April 2015 Summaries

Running computational fluid dynamics (CFD) problems on Rescale is akin to executing them on a local environment but with some additional considerations for efficiency and error management. Ensuring that the job runs successfully on a local setup before submitting to Rescale can prevent costly mistakes. The platform's Live Tailing feature allows users to monitor files in real-time, providing insights into errors or progress, while plotting residuals as image files can offer further analysis. Intervention during computation, such as adjusting parameters via SSH, can save runs from bad initial choices. Managing the large number of small result files effectively, by writing in binary or archiving them, can mitigate data transfer times. Rescale also offers remote desktop capabilities and the use of ParaView for viewing results without the need for downloading, enhancing convenience for users with limited bandwidth.

Rescale now offers users an easy way to view and export their detailed usage data. By accessing their account, users can see a summary of their recent usage and download monthly data in CSV format for further analysis in tools like Microsoft Excel. Additionally, users can check their received credits and view a usage chart. The post is authored by Adam McKenzie, Rescale's CTO, who oversees the HPC and customer success teams. McKenzie's background includes a significant tenure at Boeing, where he managed engineering projects on the 787, and he holds a Mechanical Engineering degree from Oregon State University.

Clayton Grow's article explores the concept of motion through the lens of philosophical paradoxes, humor, and scientific application. The discussion begins with a humorous line from Mel Brooks' film "Spaceballs," which is likened to Zeno's "Dichotomy paradox" and its reverse, highlighting the relationship between paradox and absurdity. The article progresses to Lewis Carroll's solution to the paradox, "solvitur ambulando," emphasizing practical experimentation as a means to resolve theoretical dilemmas. This concept is then applied to computational fluid dynamics (CFD), where the PISO algorithm and Adaptive Mesh Refinement (AMR) in Convergent Science's CONVERGE TM CFD solver illustrate prediction and adaptation in solving complex flow problems. The article underscores the role of high-performance computing in automating mesh refinement, presenting a future where cloud-based resources like CONVERGE in the Cloud TM on Rescale streamline the prediction and simulation processes, democratizing access to advanced CFD capabilities.

Rescale's exploration of Facebook's Immutable.js library highlights its potential to enhance JavaScript code by providing immutable data structures like Set, Map, List, and Stack, which are absent in ECMAScript 5. The adoption of Immutable.js at Rescale aimed to address challenges related to UI state management and improve code readability and performance. In a practical example, the library's OrderedSet is used to simplify a file selection model for a UI, reducing the complexity of code required for implementing a "Select All / Deselect All" feature. The transition to Immutable.js involves defining hashCode and equals methods for File objects to ensure unique identification, paralleling practices in Java. Despite potential concerns about performance overhead due to the creation of new data structures, the library offers advantages in terms of simpler $watch statements and more efficient DOM updates, particularly for applications with large data structures and numerous watchers. While not a universal solution, Immutable.js can be beneficial in improving both the readability and performance of JavaScript applications.