# README
sfxclient
import "github.com/signalfx/golib/sfxclient"
Package signalfx creates convenient go functions and wrappers to send metrics to SignalFx.
The core of the library is HTTPSink which allows users to send metrics to SignalFx ad-hoc. A Scheduler is built on top of this to facility easy management of metrics for multiple SignalFx reporters at once in more complex libraries.
HTTPSink
The simplest way to send metrics to SignalFx is with HTTPSink. The only struct parameter that needs to be configured is AuthToken. To make it easier to create common Datapoint objects, wrappers exist for Gauge and Cumulative. An example of sending a hello world metric would look like as shown below.
Configuring your endpoints
If no endpoints are set manually, this library uses the us0 realm by default.
If you are not in this realm, you will need to explicitly set the
endpoint urls above as shown below. To determine if you are in a different realm and need to
explicitly set the endpoints, check your profile page in the SignalFx
web application. You will also need to specify an organization access token when making requests
with the client. For more information on access tokens,
see the API's authentication documentation.
func SendHelloWorld() {
client := NewHTTPSink()
// modify endpoints if needed
client.DatapointEndpoint = "https://ingest.{REALM}.signalfx.com/v2/datapoint"
client.EventEndpoint = "https://ingest.{REALM}.signalfx.com/v2/event"
client.TraceEndpoint = "https://ingest.{REALM}.signalfx.com/v1/trace"
client.AuthToken = "ORG_TOKEN"
ctx := context.Background()
client.AddDatapoints(ctx, []*datapoint.Datapoint{
GaugeF("hello.world", nil, 1.0),
})
dims = make(map[string]string)
client.AddEvents(ctx, []*event.Event{
event.New("hello.world", event.USERDEFINED, dims, time.Time{}),
})
}
Scheduler
To facilitate periodic sending of datapoints to SignalFx, a Scheduler abstraction exists. You can use this to report custom metrics to SignalFx at some periodic interval.
type CustomApplication struct {
queue chan int64
}
func (c *CustomApplication) Datapoints() []*datapoint.Datapoint {
return []*datapoint.Datapoint {
sfxclient.Gauge("queue.size", nil, len(queue)),
}
}
func main() {
scheduler := sfxclient.NewScheduler()
// endpoint configuration examples
scheduler.Sink.(*HTTPSink).DatapointEndpoint = "https://ingest.{REALM}.signalfx.com/v2/datapoint"
scheduler.Sink.(*HTTPSink).EventEndpoint = "https://ingest.{REALM}.signalfx.com/v2/event"
scheduler.Sink.(*HTTPSink).TraceEndpoint = "https://ingest.{REALM}.signalfx.com/v1/trace"
scheduler.Sink.(*HTTPSink).AuthToken = "ORG_TOKEN"
app := &CustomApplication{}
scheduler.AddCallback(app)
go scheduler.Schedule(context.Background())
}
RollingBucket and CumulativeBucket
Because counting things and calculating percentiles like p99 or median are common operations, RollingBucket and CumulativeBucket exist to make this easier. They implement the Collector interface which allows users to add them to an existing Scheduler.
Index
- Constants
- Variables
- func Cumulative
- func CumulativeF
- func CumulativeP
- func Gauge
- func GaugeF
- type Collector
- type CumulativeBucket
- type HTTPSink
- type HashableCollector
- type MultiCollector
- type Result
- type RollingBucket
- type Scheduler
- func NewScheduler
- func (*Scheduler) AddCallback
- func (*Scheduler) AddGroupedCallback
- func (*Scheduler) DefaultDimensions
- func (*Scheduler) GroupedDefaultDimensions
- func (*Scheduler) RemoveCallback
- func (*Scheduler) RemoveGroupedCallback
- func (*Scheduler) ReportOnce
- func (*Scheduler) ReportingDelay
- func (*Scheduler) Schedule
- func (*Scheduler) Var
- type Sink
- type WithDimensions
Constants
const ClientVersion = "1.0"
ClientVersion is the version of this library and is embedded into the user agent
const DefaultReportingDelay = time.Second * 20
DefaultReportingDelay is the default interval Scheduler users to report metrics to SignalFx
const DefaultTimeout = time.Second * 5
DefaultTimeout is the default time to fail signalfx datapoint requests if they don't succeed
const IngestEndpointV2 = "https://ingest.signalfx.com/v2/datapoint"
IngestEndpointV2 is the v2 version of the signalfx ingest endpoint
const TokenHeaderName = "X-Sf-Token"
TokenHeaderName is the header key for the auth token in the HTTP request
Variables
var DefaultBucketWidth = time.Second * 20
DefaultBucketWidth is the default width that a RollingBucket should flush histogram values
var DefaultErrorHandler = func(err error) error {
log.DefaultLogger.Log(log.Err, err, "Unable to handle error")
return nil
}
DefaultErrorHandler is the default way to handle errors by a scheduler. It simply prints them to stdout
var DefaultHistogramSize = 80
DefaultHistogramSize is the default number of windows RollingBucket uses for created histograms
var DefaultMaxBufferSize = 100
DefaultMaxBufferSize is the default number of past bucket Quantile values RollingBucket saves until a Datapoints() call
var DefaultQuantiles = []float64{.25, .5, .9, .99}
DefaultQuantiles are the default set of percentiles RollingBucket should collect
var DefaultUserAgent = fmt.Sprintf("golib-sfxclient/%s (gover %s)", ClientVersion, runtime.Version())
DefaultUserAgent is the UserAgent string sent to signalfx
func Cumulative
func Cumulative(metricName string, dimensions map[string]string, val int64) *datapoint.Datapoint
Cumulative creates a SignalFx cumulative counter for integer values.
