Documentation
¶
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var NonNegativeBuckets = []float64{
1, 2, 5,
10, 20, 50,
100, 200, 500,
1000, 2000, 5000,
10000, 20000, 50000,
100000, 200000, 500000,
1000000, 2000000, 5000000,
10000000, 20000000, 50000000,
100000000, 200000000, 500000000,
1000000000, 2000000000, 5000000000,
10000000000, 20000000000, 50000000000,
100000000000, 200000000000, 500000000000,
1000000000000, 2000000000000, 5000000000000,
10000000000000, 20000000000000, 50000000000000,
100000000000000, 200000000000000, 500000000000000,
1000000000000000, 2000000000000000, 5000000000000000,
10000000000000000, 20000000000000000, 50000000000000000,
100000000000000000, 200000000000000000, 500000000000000000,
1000000000000000000, 2000000000000000000, 5000000000000000000,
10000000000000000000, 20000000000000000000, 50000000000000000000,
}
NonNegativeBuckets provides rounded bucket boundaries for histograms that will only store non-negative values.
Functions ¶
This section is empty.
Types ¶
type Counter ¶
type Counter struct {
// contains filtered or unexported fields
}
A Counter is a float-valued, monotonically increasing metric. For example, you can use a Counter to count the number of requests received, the number of requests that resulted in an error, etc.
func NewCounter ¶
NewCounter returns a new Counter. It is typically called during package initialization since it panics if called more than once in the same process with the same name. Use NewCounterMap to make a Counter with labels.
type CounterMap ¶
type CounterMap[L comparable] struct { // contains filtered or unexported fields }
A CounterMap is a collection of Counters with the same name and label schema but with different label values.
Labels ¶
Labels are represented as a comparable struct of type L. We say a label struct L is valid if every field of L is a string, bool or integer type and is exported. For example, the following are valid label structs:
struct{} // an empty struct
struct{X string} // a struct with one field
struct{X, Y int} // a struct with two fields
The following are invalid label structs:
struct{x string} // unexported field
string // not a struct
struct{X chan int} // unsupported label type (i.e. chan int)
Note that the order of the fields within a label struct is unimportant. For example, if one program exports metric foo with labels struct{X, Y string}, another program can safely export the same metric with labels struct{Y, X string}.
By default, the first letter of every label names is lowercased. You can use the "weaver" struct tag to override this behavior and assign a different name to a label. For example,
struct {
Foo string // "foo"
Bar string `weaver:"Bar"` // "Bar"
Baz string `weaver:"sup"` // "sup"
}
Example ¶
package main
import (
"github.com/ServiceWeaver/weaver/metrics"
)
func main() {
// At package scope.
type carLabels struct {
Make string
Model string
}
var (
carCounts = metrics.NewCounterMap[carLabels]("car_count", "The number of cars")
civicCount = carCounts.Get(carLabels{"Honda", "Civic"})
camryCount = carCounts.Get(carLabels{"Toyota", "Camry"})
f150Count = carCounts.Get(carLabels{"Ford", "F-150"})
)
// In your code.
civicCount.Add(1)
camryCount.Add(2)
f150Count.Add(150)
}
Output:
func NewCounterMap ¶
func NewCounterMap[L comparable](name, help string) *CounterMap[L]
NewCounterMap returns a new CounterMap. It is typically called during package initialization since it panics if called more than once in the same process with the same name.
func (*CounterMap[L]) Get ¶
func (c *CounterMap[L]) Get(labels L) *Counter
Get returns the Counter with the provided labels, constructing it if it doesn't already exist. Multiple calls to Get with the same labels will return the same Counter.
func (*CounterMap[L]) Name ¶
func (c *CounterMap[L]) Name() string
Name returns the name of the CounterMap.
type Gauge ¶
type Gauge struct {
// contains filtered or unexported fields
}
A Gauge is a float-valued metric that can hold an arbitrary numerical value, which can increase or decrease over time. For example, you can use a Gauge to measure the current memory usage or the current number of outstanding requests.
func NewGauge ¶
NewGauge returns a new Gauge. It is typically called during package initialization since it panics if called more than once in the same process with the same name. Use NewGaugeMap to make a Gauge with labels.
type GaugeMap ¶
type GaugeMap[L comparable] struct { // contains filtered or unexported fields }
A GaugeMap is a collection of Gauges with the same name and label schema but with different label values. See CounterMap for a description of L.
