README
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Example API use
// Initialize a metric context
m := metrics.NewMetricContext("system")
// Create a basic counter, all ops are atomic
c := metrics.NewBasicCounter()
c.Add(n) // increment counter by delta n
c.Set(n) // Set counter value to n
// Create a new counter; has additional state associated with it
// to calculate rate
c := metrics.NewCounter()
c.Add(n) // increment counter by delta n
c.Set(n) // Set counter value to n
r := c.ComputeRate() // compute rate of change/sec
// Create a new gauge
// Set/Get acquire a mutex
c := metrics.NewGauge()
c.Set(12.0) // Set Value
c.Get() // get Value
// StatsTimer - useful for computing statistics on timed operations
s := metrics.NewStatsTimer()
t := s.Start() // returns a timer
s.Stop(t) // stop the timer
// Example
func (* Webapp) ServeRequest(uri string) error {
t := s.Start()
// do something
s.Stop(t)
}
pctile_75th, err := s.Percentile(75)
if err == nil {
fmt.Println("Percentile latency for 75 pctile: ", pctile_75th)
}
// Launch a goroutine to serve metrics via http json
go func() {
http.HandleFunc("/metrics.json", m.HttpJsonHandler)
http.ListenAndServe("localhost:12345", nil)
}
// Get metrics via http json.
resp, err := http.Get("http://localhost:12345/metrics.json")
##Dependencies Package dependency is managed by godep (https://github.com/tools/godep). Follow the docs there when adding/removing/updating package dependencies.
Documentation
¶
Index ¶
Constants ¶
const NOT_INITIALIZED = -1
const NS_IN_SEC = float64(time.Second)
nanoseconds in a second represented in float64
Variables ¶
var PERCENTILES = []float64{50, 75, 95, 99, 99.9, 99.99, 99.999}
default percentiles to compute when serializing statstimer type to stdout/json
var TICKS int64
Functions ¶
This section is empty.
Types ¶
type BasicCounter ¶
type BasicCounter uint64
func NewBasicCounter ¶
func NewBasicCounter() *BasicCounter
func (*BasicCounter) MarshalJSON ¶
func (c *BasicCounter) MarshalJSON() ([]byte, error)
MarshalJSON returns a byte slice of JSON representation of basiccounter
type Counter ¶
type Counter struct {
// contains filtered or unexported fields
}
Counters
func NewCounter ¶
func NewCounter() *Counter
Counters differ from BasicCounter by having additional fields for computing rate. Operations on counter hold a mutex. use BasicCounter if you need lock-free counters
func (*Counter) ComputeRate ¶
func (*Counter) MarshalJSON ¶
MarshalJSON returns a byte slice of JSON representation of counter
type Gauge ¶
type Gauge struct {
// contains filtered or unexported fields
}
Gauges
func (*Gauge) MarshalJSON ¶
MarshalJSON returns a byte slice of JSON representation of Gauge
type Int64Slice ¶
type Int64Slice []int64
func (Int64Slice) Len ¶
func (a Int64Slice) Len() int
func (Int64Slice) Less ¶
func (a Int64Slice) Less(i, j int) bool
func (Int64Slice) Swap ¶
func (a Int64Slice) Swap(i, j int)
type MetricContext ¶
type MetricContext struct {
Counters map[string]*Counter
Gauges map[string]*Gauge
BasicCounters map[string]*BasicCounter
StatsTimers map[string]*StatsTimer
OutputFilter OutputFilterFunc
// contains filtered or unexported fields
}
func NewMetricContext ¶
func NewMetricContext(namespace string) *MetricContext
func (*MetricContext) EncodeJSON ¶
func (m *MetricContext) EncodeJSON(w io.Writer) error
EncodeJSON is a streaming encoder that writes all metrics passing filter to writer w as JSON
func (*MetricContext) HttpJsonHandler ¶
func (m *MetricContext) HttpJsonHandler(w http.ResponseWriter, r *http.Request)
HttpJsonHandler setups a handler for exposing metrics via JSON over HTTP
func (*MetricContext) Register ¶
func (m *MetricContext) Register(v interface{}, name string)
Register(v Metric) registers a metric with metric context
func (*MetricContext) Unregister ¶
func (m *MetricContext) Unregister(v interface{}, name string)
Unregister(v Metric) unregisters a metric with metric context
type MetricJSON ¶
MetricJSON is a type for serializing any metric type
type OutputFilterFunc ¶
type StatsTimer ¶
type StatsTimer struct {
// contains filtered or unexported fields
}
func NewStatsTimer ¶
func NewStatsTimer(timeUnit time.Duration, nsamples int) *StatsTimer
func (*StatsTimer) MarshalJSON ¶
func (s *StatsTimer) MarshalJSON() ([]byte, error)
MarshalJSON returns a byte slice containing representation of StatsTimer
func (*StatsTimer) Percentile ¶
func (s *StatsTimer) Percentile(percentile float64) (float64, error)
func (*StatsTimer) Reset ¶
func (s *StatsTimer) Reset()
func (*StatsTimer) Start ¶
func (s *StatsTimer) Start() *Timer
func (*StatsTimer) Stop ¶
func (s *StatsTimer) Stop(t *Timer) float64
Source Files