func CumulativeF
func CumulativeF(metricName string, dimensions map[string]string, val float64) *datapoint.Datapoint
CumulativeF creates a SignalFx cumulative counter for float values.
func CumulativeP
func CumulativeP(metricName string, dimensions map[string]string, val *int64) *datapoint.Datapoint
CumulativeP creates a SignalFx cumulative counter for integer values from a pointer that is loaded atomically.
func Gauge
func Gauge(metricName string, dimensions map[string]string, val int64) *datapoint.Datapoint
Gauge creates a SignalFx gauge for integer values.
func GaugeF
func GaugeF(metricName string, dimensions map[string]string, val float64) *datapoint.Datapoint
GaugeF creates a SignalFx gauge for floating point values.
type Collector
type Collector interface {
Datapoints() []*datapoint.Datapoint
}
Collector is anything Scheduler can track that emits points
var GoMetricsSource Collector = &goMetrics{}
GoMetricsSource is a singleton Collector that collects basic go system stats. It currently collects from runtime.ReadMemStats and adds a few extra metrics like uptime of the process and other runtime package functions.
func NewMultiCollector
func NewMultiCollector(collectors ...Collector) Collector
NewMultiCollector returns a collector that is the aggregate of every given collector. It can be used to turn multiple collectors into a single collector.
type CumulativeBucket
type CumulativeBucket struct {
MetricName string
Dimensions map[string]string
}
A CumulativeBucket tracks groups of values, reporting the count/sum/sum of squares as a cumulative counter.
func (*CumulativeBucket) Add
func (b *CumulativeBucket) Add(val int64)
Add an item to the bucket, later reporting the result in the next report cycle.
func (*CumulativeBucket) Datapoints
func (b *CumulativeBucket) Datapoints() []*datapoint.Datapoint
Datapoints returns the count/sum/sumsquare datapoints, or nil if there is no set metric name
func (*CumulativeBucket) MultiAdd
func (b *CumulativeBucket) MultiAdd(res *Result)
MultiAdd many items into the bucket at once using a Result. This can be more efficient as it involves only a constant number of atomic operations.
type HTTPSink
type HTTPSink struct {
AuthToken string
UserAgent string
DatapointEndpoint string
EventEndpoint string
Client *http.Client
}
HTTPSink will accept signalfx datapoints and forward them to SignalFx via HTTP.
func NewHTTPSink
func NewHTTPSink() *HTTPSink
NewHTTPSink creates a default NewHTTPSink using package level constants as defaults, including an empty auth token. If sending directly to SiganlFx, you will be required to explicitly set the AuthToken
func (*HTTPSink) AddDatapoints
func (h *HTTPSink) AddDatapoints(ctx context.Context, points []*datapoint.Datapoint) (err error)
AddDatapoints forwards the datapoints to SignalFx.
func (*HTTPSink) AddEvents
func (h *HTTPSink) AddEvents(ctx context.Context, points []*event.Event) (err error)
AddEvents forwards the events to SignalFx.
type HashableCollector
type HashableCollector struct {
Callback func() []*datapoint.Datapoint
}
HashableCollector is a Collector function that can be inserted into a hashmap. You can use it to wrap a functional callback and insert it into a Scheduler.
func CollectorFunc
func CollectorFunc(callback func() []*datapoint.Datapoint) *HashableCollector
CollectorFunc wraps a function to make it a Collector.
func (*HashableCollector) Datapoints
func (h *HashableCollector) Datapoints() []*datapoint.Datapoint
Datapoints calls the wrapped function.
type MultiCollector
type MultiCollector []Collector
MultiCollector acts like a datapoint collector over multiple collectors.
func (MultiCollector) Datapoints
func (m MultiCollector) Datapoints() []*datapoint.Datapoint
Datapoints returns the datapoints from every collector.
type Result
type Result struct {
Count int64
Sum int64
SumOfSquares float64
}
Result is a cumulated result of items that can be added to a CumulativeBucket at once
func (*Result) Add
func (r *Result) Add(val int64)
Add a single number to the bucket. This does not use atomic operations and is not thread safe, but adding a finished Result into a CumulativeBucket is thread safe.
type RollingBucket
type RollingBucket struct {
// MetricName is the metric name used when the RollingBucket is reported to SignalFx
MetricName string
// Dimensions are the dimensions used when the RollingBucket is reported to SignalFx
Dimensions map[string]string
// Quantiles are an array of values [0 - 1.0] that are the histogram quantiles reported to
// SignalFx during a Datapoints() call. For example, [.5] would only report the median.
