Documentation ¶
Overview ¶
Package tracer contains Datadog's core tracing client. It is used to trace requests as they flow across web servers, databases and microservices, giving developers visibility into bottlenecks and troublesome requests. To start the tracer, simply call the start method along with an optional set of options. By default, the trace agent is considered to be found at "localhost:8126". In a setup where this would be different (let's say 127.0.0.1:1234), we could do:
tracer.Start(tracer.WithAgentAddr("127.0.0.1:1234")) defer tracer.Stop()
The tracing client can perform trace sampling. While the trace agent already samples traces to reduce bandwidth usage, client sampling reduces performance overhead. To make use of it, the package comes with a ready-to-use rate sampler that can be passed to the tracer. To use it and keep only 30% of the requests, one would do:
s := tracer.NewRateSampler(0.3) tracer.Start(tracer.WithSampler(s))
More precise control of sampling rates can be configured using sampling rules. This can be applied based on span name, service or both, and is used to determine the sampling rate to apply. MaxPerSecond specifies max number of spans per second that can be sampled per the rule and applies only to sampling rules of type tracer.SamplingRuleSpan. If MaxPerSecond is not specified, the default is no limit.
rules := []tracer.SamplingRule{ // sample 10% of traces with the span name "web.request" tracer.NameRule("web.request", 0.1), // sample 20% of traces for the service "test-service" tracer.ServiceRule("test-service", 0.2), // sample 30% of traces when the span name is "db.query" and the service // is "postgres.db" tracer.NameServiceRule("db.query", "postgres.db", 0.3), // sample 100% of traces when service and name match these regular expressions {Service: regexp.MustCompile("^test-"), Name: regexp.MustCompile("http\\..*"), Rate: 1.0}, // sample 50% of spans when service and name match these glob patterns with no limit on the number of spans tracer.SpanNameServiceRule("^test-", "http\\..*", 0.5), // sample 50% of spans when service and name match these glob patterns up to 100 spans per second tracer.SpanNameServiceMPSRule("^test-", "http\\..*", 0.5, 100), } tracer.Start(tracer.WithSamplingRules(rules)) defer tracer.Stop()
Sampling rules can also be configured at runtime using the DD_TRACE_SAMPLING_RULES and DD_SPAN_SAMPLING_RULES environment variables. When set, it overrides rules set by tracer.WithSamplingRules. The value is a JSON array of objects. For trace sampling rules, the "sample_rate" field is required, the "name" and "service" fields are optional. For span sampling rules, the "name" and "service", if specified, must be a valid glob pattern, i.e. a string where "*" matches any contiguous substring, even an empty string, and "?" character matches exactly one of any character. The "sample_rate" field is optional, and if not specified, defaults to "1.0", sampling 100% of the spans. The "max_per_second" field is optional, and if not specified, defaults to 0, keeping all the previously sampled spans.
export DD_TRACE_SAMPLING_RULES='[{"name": "web.request", "sample_rate": 1.0}]' export DD_SPAN_SAMPLING_RULES='[{"service":"test.?","name": "web.*", "sample_rate": 1.0, "max_per_second":100}]'
To create spans, use the functions StartSpan and StartSpanFromContext. Both accept StartSpanOptions that can be used to configure the span. A span that is started with no parent will begin a new trace. See the function documentation for details on specific usage. Each trace has a hard limit of 100,000 spans, after which the trace will be dropped and give a diagnostic log message. In practice users should not approach this limit as traces of this size are not useful and impossible to visualize.
See the contrib package ( https://pkg.go.dev/github.com/DataDog/dd-trace-go/v2/contrib ) for integrating datadog with various libraries, frameworks and clients.
All spans created by the tracer contain a context hereby referred to as the span context. Note that this is different from Go's context. The span context is used to package essential information from a span, which is needed when creating child spans that inherit from it. Thus, a child span is created from a span's span context. The span context can originate from within the same process, but also a different process or even a different machine in the case of distributed tracing.
To make use of distributed tracing, a span's context may be injected via a carrier into a transport (HTTP, RPC, etc.) to be extracted on the other end and used to create spans that are direct descendants of it. A couple of carrier interfaces which should cover most of the use-case scenarios are readily provided, such as HTTPCarrier and TextMapCarrier. Users are free to create their own, which will work with our propagation algorithm as long as they implement the TextMapReader and TextMapWriter interfaces. An example alternate implementation is the MDCarrier in our gRPC integration.
As an example, injecting a span's context into an HTTP request would look like this. (See the net/http contrib package for more examples https://pkg.go.dev/github.com/DataDog/dd-trace-go/v2/contrib/net/http):
req, err := http.NewRequest("GET", "http://example.com", nil) // ... err := tracer.Inject(span.Context(), tracer.HTTPHeadersCarrier(req.Header)) // ... http.DefaultClient.Do(req)
Then, on the server side, to continue the trace one would do:
sctx, err := tracer.Extract(tracer.HTTPHeadersCarrier(req.Header)) // ... span := tracer.StartSpan("child.span", tracer.ChildOf(sctx))
In the same manner, any means can be used as a carrier to inject a context into a transport. Go's context can also be used as a means to transport spans within the same process. The methods StartSpanFromContext, ContextWithSpan and SpanFromContext exist for this reason.
