The reliability and low cost of cloud computing is no longer in doubt. When you have providers such as Amazon, Google, and Microsoft offering 99.99 percent uptime and some of the biggest companies in the world using their services, questions of robustness and dependability can be easily answered. Cloud services also offer the bonus of only paying for what you use, easy and low-cost scalability, improved collaboration possibilities, and huge savings on IT support costs.
But concerns about the cloud do still exist for many manufacturers, especially around security and availability. When using public cloud services, all information sent through those networks can be a target for hackers simply because it is on such a network. In addition, the government can access your information on a public cloud without a search warrant, and there can be concerns with bandwidth overload or problems accessing your applications when you have no Internet access. Beyond these issues, there are also concerns about latency and connection failures compared to a direct network connection.
At Inductive Automation’s first user conference, Travis Cox, director of training at Inductive Automation, hosted a session explaining the benefits and concerns surrounding cloud services use by manufacturers. Referencing HMI/SCADA software applications like Inductive Automation’s Ignition, Cox said the best use of the cloud is for data collection and analysis, such as historical data, graphs and tables, reporting, and alarm history.
Cox cautions, however, that it is “not the best idea to use the cloud for real time status and control applications.” Examples of such applications could include any “non-encrypted connections to PLCs or when writing values to a PLC.”
Since cloud hosting can clearly be of benefit to many manufacturing applications, Cox devoted a portion of his presentation to explaining the similarities and differences between two of the top cloud services available for manufacturers—Amazon Web Services and Windows Azure.
Amazon Web Services offers three categories of service:
• EC2 (Elastic Compute Cloud) for scalable, pay-as-you-go compute capacity. Inductive Automation hosts its web site here;
• S3 (Simple Storage Service), which is essentially a cloud file server, Cox said. Inductive Automation stores files here, and it can be designed so that the files hosted on this site appear to be on your site when accessed by a user through your site.
• RDS (Relational Database Service) is a newer service, Cox said, for managing MySQL, Oracle and SQL Server databases. “This service is good for databases used for analysis,” he said. “Amazon handles deployment of all patches to databases on this service and handles backup too, which is critical for large databases.”
Like Amazon Web Services, Windows Azure from Microsoft offers three similar categories of cloud computing services:
• Virtual Machines for hosting Windows or Linux applications;
• Storage and Backup; and
• Managed SQL Server Databases
“A lot of manufacturers gravitate toward Azure because they've standardized on SQL Server,” said Cox.
Like the services offerings from Amazon and Microsoft, the cost and computing structure for cloud services from each is very similar as well.
For example, comparing the virtual machine cost comparison between Amazon and Microsoft, Cox noted that:
• Amazon offers an m1.Large Windows OS dual core machine, 7.5 GB of memory and 10 GB of transfer for about $277 a month. Cox notes that the Linux offering of this service is cheaper.
• Windows Azure offers a Large Windows OS quad core machine with 7 GB of memory and 10 GB of transfer for about $268 a month “Many manufacturers go here because of their comfort with Windows,” said Cox.
Comparing the cloud-based database services from Amazon and Microsoft, Cox said that Amazon’s MySQL service with 50 GB storage and 10 GB transfer costs about $515 a month. Windows Azure’s SQL Server for 50 GB storage and 10 GB transfer costs about $500 a month.
Cox also made note of private cloud services such as Eucalyptus, for those who like the idea of cloud services but have specific privacy and security concerns. Eucalyptus is an open source Amazon Web Services offering.
With Eucalyptus, you can “take advantage of all Amazon Web Service offerings but in a private cloud for development and testing,” Cox said. “Because Eucalyptus is a private network there are less latency and bandwidth issues as one could encounter with public Amazon Web Services and Azure, but you have to commission the machines on this service yourself.
