Documentation/Labs/ApplicationUsageAnalytics

Requirements

• We would need to know:
  • Slicer application downloads
  • extension downloads
  • Slicer application startups
  • Slicer module usage (how many times user switched to a module and % of time used)
• Possibility of hosting our own server would be preferred (to avoid blocked in certain countries, ensuring long-term access to our data, etc.)
• User should be notified and have the option to opt out
• It should not be tightly integrated into Slicer (should be an optional module that can be excluded from the build)
• It should be possible to customize it for private builds of Slicer (so that it can use a different backend)

Design

• Slicer-side:
  • add a few Qt events that a Python module can observe (application startup, module switch, crash, etc)
  • data caching (so that data can be uploaded later, when there is network connection)
  • data accumulation (report metrics such as total hours of Slicer and individual modules used instead of reporting each module switch)
  • data uploading: this is the only server-specific component
  • Probably it would be a Python module, as Python SDK is available for almost all services
  • must be non-blocking
• Server: there are many options, none of them are perfect, see below

Server options

• Hosted services: easier to get started, no need for experts to maintain/update; may be locked out from certain countries, limited customization
  • Google Universal Analytics: The largest and most sophisticated solution for traffic analysis that you can get for free. APIs are provided for desktop app tracking, but built-in features are mostly geared towards website and e-commerce tracking - and not optimal for desktop applications (where you would want to send aggregate metrics, accumulate and upload data in batches, etc. - see comparison to Revenera for a list of limitations).
  • Many other similar services, for a small monthly fee (typically below $100), see https://github.com/onurakpolat/awesome-analytics
  • Revenera: Specialized desktop app usage tracker. It is supported on win/mac/linux, could do everything what we need very nicely, but it's not open (you have to link a binary library into your application).
• Self-hosted open-source systems: free, we can control our destiny, chance of being locked out from countries can be minimized; significant amount of work to set up and maintain
  • https://piwik.org/
  • http://www.openwebanalytics.com/