Documentation
¶
Overview ¶
Package debugstats is a very small helper that makes it easy to **see** the raw metrics produced by github.com/segmentio/stats/v5 while you are debugging or developing a new instrumentation strategy.
- It implements the stats.Handler interface.
- Every metric that reaches the handler is written as a single line in a StatsD-like format (metric name, value, type, tags) followed by '\n'.
- A time-stamp (RFC-3339) is prepended so that the stream can later be correlated with logs if desired.
Destination ¶
By default the lines are written to os.Stdout, but any io.Writer can be supplied through the Client’s Dst field:
var buf bytes.Buffer
stats.Register(&debugstats.Client{Dst: &buf}) // write into a buffer
Grep-like filtering ¶
When you are only interested in a subset of your metrics you can pass a regular expression via the Grep field. Only the lines whose *full textual representation* match the regexp are emitted:
stats.Register(&debugstats.Client{
Grep: regexp.MustCompile(`^my_service\.http_requests_total`),
})
Quick example
func main() {
stats.Register(&debugstats.Client{}) // defaults to stdout
stats.Set("active_users", 42)
stats.Observe("compression_ratio", 0.28,
stats.T("codec", "zstd"),
stats.T("bucket", "10-100 kB"),
)
// Flush whenever you need a consistent snapshot:
stats.Flush()
}
Typical output (wrapped for readability):
2024-04-18T09:45:00Z active_users:42|g 2024-04-18T09:45:00Z compression_ratio:0.28|d|#bucket:10-100 kB,codec:zstd
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
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Functions ¶
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Types ¶
type Client ¶
Client will print out received metrics. If Dst is nil, metrics will be printed to stdout, otherwise they will be printed to Dst.
You can optionally provide a Grep regexp to limit printed metrics to ones matching the regular expression.
Example ¶
ExampleClient demonstrates how to register a debugstats.Client so that all produced metrics are echoed to stdout. The example purposefully omits an output check because the first column is a time-stamp whose value varies.
// Only show metrics whose name contains "foo".
stats.Register(&debugstats.Client{
Grep: regexp.MustCompile(`foo`),
})
stats.Set("foo_active_users", 123)
stats.Observe("bar_compression_ratio", 0.37) // <- this one is filtered out
// Flush to make sure the handler has processed everything before the
// program exits in short-lived examples or CLI tools.
stats.Flush()
Source Files