dipstick
A fast and modular metrics library decoupling app instrumentation from reporting backend. Similar to popular logging frameworks, but with counters and timers. Can be configured for combined outputs (log + statsd), random sampling, local aggregation of metrics, recurrent background publication, etc.
Design
Dipstick's design goals are to:
- support as many metrics backends as possible while favoring none
- support all types of applications, from embedded to servers
- promote metrics conventions that facilitate app monitoring and maintenance
- stay out of the way in the code and at runtime (ergonomic, fast, resilient)
Code
Here's an example showing usage of a predefined timer with closure syntax. Each timer value is :
- Written immediately to the "app_metrics" logger.
- Sent to statsd immediately, one time out of ten (randomly sampled).
use *;
let app_metrics = metrics;
let timer = app_metrics.timer;
let value2 = time!;
In this other example, an ad-hoc timer with macro syntax is used.
- Each new timer value is aggregated with the previous values.
- Aggregation tracks count, sum, max and min values (locklessly).
- Aggregated scores are written to log every 10 seconds.
cache(sink)
is used to prevent metrics of the same to be created multiple times.
use *;
use Duration;
let = aggregate;
let app_metrics = metrics;
publish.publish_every;
let value2 = time!;
Other example(s?) can be found in the /examples dir.
Performance
Predefined timers use a bit more code but are generally faster because their
initialization cost is is only paid once.
Ad-hoc timers are redefined "inline" on each use. They are more flexible, but have more overhead because their init cost is paid on each use.
Defining a metric cache()
reduces that cost for recurring metrics.
Run benchmarks with cargo +nightly bench --features bench
.
TODO
Although already usable, Dipstick is still under heavy development and makes no guarantees of any kind at this point. See the following list for any potential caveats :
- META turn TODOs into GitHub issues
- generic publisher / sources
- dispatch scopes
- feature flags
- derive stats
- non-tokio publish scheduler
- microsecond-precision intervals
- heartbeat metric on publish
- logger templates
- configurable aggregation
- non-aggregating buffers
- tagged / ad-hoc metrics
- framework glue (rocket, iron, gotham, indicatif, etc.)
- more tests & benchmarks
- complete doc / inline samples
- more example apps
- A cool logo
- method annotation processors
#[timer("name")]