virtual desktop may be trying to access that same storage, and without some sort of regulation mechanism to ensure fairness, one user may be waiting for an unacceptable amount of time for the data.

Load balancing can alleviate latency woes

Load balancing can help distribute application resource use across servers, according to Michael Pardue, senior architect at Accusoft, which makes imaging processing tools. "One of the first things we try to do is break away from the local file system to various cloud service providers like AWS [Amazon Web Services]," he said. Otherwise, there needs to be more load balancing on the client side so that when the request comes through the server, all the resources are still available.

"We want to have a number of servers online to handle a large number of requests," Pardue said. That means maintaining the notion of the session and coordinating requests across servers. Accusoft engages in "round robining," sending requests to indiscriminate servers, he said.

Keeping application data out of the blender

Another cloud storage issue is mixing data from applications, Florea said. If data from two or more applications is all stored in one partition, it's possible for the information about the applications to be mixed up and not useful for the business.

However, with VM-Aware Storage (VAS), the application looks directly at the virtual machine and accesses the analytics for each particular application or virtual machine, Florea said. Another advantage to VAS is that all operations like snapshots, clones, replication and syncing happen at the virtual machine level and are then transferred to storage, whereas with traditional storage, snapshots include data from all the other virtual machines, as well.

Pure cloud isn't always the issue

A lot of organizations aren't using pure cloud solutions, which can cause storage issues that impact applications, according to Ross Turk, director of product marketing at Red Hat Storage. Most are using a combination of on-premises storage and cloud storage, and the challenge lies in constantly moving data back and forth. Each type of storage can handle the data differently, given the different object storage APIs and cloud file storage characteristics, leading to a mismatch, he said.

Embracing more modern storage techniques, like software-defined storage, can help bridge the on-premises and cloud storage problems that plague applications, Turk said. These technologies help synchronize between the two and are more flexible for multiregional operations and hybrid cloud configurations.

Examine object storage when creating new applications

For developers, cloud storage issues can be overcome by looking at object storage when building new applications for the cloud, as it is more portable and more abstracted, Turk said. For example, if the developer is building an application that consumes the Amazon A3 API, the developer can't use another cloud service API. But object storage APIs offer more portability and more potential to scale out the architecture, he said.

Object storage is also more cost-effective in the cloud. "The object storage services out there tend to be priced cheaper than equivalent file storage services," Turk said. Using object storage also makes it easier to span the hybrid cloud.

Educate the storage administrators

Meanwhile, to work past cloud storage issues, companies can start with education, according to Turk. A lot of organizations, as a whole, delegate their storage decisions to storage administrator groups used to managing appliances, not cloud resources. These groups might not have the same amount of ease when working with cloud-based storage challenges, so educating the storage administrators on hybrid cloud storage, and cloud storage in general, and replicating from on-premises storage to a cloud service can go a long way. It also means storage administrators, over time, will begin to develop more DevOps skills, he added.

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What's the biggest challenge you've faced while dealing with cloud storage?
Our biggest challenges were getting data into the cloud in a timely yet cost effective manner, and determining which data to put into which storage tier.
Whilst I agree that moving storage to the cloud isn't easy, this article misses the point of cloud. The issues described here are all issues that you will have in your own poorly designed infrastructure and this article assumes that you just "lift and shift" your workloads to something like AWS. In reality you would re-engineer your workloads to take advantage of cloud features. Until you are ready to do that perhaps you are not ready to make the move.
I don't think that technological problems, like load balancing, described in the article, should concern cloud storage customers. They pay for convenience, and if the quality of storage is below expectations they will just go to a competitor.
This is a great issue to explore. It might have been a better article with a user in an organization that is experiencing noisy neighbors. I have often asked cloud users if they problems with multi-tenant, but all deny it. At least one did not even know he was on multi-tenant. At the same time, some organizations will pay up big for single-tenant, or their own server.  
It could be interesting to know if noising neighbours only are a Windows Server problem or similar problems exist on larger servers like IBM z Systems. My guess is that the problem is that Windows servers not really are built for neither multitenancy nor real load balancing and the problems multiplicate when you need to cluster Windows servers.
I have to agree with @carlosx15 - the problem isn’t the technology, it’s improper use of the technology. AWS Elastic Block Storage offers three volume types, two of which are SSD - General Purpose, which offers a ratio of 3 IOPS per GB up to 10,000 IOPS, and provisioned IOPS, which offers more than 10,000 IOPS. If you’re not getting the performance you need, you need to look at whether you’re using the correct offering your cloud vendor provides. That would be cheaper than launching an instance of an elastic load balancer.
Very good point @mcorum. "User error" is a real possibility.