beam: github.com/apache/beam/sdks/go/pkg/beam/core/metrics Index | Files

package metrics

import "github.com/apache/beam/sdks/go/pkg/beam/core/metrics"

Package metrics implements the Beam metrics API, described at http://s.apache.org/beam-metrics-api

Metrics in the Beam model are uniquely identified by a namespace, a name, and the PTransform context in which they are used. Further, they are reported as a delta against the bundle being processed, so that overcounting doesn't occur if a bundle needs to be retried. Each metric is scoped to their bundle, and ptransform.

Cells (or metric cells) are defined for each Beam model metric type, and the serve as concurrency safe storage of a given metric's values. Proxys are exported values representing the metric, for use in user ptransform code. They don't retain their cells, since they don't have the context to be able to store them for export back to the pipeline runner.

Metric cells aren't initialized until their first mutation, which follows from the Beam model design, where metrics are only sent for a bundle if they have changed. This is particularly convenient for distributions which means their min and max fields can be set to the first value on creation rather than have some marker of uninitialized state, which would otherwise need to be checked for on every update.

Metric values are implemented as lightweight proxies of the user provided namespace and name. This allows them to be declared globally, and used in any ParDo. Further, as per the design, they can be declared dynamically at runtime.

To handle reporting deltas on the metrics by bundle, metrics are keyed by bundleID,PTransformID,namespace, and name, so metrics that are identical except for bundles are treated as distinct, effectively providing per bundle deltas, since a new value cell is used per bundle.

Index

Package Files

metrics.go

func Clear Uses

func Clear()

Clear resets all storage associated with metrics for tests. Calling this in pipeline code leads to inaccurate metrics.

func ClearBundleData Uses

func ClearBundleData(b string)

ClearBundleData removes stored references associated with a given bundle, so it can be garbage collected.

func DumpToLog Uses

func DumpToLog(ctx context.Context)

DumpToLog is a debugging function that outputs all metrics available locally to beam.Log.

func DumpToOut Uses

func DumpToOut()

DumpToOut is a debugging function that outputs all metrics available locally to std out.

func SetBundleID Uses

func SetBundleID(ctx context.Context, id string) context.Context

SetBundleID sets the id of the current Bundle.

func SetPTransformID Uses

func SetPTransformID(ctx context.Context, id string) context.Context

SetPTransformID sets the id of the current PTransform. Must only be called on a context returened by SetBundleID.

func ToProto Uses

func ToProto(b, pt string) []*fnexecution_v1.Metrics_User

ToProto exports all collected metrics for the given BundleID and PTransform ID pair.

type Counter Uses

type Counter struct {
    // contains filtered or unexported fields
}

Counter is a simple counter for incrementing and decrementing a value.

func NewCounter Uses

func NewCounter(ns, n string) *Counter

NewCounter returns the Counter with the given namespace and name.

func (*Counter) Dec Uses

func (m *Counter) Dec(ctx context.Context, v int64)

Dec decrements the counter within the given PTransform context by v.

func (*Counter) Inc Uses

func (m *Counter) Inc(ctx context.Context, v int64)

Inc increments the counter within the given PTransform context by v.

func (*Counter) String Uses

func (m *Counter) String() string

type Distribution Uses

type Distribution struct {
    // contains filtered or unexported fields
}

Distribution is a simple distribution of values.

func NewDistribution Uses

func NewDistribution(ns, n string) *Distribution

NewDistribution returns the Distribution with the given namespace and name.

func (*Distribution) String Uses

func (m *Distribution) String() string

func (*Distribution) Update Uses

func (m *Distribution) Update(ctx context.Context, v int64)

Update updates the distribution within the given PTransform context with v.

type Gauge Uses

type Gauge struct {
    // contains filtered or unexported fields
}

Gauge is a time, value pair metric.

func NewGauge Uses

func NewGauge(ns, n string) *Gauge

NewGauge returns the Gauge with the given namespace and name.

func (*Gauge) Set Uses

func (m *Gauge) Set(ctx context.Context, v int64)

Set sets the gauge to the given value, and associates it with the current time on the clock.

func (*Gauge) String Uses

func (m *Gauge) String() string

Package metrics imports 11 packages (graph) and is imported by 4 packages. Updated 2020-01-25. Refresh now. Tools for package owners.