Some libraries and frameworks are supported out-of-the-box by using one of our integrations. You can see a list of supported integrations here: https://godoc.org/github.com/DataDog/dd-trace-go/v2/contrib
Example ¶
A basic example demonstrating how to start the tracer, as well as how to create a root span and a child span that is a descendant of it.
// Unless explicitly stated otherwise all files in this repository are licensed // under the Apache License Version 2.0. // This product includes software developed at Datadog (https://www.datadoghq.com/). // Copyright 2016 Datadog, Inc. package main import ( "context" "fmt" "time" "github.com/DataDog/dd-trace-go/v2/ddtrace/ext" "github.com/DataDog/dd-trace-go/v2/ddtrace/tracer" ) // A basic example demonstrating how to start the tracer, as well as how // to create a root span and a child span that is a descendant of it. func main() { ctx, cancel := context.WithTimeout(context.Background(), time.Second) defer cancel() // Start the tracer and defer the Stop method. tracer.Start() defer tracer.Stop() // Start a root span. span, ctx := tracer.StartSpanFromContext(ctx, "parent") defer span.Finish() // Run some code. err := doSomething(ctx) if err != nil { panic(err) } } func doSomething(ctx context.Context) (err error) { // Create a child, using the context of the parent span. span, ctx := tracer.StartSpanFromContext(ctx, "do.something", tracer.Tag(ext.ResourceName, "alarm")) defer func() { span.Finish(tracer.WithError(err)) }() // Perform an operation. select { case <-time.After(5 * time.Millisecond): fmt.Println("ding!") case <-ctx.Done(): fmt.Println("timed out :(") } return ctx.Err() }
Output:
Index ¶
- Constants
- Variables
- func ContextWithSpan(ctx context.Context, s Span) context.Context
- func Extract(carrier interface{}) (ddtrace.SpanContext, error)
- func Flush()
- func Inject(ctx ddtrace.SpanContext, carrier interface{}) error
- func MarkIntegrationImported(integration string) bool
- func SetDataStreamsCheckpoint(ctx context.Context, edgeTags ...string) (outCtx context.Context, ok bool)
- func SetDataStreamsCheckpointWithParams(ctx context.Context, params options.CheckpointParams, edgeTags ...string) (outCtx context.Context, ok bool)
- func SetUser(s Span, id string, opts ...UserMonitoringOption)
- func Start(opts ...StartOption) error
- func Stop()
- func TrackKafkaCommitOffset(group, topic string, partition int32, offset int64)
- func TrackKafkaProduceOffset(topic string, partition int32, offset int64)
- type DBMPropagationMode
- type FinishOption
- type HTTPHeadersCarrier
- type Propagator
- type PropagatorConfig
- type RateSampler
- type SQLCommentCarrier
- type SQLCommentInjectionModedeprecated
- type Sampler
- type SamplingRule
- func NameRule(name string, rate float64) SamplingRule
- func NameServiceRule(name string, service string, rate float64) SamplingRule
- func RateRule(rate float64) SamplingRule
- func ServiceRule(service string, rate float64) SamplingRule
- func SpanNameServiceMPSRule(name, service string, rate, limit float64) SamplingRule
- func SpanNameServiceRule(name, service string, rate float64) SamplingRule
- type SamplingRuleType
- type Span
- type StartOption
- func WithAgentAddr(addr string) StartOption
- func WithAgentURL(agentURL string) StartOption
- func WithAnalytics(on bool) StartOption
- func WithAnalyticsRate(rate float64) StartOption
- func WithDebugMode(enabled bool) StartOption
- func WithDebugSpansMode(timeout time.Duration) StartOption
- func WithDebugStack(enabled bool) StartOption
- func WithDogstatsdAddress(addr string) StartOption
- func WithEnv(env string) StartOption
- func WithFeatureFlags(feats ...string) StartOption
- func WithGlobalServiceName(enabled bool) StartOption
- func WithGlobalTag(k string, v interface{}) StartOption
- func WithHTTPClient(client *http.Client) StartOption
- func WithHTTPRoundTripper(r http.RoundTripper) StartOption
- func WithHeaderTags(headerAsTags []string) StartOption
- func WithHostname(name string) StartOption
- func WithLambdaMode(enabled bool) StartOption
- func WithLogStartup(enabled bool) StartOption
- func WithLogger(logger ddtrace.Logger) StartOption
- func WithOrchestrion(metadata map[string]string) StartOption
- func WithPartialFlushing(numSpans int) StartOption
- func WithPeerServiceDefaults(enabled bool) StartOption
- func WithPeerServiceMapping(from, to string) StartOption
- func WithPrioritySampling() StartOption
- func WithProfilerCodeHotspots(enabled bool) StartOption
- func WithProfilerEndpoints(enabled bool) StartOption
- func WithPropagator(p Propagator) StartOption
- func WithRuntimeMetrics() StartOption
- func WithSampler(s Sampler) StartOption
- func WithSamplingRules(rules []SamplingRule) StartOption
