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Submission + - Ask Slashdot: How reproducible is arithmetic in the cloud? 1

goodminton writes: I'm research the long-term consistency and reproducibility of math results in the cloud and have questions about floating point calculations. For example, say I create a virtual OS instance on a cloud provider (doesn't matter which one) and install Mathematica to run a precise calculation. Mathematica generates the result based on the combination of software version, operating system, hypervisor, firmware and hardware that are running at that time. In the cloud, hardware, firmware and hypervisors are invisible to the users but could still impact the implementation/operation of floating point math. Say I archive the virutal instance and in 5 or 10 years I fire it up on another cloud provider and run the same calculation. What's the likelihood that the results would be the same? What can be done to adjust for this? Currently, I know people who "archive" hardware just for the purpose of ensuring reproducibility and I'm wondering how this tranlates to the world of cloud and virtualization across multiple hardware types.

Comment several options 4 u (Score 2, Insightful) 308

I agree with the previous commenters that it's important to have a solution or plan before raising the alarm. Having said that, once you raise the alarm and you're not being heard to your satisfication, there are several options available: * First, clear your mind of what you think you know about software development and what SHOULD be and try to see the situation from an open-minded perspective. Are the issues you're seeing really an indicator of poor quality or are they an indicator of a system that's different from what you know/like? As a quality/regulatory person myself, I've seen many unnecessary projects and alarm bells simply because of a lack of understanding/perspective on a given topic. I'm not saying that's the case with you, just that this is the kind of issue that's good to be absolutely clear with yourself about. * Once you're clear that there is in fact an issue, go to QA and request an internal audit on your software development/quality systems. If your QA team doesn't have a procedure by which you can request an audit, then you should find a QA partner who can work with you on this. It's good to have a QA partner anyway so building the bridge on this project won't be a waste of time regardless of the outcome. * If auditing isn't an option, or if you need ammo to sell the audit idea, another approach is to analyze deviation and/or CAPA trends on your software development process, as well as your validation process. For example, try to find out how many validation deviations are being generated when new/updated software is released from your development team. Working with QA, you could develop an estimated cost-per-deviation, which would be a huge pile of ammo for your management presentation. Also, pretty charts and graphs will help too. * Find other tangible evidence of the issue. Without specific examples it will be difficult to be clear about the problem and/or the solution(s). * If you find evidence and QA and/or management still won't listen, it's time to consider your options. You can either stay, knowing that a ticking time-bomb exists, or you should carefully plan and execute your exit from the company. My litmus test for working at a company is to regularly ask myself whether I'd give my company's medicine to a family-member [a family member I love :P ]. If the answer is no, I don't stick around. So far, I've only had to do that once in 10 years and it was absolutely the right choice. Good luck!

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