Quantiles []float64
// BucketWidth is how long in time a bucket accumulates values before a flush is forced
BucketWidth time.Duration
// Hist is an efficient tracker of numeric values for a histogram
Hist *gohistogram.NumericHistogram
// MaxFlushBufferSize is the maximum size of a window to keep for the RollingBucket before
// quantiles are dropped. It is ideally close to len(quantiles) * 3 + 15
MaxFlushBufferSize int
// Timer is used to track time.Now() during default value add calls
Timer timekeeper.TimeKeeper
}
RollingBucket keeps histogram style metrics over a BucketWidth window of time. It allows users to collect and report percentile metrics like like median or p99, as well as min/max/sum/count and sum of square from a set of points.
func NewRollingBucket
func NewRollingBucket(metricName string, dimensions map[string]string) *RollingBucket
NewRollingBucket creates a new RollingBucket using default values for Quantiles, BucketWidth, and the histogram tracker.
func (*RollingBucket) Add
func (r *RollingBucket) Add(v float64)
Add a value to the rolling bucket histogram. If the current time is already calculated, it may be more efficient to call AddAt in order to save another time.Time() call.
func (*RollingBucket) AddAt
func (r *RollingBucket) AddAt(v float64, t time.Time)
AddAt is like Add but also takes a time to pretend the value comes at.
func (*RollingBucket) Datapoints
func (r *RollingBucket) Datapoints() []*datapoint.Datapoint
Datapoints returns basic bucket stats every time and will only the first time called for each window return that window's points. For efficiency sake, Datapoints() will only return histogram window values once. Because of this, it is suggested to always forward datapoints returned by this call to SignalFx.
type Scheduler
type Scheduler struct {
Sink Sink
Timer timekeeper.TimeKeeper
SendZeroTime bool
ErrorHandler func(error) error
ReportingDelayNs int64
}
A Scheduler reports metrics to SignalFx at some timely manner.
func NewScheduler
func NewScheduler() *Scheduler
NewScheduler creates a default SignalFx scheduler that can report metrics to SignalFx at some interval.
func (*Scheduler) AddCallback
func (s *Scheduler) AddCallback(db Collector)
AddCallback adds a collector to the default group.
func (*Scheduler) AddGroupedCallback
func (s *Scheduler) AddGroupedCallback(group string, db Collector)
AddGroupedCallback adds a collector to a specific group.
func (*Scheduler) DefaultDimensions
func (s *Scheduler) DefaultDimensions(dims map[string]string)
DefaultDimensions adds a dimension map that are appended to all metrics in the default group.
func (*Scheduler) GroupedDefaultDimensions
func (s *Scheduler) GroupedDefaultDimensions(group string, dims map[string]string)
GroupedDefaultDimensions adds default dimensions to a specific group.
func (*Scheduler) RemoveCallback
func (s *Scheduler) RemoveCallback(db Collector)
RemoveCallback removes a collector from the default group.
func (*Scheduler) RemoveGroupedCallback
func (s *Scheduler) RemoveGroupedCallback(group string, db Collector)
RemoveGroupedCallback removes a collector from a specific group.
func (*Scheduler) ReportOnce
func (s *Scheduler) ReportOnce(ctx context.Context) error
ReportOnce will report any metrics saved in this reporter to SignalFx
func (*Scheduler) ReportingDelay
func (s *Scheduler) ReportingDelay(delay time.Duration)
ReportingDelay sets the interval metrics are reported to SignalFx.
func (*Scheduler) Schedule
func (s *Scheduler) Schedule(ctx context.Context) error
Schedule will run until either the ErrorHandler returns an error or the context is canceled. This is intended to be run inside a goroutine.
func (*Scheduler) Var
func (s *Scheduler) Var() expvar.Var
Var returns an expvar variable that prints the values of the previously reported datapoints.
type Sink
type Sink interface {
AddDatapoints(ctx context.Context, points []*datapoint.Datapoint) (err error)
}
Sink is anything that can receive points collected by a Scheduler. This can be useful for stubbing out your collector to test the points that will be sent to SignalFx.
type WithDimensions
type WithDimensions struct {
Dimensions map[string]string
Collector Collector
}
WithDimensions adds dimensions on top of the datapoints of a collector. This can be used to take an existing Collector and include extra dimensions.
func (*WithDimensions) Datapoints
func (w *WithDimensions) Datapoints() []*datapoint.Datapoint
Datapoints calls datapoints and adds on Dimensions