Example ¶
package main
import (
"github.com/ServiceWeaver/weaver/metrics"
)
func main() {
// At package scope.
type tempLabels struct {
Room string
Index int
}
var (
temps = metrics.NewGaugeMap[tempLabels]("temperature", "Temperature, in Fahrenheit")
livingRoomTemp = temps.Get(tempLabels{"Living Room", 0})
bathroomTemp = temps.Get(tempLabels{"Bathroom", 0})
bedroom0Temp = temps.Get(tempLabels{"Bedroom", 0})
bedroom1Temp = temps.Get(tempLabels{"Bedroom", 1})
)
// In your code.
livingRoomTemp.Set(78.4)
bathroomTemp.Set(65.3)
bedroom0Temp.Set(84.1)
bedroom1Temp.Set(80.9)
livingRoomTemp.Add(1.2)
bathroomTemp.Sub(2.1)
}
Output:
func NewGaugeMap ¶
func NewGaugeMap[L comparable](name, help string) *GaugeMap[L]
NewGaugeMap returns a new GaugeMap. It is typically called during package initialization since it panics if called more than once in the same process with the same name.
type Histogram ¶
type Histogram struct {
// contains filtered or unexported fields
}
A Histogram is a metric that counts the number of values that fall in specified ranges (i.e. buckets). For example, you can use a Histogram to measure the distribution of request latencies.
func NewHistogram ¶
NewHistogram returns a new Histogram. It is typically called during package initialization since it panics if called more than once in the same process with the same name. Use NewHistogram to make a Histogram with labels.
The bucket boundaries must be strictly increasing. Given n boundary values, the histogram will contain n+1 buckets, organized as follows:
- bucket[0] is the underflow bucket, which counts values in the range [-inf, bounds[0]).
- bucket[n] is the overflow bucket, which counts values in the range [bounds[n-1], +inf).
- bucket[i], for 0 < i < n, is a bucket that counts values in the range [bounds[i-1], bounds[i]).
For example, given the bounds [0, 10, 100], we have the following buckets:
- Bucket 0: (-inf, 0]
- Bucket 1: [0, 10)
- Bucket 2: [10, 100)
- Bucket 3: [100, +inf)
type HistogramMap ¶
type HistogramMap[L comparable] struct { // contains filtered or unexported fields }
A HistogramMap is a collection of Histograms with the same name and label schema but with different label values. See CounterMap for a description of L.
Example ¶
package main
import (
"github.com/ServiceWeaver/weaver/metrics"
)
func main() {
// At package scope.
type latencyLabels struct {
Endpoint string
}
var (
latencies = metrics.NewHistogramMap[latencyLabels](
"http_request_latency_nanoseconds",
"HTTP request latency, in nanoseconds, by endpoint",
[]float64{10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000},
)
fooLatency = latencies.Get(latencyLabels{"/foo"})
barLatency = latencies.Get(latencyLabels{"/bar"})
metricsLatency = latencies.Get(latencyLabels{"/metrics"})
)
// In your code.
fooLatency.Put(8714.5)
barLatency.Put(491.7)
metricsLatency.Put(375.0)
}
Output:
func NewHistogramMap ¶
func NewHistogramMap[L comparable](name, help string, bounds []float64) *HistogramMap[L]
NewHistogramMap returns a new HistogramMap. It is typically called during package initialization since it panics if called more than once in the same process with the same name.
func (*HistogramMap[L]) Get ¶
func (h *HistogramMap[L]) Get(labels L) *Histogram
Get returns the Histogram with the provided labels, constructing it if it doesn't already exist. Multiple calls to Get with the same labels will return the same Histogram.
func (*HistogramMap[L]) Name ¶
func (h *HistogramMap[L]) Name() string
Name returns the name of the HistogramMap.
Source Files