gotosocial/vendor/go.opentelemetry.io/otel/sdk/trace/provider.go
2024-08-26 18:05:54 +02:00

493 lines
15 KiB
Go

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
package trace // import "go.opentelemetry.io/otel/sdk/trace"
import (
"context"
"fmt"
"sync"
"sync/atomic"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/internal/global"
"go.opentelemetry.io/otel/sdk/instrumentation"
"go.opentelemetry.io/otel/sdk/resource"
"go.opentelemetry.io/otel/trace"
"go.opentelemetry.io/otel/trace/embedded"
"go.opentelemetry.io/otel/trace/noop"
)
const (
defaultTracerName = "go.opentelemetry.io/otel/sdk/tracer"
)
// tracerProviderConfig.
type tracerProviderConfig struct {
// processors contains collection of SpanProcessors that are processing pipeline
// for spans in the trace signal.
// SpanProcessors registered with a TracerProvider and are called at the start
// and end of a Span's lifecycle, and are called in the order they are
// registered.
processors []SpanProcessor
// sampler is the default sampler used when creating new spans.
sampler Sampler
// idGenerator is used to generate all Span and Trace IDs when needed.
idGenerator IDGenerator
// spanLimits defines the attribute, event, and link limits for spans.
spanLimits SpanLimits
// resource contains attributes representing an entity that produces telemetry.
resource *resource.Resource
}
// MarshalLog is the marshaling function used by the logging system to represent this Provider.
func (cfg tracerProviderConfig) MarshalLog() interface{} {
return struct {
SpanProcessors []SpanProcessor
SamplerType string
IDGeneratorType string
SpanLimits SpanLimits
Resource *resource.Resource
}{
SpanProcessors: cfg.processors,
SamplerType: fmt.Sprintf("%T", cfg.sampler),
IDGeneratorType: fmt.Sprintf("%T", cfg.idGenerator),
SpanLimits: cfg.spanLimits,
Resource: cfg.resource,
}
}
// TracerProvider is an OpenTelemetry TracerProvider. It provides Tracers to
// instrumentation so it can trace operational flow through a system.
type TracerProvider struct {
embedded.TracerProvider
mu sync.Mutex
namedTracer map[instrumentation.Scope]*tracer
spanProcessors atomic.Pointer[spanProcessorStates]
isShutdown atomic.Bool
// These fields are not protected by the lock mu. They are assumed to be
// immutable after creation of the TracerProvider.
sampler Sampler
idGenerator IDGenerator
spanLimits SpanLimits
resource *resource.Resource
}
var _ trace.TracerProvider = &TracerProvider{}
// NewTracerProvider returns a new and configured TracerProvider.
//
// By default the returned TracerProvider is configured with:
// - a ParentBased(AlwaysSample) Sampler
// - a random number IDGenerator
// - the resource.Default() Resource
// - the default SpanLimits.
//
// The passed opts are used to override these default values and configure the
// returned TracerProvider appropriately.
func NewTracerProvider(opts ...TracerProviderOption) *TracerProvider {
o := tracerProviderConfig{
spanLimits: NewSpanLimits(),
}
o = applyTracerProviderEnvConfigs(o)
for _, opt := range opts {
o = opt.apply(o)
}
o = ensureValidTracerProviderConfig(o)
tp := &TracerProvider{
namedTracer: make(map[instrumentation.Scope]*tracer),
sampler: o.sampler,
idGenerator: o.idGenerator,
spanLimits: o.spanLimits,
resource: o.resource,
}
global.Info("TracerProvider created", "config", o)
spss := make(spanProcessorStates, 0, len(o.processors))
for _, sp := range o.processors {
spss = append(spss, newSpanProcessorState(sp))
}
tp.spanProcessors.Store(&spss)
return tp
}
// Tracer returns a Tracer with the given name and options. If a Tracer for
// the given name and options does not exist it is created, otherwise the
// existing Tracer is returned.
//
// If name is empty, DefaultTracerName is used instead.
//
// This method is safe to be called concurrently.
func (p *TracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
// This check happens before the mutex is acquired to avoid deadlocking if Tracer() is called from within Shutdown().
if p.isShutdown.Load() {
return noop.NewTracerProvider().Tracer(name, opts...)
}
c := trace.NewTracerConfig(opts...)
if name == "" {
name = defaultTracerName
}
is := instrumentation.Scope{
Name: name,
Version: c.InstrumentationVersion(),
SchemaURL: c.SchemaURL(),
}
t, ok := func() (trace.Tracer, bool) {
p.mu.Lock()
defer p.mu.Unlock()
// Must check the flag after acquiring the mutex to avoid returning a valid tracer if Shutdown() ran
// after the first check above but before we acquired the mutex.
if p.isShutdown.Load() {
return noop.NewTracerProvider().Tracer(name, opts...), true
}
t, ok := p.namedTracer[is]
if !ok {
t = &tracer{
provider: p,
instrumentationScope: is,
}
p.namedTracer[is] = t
}
return t, ok
}()
if !ok {
// This code is outside the mutex to not hold the lock while calling third party logging code:
// - That code may do slow things like I/O, which would prolong the duration the lock is held,
// slowing down all tracing consumers.
