A lightweight, optimized, and opinionated structured logging library for Python, intended for containerized applications.
containerlog was born out of a desire to have high-quality structured logging for
containerized applications (e.g. microservices) without having to compromise detailed
logging for application/request latency.
structlog is a great general-purpose structured
logging library for Python, but being general-purpose means that there is additional overhead
when logging messages.
When we updated a microservice to use structured logging,
we found that request latency went up,
seemingly due to the transition to use structlog.
containerlog is not for everyone. It is highly opinionated, minimally configurable,
and intentionally feature-sparse so that it can achieve better performance than
the Python standard logger
Not every application needs optimized logging, but where latency and performance matters,
containerlog could work for you.
timestamp='2020-07-23T13:11:28.009804Z' logger='my-logger' level='debug' event='loading configuration' path='./config.yaml'
timestamp='2020-07-23T13:11:28.010137Z' logger='my-logger' level='info' event='starting application'
timestamp='2020-07-23T13:11:28.010158Z' logger='my-logger' level='warn' event='having too much fun' countdown=[3, 2, 1]
containerlog can be installed with pip:
pip install containerlog
It is only intended to work for Python 3.6+.
See the documentation at https://containerlog.readthedocs.io/en/latest/
There are numerous sources discussion micro-optimizations in Python. This project probably does not implement them all, so there is room for improvement. Current optimization work has leveraged:
If you wish to contribute optimizations and use other libraries, tools, or sources, open a PR to add them to this list.
Benchmarking scripts can be found in the benchmarks directory. To run,
$ cd benchmarks
$ ./run.sh
This will run benchmarks the Python standard logger and for containerlog. The latest results
can be found below.
Benchmarks were measured using Python 3.8.0 on macOS 10.15.1 with a 2.9 GHz 6-Core Intel Core i9 processor and 16 GB 2400 MHz DDR4 memory.
| Benchmark | std logger (ns) | std proxy (ns) | containerlog (ns) |
|---|---|---|---|
| baseline | 0.68 +/- 0.02 | 0.69 +/- 0.01 | 0.7 +/- 0.02 |
| silent | 108.0 +/- 6.0 | 1140.0 +/- 50.0 | 51.7 +/- 1.7 |
| basic | 4750.0 +/- 160.0 | 1140.0 +/- 60.0 | 1070.0 +/- 50.0 |
| short-simple | 5370.0 +/- 160.0 | 1280.0 +/- 60.0 | 1330.0 +/- 60.0 |
| long-simple | 5280.0 +/- 180.0 | 1480.0 +/- 70.0 | 2120.0 +/- 60.0 |
| short-complex | 5630.0 +/- 170.0 | 1500.0 +/- 150.0 | 1480.0 +/- 80.0 |
| long-complex | 6900.0 +/- 190.0 | 2870.0 +/- 80.0 | 3260.0 +/- 80.0 |
| exception | 10400.0 +/- 300.0 | 4440.0 +/- 150.0 | 4370.0 +/- 500.0 |
While containerlog is intentionally feature-sparse, feature requests are welcome. Additionally,
if you can find any other ways to micro-optimize the codebase, pull requests are very much
appreciated.