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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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