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StatsD-Bridge StatsD-Bridge
============= =============
StatsD-Bridge allows receiving StatsD-style metrics and exporting them as Prometheus metrics. StatsD-Bridge receives StatsD-style metrics and exporting them as Prometheus metrics.
## Overview
To pipe metrics from an existing StatsD environment into Prometheus, configure StatsD's repeater backend to repeat all received packets to a StatsD-Bridge process. This bridge translates StatsD metrics to Prometheus metrics via configured mapping rules.
+----------+ +-----------------+ +--------------+
| StatsD |---(UDP repeater)--->| StatsD-Bridge |<---(scrape /metrics)---| Prometheus |
+----------+ +-----------------+ +--------------+
## Building and Running
$ go build
$ ./statsd_bridge --help
Usage of ./statsd_bridge:
-listeningAddress=":8080": The address on which to expose generated Prometheus metrics.
-mappingConfig="mapping.conf": Metric mapping configuration file name.
-statsdListeningAddress=":8126": The UDP address on which to receive statsd metric lines.
-summaryFlushInterval=15m0s: How frequently to reset all summary metrics.
## Tests
$ go test
## Metric Mapping and Configuration
The StatsD-Bridge can be configured to translate specific dot-separated StatsD metrics into labeled Prometheus metrics via a simple mapping language. A mapping definition starts with a line matching the StatsD metric in question, with `*`s acting as wildcards for each dot-separated metric component. The lines following the matching expression must contain one `label="value"` pair each, and at least define the metric name (label name `name`). The Prometheus metric is then constructed from these labels. `$n`-style references in the label value are replaced by the n-th wildcard match in the matching line, starting at 1. Multiple matching definitions are separated by one or more empty lines. The first mapping rule that matches a StatsD metric wins.
An example mapping configuration:
test.dispatcher.*.*.*
name="dispatcher_events"
processor="$1"
action="$2"
outcome="$3"
job="test_dispatcher"
*.signup.*.*
name="signup_events"
provider="$2"
outcome="$3"
job="$1_server"
This would transform these example StatsD metrics as into Prometheus metrics as follows:
test.dispatcher.FooProcessor.send.success
=> dispatcher_events{processor="FooProcessor", action="send", outcome="success", job="test_dispatcher"}
foo_product.signup.facebook.failure
=> signup_events{provider="facebook", outcome="failure", job="foo_product_server"}
Metrics that don't match any mapping in the configuration file are translated into Prometheus metrics without any labels and with certain characters escaped (`_` -> `__`; `-` -> `__`; `.` -> `_`).
In general, the different metric types are translated as follows, with certain suffixes appended to the Prometheus metric names:
StatsD gauge -> Prometheus gauge (suffix `_gauge`)
StatsD counter -> Prometheus counter (suffix `_counter`)
StatsD timer -> Prometheus summary (suffix `_timer`) <-- indicates timer quantiles
-> Prometheus counter (suffix `_timer_total`) <-- indicates total time spent
-> Prometheus counter (suffix `_timer_count`) <-- indicates total number of timer events