Jessica Souza

During my internship, I worked with the Unidata THREDDS team. My intentions this summer were to learn Java, improve my coding skills, and have experience using it in real world applications. I began my journey by converting existing unit tests for the netCDF-Java library, which is tightly linked to the THREDDS Data Server (TDS) code, to the JUnit Java testing framework. Once I got this practice with Java and had a working development environment, I was able to start working on my summer project.

Unidata is looking for community contributions to the Jupyter Notebook service, which provides Jupyter Notebooks to facilitate accessing, exploring, and visualizing datasets in the TDS. Users who have written Notebooks that interface with TDS datasets (or Python scripts that can be converted) or are interested in creating one can contribute in one of two ways (or both!):

1. Contribute a generic viewer that would be a useful in a typical THREDDS Data server (see the GitHub issue here).
2. Contribute a viewer for a specific dataset, data type, or catalog included in the Unidata THREDDS Data Server (see GitHub issue here).

The issues above are eligible for Hacktoberfest: you get Hacktoberfest credit and help the Unidata community! For more information on contributing and some helpful links, visit the GitHub issues above.

Happy hacking!

Hailey Johnson

by Hailey Johnson
2018 Unidata summer intern

During my time here at Unidata, I’ve focused on extending the THREDDS Data Server (TDS) web interface and services. I spend the first few weeks of the summer redesigning the interface to be more intuitive to end users and implementing UI changes using Thymeleaf HTML templating. The new TDS catalog pages are designed with a “plug-and-play” structure, allowing users to override or insert their own contributed HTML, which is processed by a server-side Thymeleaf template resolver.

As we approach the first public beta of version 5.0 of the THREDDS Data Server (TDS), we have decided to revisit our software license. Currently, both NetCDF-Java and the TDS are released under the same license that the netCDF C library uses, which is a license that was "home grown" at UCAR. It's usually called an "MIT-style license," though it is perhaps more similar to the BSD-3 Clause license. Rather than continue to use the "home grown" license, we will be moving to a standard, off-the-shelf BSD-3 license, bringing the TDS and NetCDF-Java packages more in line with standard practice within the Open Source community.

Periodically some of the Thredds servers run by Unidata get seriously overloaded. One cause is because external users poll the Thredds server to see what has changed. If the polling rate is too high then the performance of the Thredds server can seriously deteriorate.

I am proposing here to mitigate this problem by allowing Thredds servers to generate events that signal changes that might be of interest to users. Then, instead of polling, these users can watch for specific changes events and use that information to update their local databases (or whatever).