// - Logging code may be instrumented with tracing and deadlock because it could try
// acquiring the same non-reentrant mutex.
global.Info("Tracer created", "name", name, "version", is.Version, "schemaURL", is.SchemaURL)
}
return t
}
// RegisterSpanProcessor adds the given SpanProcessor to the list of SpanProcessors.
func (p *TracerProvider) RegisterSpanProcessor(sp SpanProcessor) {
// This check prevents calls during a shutdown.
if p.isShutdown.Load() {
return
}
p.mu.Lock()
defer p.mu.Unlock()
// This check prevents calls after a shutdown.
if p.isShutdown.Load() {
return
}
current := p.getSpanProcessors()
newSPS := make(spanProcessorStates, 0, len(current)+1)
newSPS = append(newSPS, current...)
newSPS = append(newSPS, newSpanProcessorState(sp))
p.spanProcessors.Store(&newSPS)
}
// UnregisterSpanProcessor removes the given SpanProcessor from the list of SpanProcessors.
func (p *TracerProvider) UnregisterSpanProcessor(sp SpanProcessor) {
// This check prevents calls during a shutdown.
if p.isShutdown.Load() {
return
}
p.mu.Lock()
defer p.mu.Unlock()
// This check prevents calls after a shutdown.
if p.isShutdown.Load() {
return
}
old := p.getSpanProcessors()
if len(old) == 0 {
return
}
spss := make(spanProcessorStates, len(old))
copy(spss, old)
// stop the span processor if it is started and remove it from the list
var stopOnce *spanProcessorState
var idx int
for i, sps := range spss {
if sps.sp == sp {
stopOnce = sps
idx = i
}
}
if stopOnce != nil {
stopOnce.state.Do(func() {
if err := sp.Shutdown(context.Background()); err != nil {
otel.Handle(err)
}
})
}
if len(spss) > 1 {
copy(spss[idx:], spss[idx+1:])
}
spss[len(spss)-1] = nil
spss = spss[:len(spss)-1]
p.spanProcessors.Store(&spss)
}
// ForceFlush immediately exports all spans that have not yet been exported for
// all the registered span processors.
func (p *TracerProvider) ForceFlush(ctx context.Context) error {
spss := p.getSpanProcessors()
if len(spss) == 0 {
return nil
}
for _, sps := range spss {
select {
case <-ctx.Done():
return ctx.Err()
default:
}
if err := sps.sp.ForceFlush(ctx); err != nil {
return err
}
}
return nil
}
// Shutdown shuts down TracerProvider. All registered span processors are shut down
// in the order they were registered and any held computational resources are released.
// After Shutdown is called, all methods are no-ops.
func (p *TracerProvider) Shutdown(ctx context.Context) error {
// This check prevents deadlocks in case of recursive shutdown.
if p.isShutdown.Load() {
return nil
}
p.mu.Lock()
defer p.mu.Unlock()
// This check prevents calls after a shutdown has already been done concurrently.
if !p.isShutdown.CompareAndSwap(false, true) { // did toggle?
return nil
}
var retErr error
for _, sps := range p.getSpanProcessors() {
select {
case <-ctx.Done():
return ctx.Err()
default:
}
var err error
sps.state.Do(func() {
err = sps.sp.Shutdown(ctx)
})
if err != nil {
if retErr == nil {
retErr = err
} else {
// Poor man's list of errors
retErr = fmt.Errorf("%w; %w", retErr, err)
}
}
}
p.spanProcessors.Store(&spanProcessorStates{})
return retErr
}
func (p *TracerProvider) getSpanProcessors() spanProcessorStates {
return *(p.spanProcessors.Load())
}
// TracerProviderOption configures a TracerProvider.
type TracerProviderOption interface {
apply(tracerProviderConfig) tracerProviderConfig
}
type traceProviderOptionFunc func(tracerProviderConfig) tracerProviderConfig
func (fn traceProviderOptionFunc) apply(cfg tracerProviderConfig) tracerProviderConfig {
return fn(cfg)
}
// WithSyncer registers the exporter with the TracerProvider using a
// SimpleSpanProcessor.
//
// This is not recommended for production use. The synchronous nature of the
// SimpleSpanProcessor that will wrap the exporter make it good for testing,
// debugging, or showing examples of other feature, but it will be slow and
// have a high computation resource usage overhead. The WithBatcher option is
// recommended for production use instead.
func WithSyncer(e SpanExporter) TracerProviderOption {
return WithSpanProcessor(NewSimpleSpanProcessor(e))
}
// WithBatcher registers the exporter with the TracerProvider using a
// BatchSpanProcessor configured with the passed opts.
func WithBatcher(e SpanExporter, opts ...BatchSpanProcessorOption) TracerProviderOption {
return WithSpanProcessor(NewBatchSpanProcessor(e, opts...))
}
// WithSpanProcessor registers the SpanProcessor with a TracerProvider.
func WithSpanProcessor(sp SpanProcessor) TracerProviderOption {
return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
cfg.processors = append(cfg.processors, sp)
return cfg
})
}
// WithResource returns a TracerProviderOption that will configure the
// Resource r as a TracerProvider's Resource. The configured Resource is
// referenced by all the Tracers the TracerProvider creates. It represents the
// entity producing telemetry.
