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About
Our web applications, https://experiments.jcsda.org and https://skylab.jcsda.org run on two individual AWS EC2 instances in us-east-1. They are Voila applications running on port with the 8866 on an nginx web server on ports 80/443. The web apps are simply python notebooks in the diag-plots repository with r2d2 and solo as the only dependencies. These packages are located in /home/ubuntu. The Viola middleware service strips the cells from each notebook at runtime and displays only the user interface graphics . Each web app is executed from their own instance. The logs on these instances required for the drop down menus and image viewing. Every time someone visits one of these web pages, a new Python3 kernel is started in memory. Over time, this leads to OutOfMemoryErrors from the OS and the web apps freeze up and the instance will have to be rebooted as detailed below.
The error logs are located at /var/log/nginx/error.log and can be access accessed by executing
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journalctl -u voila.service |
The r2d2, solo, and diag-plots repositories are needed and are located inside the home directoryhttps nginx configurations are at /etc/nginx/sites-enabled/experiments.jcsda.org and /etc/nginx/sites-enabled/skylab.jcsda.org. Do not change these unless you know what you are doing.
Procedures
Reboot EC2 Instance
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