On Thursday, 21 March 2019 15:27:35 GMT Itamar Turner-Trauring wrote:
Python and Twisted's built-in `logging` output a stream of factoids: they’re interesting, but you can’t really tell what’s going on.
* Why is your application slow? * What caused this code path to be chosen? * Why did this error happen? Standard logging can’t answer these questions.
But with a better model you could understand what and why things happened in your application. You could pinpoint performance bottlenecks, you could understand what happened when, who called what.
That is what Eliot does. `Eliot` is a Python logging system that outputs causal chains of *actions*: actions can spawn other actions, and eventually they either *succeed or fail*. The resulting logs tell you the story of what your software did: what happened, and what caused it.
Eliot has had good Twisted support from the start, but the latest release also supports inlineCallbacks, thanks to Jean-Paul Calderone.
You can learn more about Eliot at https://eliot.readthedocs.io/en/stable/
Interesting library. It seems that I cannot have a action finish with an error unless I raise an exception. That seems limiting, there are lots of cases where I have code that hits an error condition and does not raise an exception. For example an HTTP request that gets a non 200 status. Have I missed something? Barry