//
// If this option is not used, the TracerProvider will use the
// resource.Default() Resource by default.
func WithResource(r *resource.Resource) TracerProviderOption {
return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
var err error
cfg.resource, err = resource.Merge(resource.Environment(), r)
if err != nil {
otel.Handle(err)
}
return cfg
})
}
// WithIDGenerator returns a TracerProviderOption that will configure the
// IDGenerator g as a TracerProvider's IDGenerator. The configured IDGenerator
// is used by the Tracers the TracerProvider creates to generate new Span and
// Trace IDs.
//
// If this option is not used, the TracerProvider will use a random number
// IDGenerator by default.
func WithIDGenerator(g IDGenerator) TracerProviderOption {
return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
if g != nil {
cfg.idGenerator = g
}
return cfg
})
}
// WithSampler returns a TracerProviderOption that will configure the Sampler
// s as a TracerProvider's Sampler. The configured Sampler is used by the
// Tracers the TracerProvider creates to make their sampling decisions for the
// Spans they create.
//
// This option overrides the Sampler configured through the OTEL_TRACES_SAMPLER
// and OTEL_TRACES_SAMPLER_ARG environment variables. If this option is not used
// and the sampler is not configured through environment variables or the environment
// contains invalid/unsupported configuration, the TracerProvider will use a
// ParentBased(AlwaysSample) Sampler by default.
func WithSampler(s Sampler) TracerProviderOption {
return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
if s != nil {
cfg.sampler = s
}
return cfg
})
}
// WithSpanLimits returns a TracerProviderOption that configures a
// TracerProvider to use the SpanLimits sl. These SpanLimits bound any Span
// created by a Tracer from the TracerProvider.
//
// If any field of sl is zero or negative it will be replaced with the default
// value for that field.
//
// If this or WithRawSpanLimits are not provided, the TracerProvider will use
// the limits defined by environment variables, or the defaults if unset.
// Refer to the NewSpanLimits documentation for information about this
// relationship.
//
// Deprecated: Use WithRawSpanLimits instead which allows setting unlimited
// and zero limits. This option will be kept until the next major version
// incremented release.
func WithSpanLimits(sl SpanLimits) TracerProviderOption {
if sl.AttributeValueLengthLimit <= 0 {
sl.AttributeValueLengthLimit = DefaultAttributeValueLengthLimit
}
if sl.AttributeCountLimit <= 0 {
sl.AttributeCountLimit = DefaultAttributeCountLimit
}
if sl.EventCountLimit <= 0 {
sl.EventCountLimit = DefaultEventCountLimit
}
if sl.AttributePerEventCountLimit <= 0 {
sl.AttributePerEventCountLimit = DefaultAttributePerEventCountLimit
}
if sl.LinkCountLimit <= 0 {
sl.LinkCountLimit = DefaultLinkCountLimit
}
if sl.AttributePerLinkCountLimit <= 0 {
sl.AttributePerLinkCountLimit = DefaultAttributePerLinkCountLimit
}
return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
cfg.spanLimits = sl
return cfg
})
}
// WithRawSpanLimits returns a TracerProviderOption that configures a
// TracerProvider to use these limits. These limits bound any Span created by
// a Tracer from the TracerProvider.
//
// The limits will be used as-is. Zero or negative values will not be changed
// to the default value like WithSpanLimits does. Setting a limit to zero will
// effectively disable the related resource it limits and setting to a
// negative value will mean that resource is unlimited. Consequentially, this
// means that the zero-value SpanLimits will disable all span resources.
// Because of this, limits should be constructed using NewSpanLimits and
// updated accordingly.
//
// If this or WithSpanLimits are not provided, the TracerProvider will use the
// limits defined by environment variables, or the defaults if unset. Refer to
// the NewSpanLimits documentation for information about this relationship.
func WithRawSpanLimits(limits SpanLimits) TracerProviderOption {
return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
cfg.spanLimits = limits
return cfg
})
}
func applyTracerProviderEnvConfigs(cfg tracerProviderConfig) tracerProviderConfig {
for _, opt := range tracerProviderOptionsFromEnv() {
cfg = opt.apply(cfg)
}
return cfg
}
func tracerProviderOptionsFromEnv() []TracerProviderOption {
var opts []TracerProviderOption
sampler, err := samplerFromEnv()
if err != nil {
otel.Handle(err)
}
if sampler != nil {
opts = append(opts, WithSampler(sampler))
}
return opts
}
// ensureValidTracerProviderConfig ensures that given TracerProviderConfig is valid.
func ensureValidTracerProviderConfig(cfg tracerProviderConfig) tracerProviderConfig {
if cfg.sampler == nil {
cfg.sampler = ParentBased(AlwaysSample())
}
if cfg.idGenerator == nil {
cfg.idGenerator = defaultIDGenerator()
}
if cfg.resource == nil {
cfg.resource = resource.Default()
}
return cfg
}