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Usage Statistics Collection by Swift

Swift sends usage statistics back to the Swift development team to measure worldwide usage and and improve reliability and usability.

Why are we doing this?

The Swift development team receives support from government funding agencies. In a time of funding scarcity, these agencies must be able to demonstrate that the scientific community is benefiting from their investment. To this end, we want to provide generic usage data about such things as the following:

To this end, we have added support to Swift that will allow installations to send us generic usage statistics. By participating in this project, you help our funders to justify continuing their support for the software on which you rely. The data sent is as generic as possible (see What is Sent? below).


We are using opt-out rather than opt-in. The reason is that we need this data - it is a requirement for funding. We're sure our fellow users would be willing to help show that Swift works and is in use. Realistically, however, we know that if it requires any additional effort to set up usage statistic reporting, it would drastically reduce the number of users that would actually report the data. To be effective, we need to require zero additional effort.

By not opting out, and allowing these statistics to be reported back, you are explicitly supporting the further development of Swift.

If you must opt out of usage reporting, set "SWIFT_USAGE_STATS=0" in your environment.

What is sent?

How is the data sent?

The data is sent via UDP. While this may cause us to lose some data, it drastically reduces the possibility that the usage statistics reporting can adversely affect the operation of the software.

When is the data sent?

Once when Swift starts a script, and once when the script is completed.

What will the data be used for?

The data will be used for answering questions such as:

We will also try and mine the data to answer operational questions such as:


Please send us your feedback at swift-devel@ci.uchicago.edu. Feedback from our user communities will be useful in determining our path forward with this in the future. We do ask that if you have concerns or objections, please be specific in your feedback. For example: "Our site has a policy against sending such data" is good information for us to know in the future. A link to such a policy would be even better.