- func WithSendRetries(retries int) StartOption
- func WithService(name string) StartOption
- func WithServiceMapping(from, to string) StartOption
- func WithServiceName(name string) StartOption
- func WithServiceVersion(version string) StartOption
- func WithStatsComputation(enabled bool) StartOption
- func WithTraceEnabled(enabled bool) StartOption
- func WithUDS(socketPath string) StartOption
- func WithUniversalVersion(version string) StartOption
- type StartSpanOption
- func AnalyticsRate(rate float64) StartSpanOption
- func ChildOf(ctx ddtrace.SpanContext) StartSpanOption
- func Measured() StartSpanOption
- func ResourceName(name string) StartSpanOption
- func ServiceName(name string) StartSpanOption
- func SpanType(name string) StartSpanOption
- func StartTime(t time.Time) StartSpanOption
- func Tag(k string, v interface{}) StartSpanOption
- func WithSpanID(id uint64) StartSpanOption
- type TextMapCarrier
- type TextMapReader
- type TextMapWriter
- type UserMonitoringConfig
- type UserMonitoringOption
- func WithPropagation() UserMonitoringOption
- func WithUserEmail(email string) UserMonitoringOption
- func WithUserMetadata(key, value string) UserMonitoringOption
- func WithUserName(name string) UserMonitoringOption
- func WithUserRole(role string) UserMonitoringOption
- func WithUserScope(scope string) UserMonitoringOption
- func WithUserSessionID(sessionID string) UserMonitoringOption
Examples ¶
Constants ¶
const ( // SamplingRuleTrace specifies a sampling rule that applies to the entire trace if any spans satisfy the criteria. // If a sampling rule is of type SamplingRuleTrace, such rule determines the sampling rate to apply // to trace spans. If a span matches that rule, it will impact the trace sampling decision. SamplingRuleTrace = iota // SamplingRuleSpan specifies a sampling rule that applies to a single span without affecting the entire trace. // If a sampling rule is of type SamplingRuleSingleSpan, such rule determines the sampling rate to apply // to individual spans. If a span matches a rule, it will NOT impact the trace sampling decision. // In the case that a trace is dropped and thus not sent to the Agent, spans kept on account // of matching SamplingRuleSingleSpan rules must be conveyed separately. SamplingRuleSpan )
const ( // DefaultBaggageHeaderPrefix specifies the prefix that will be used in // HTTP headers or text maps to prefix baggage keys. DefaultBaggageHeaderPrefix = "ot-baggage-" // DefaultTraceIDHeader specifies the key that will be used in HTTP headers // or text maps to store the trace ID. DefaultTraceIDHeader = "x-datadog-trace-id" // DefaultParentIDHeader specifies the key that will be used in HTTP headers // or text maps to store the parent ID. DefaultParentIDHeader = "x-datadog-parent-id" // DefaultPriorityHeader specifies the key that will be used in HTTP headers // or text maps to store the sampling priority value. DefaultPriorityHeader = "x-datadog-sampling-priority" )
Variables ¶
var ( // ErrInvalidCarrier is returned when the carrier provided to the propagator // does not implement the correct interfaces. ErrInvalidCarrier = errors.New("invalid carrier") // ErrInvalidSpanContext is returned when the span context found in the // carrier is not of the expected type. ErrInvalidSpanContext = errors.New("invalid span context") // ErrSpanContextCorrupted is returned when there was a problem parsing // the information found in the carrier. ErrSpanContextCorrupted = errors.New("span context corrupted") // ErrSpanContextNotFound represents missing information in the given carrier. ErrSpanContextNotFound = errors.New("span context not found") )
Functions ¶
func ContextWithSpan ¶
ContextWithSpan returns a copy of the given context which includes the span s.
func Extract ¶
func Extract(carrier interface{}) (ddtrace.SpanContext, error)
Extract extracts a SpanContext from the carrier. The carrier is expected to implement TextMapReader, otherwise an error is returned. If the tracer is not started, calling this function is a no-op.
func Flush ¶
func Flush()
Flush flushes any buffered traces. Flush is in effect only if a tracer is started. Users do not have to call Flush in order to ensure that traces reach Datadog. It is a convenience method dedicated to a specific use case described below.
Flush is of use in Lambda environments, where starting and stopping the tracer on each invocation may create too much latency. In this scenario, a tracer may be started and stopped by the parent process whereas the invocation can make use of Flush to ensure any created spans reach the agent.
func Inject ¶
func Inject(ctx ddtrace.SpanContext, carrier interface{}) error
Inject injects the given SpanContext into the carrier. The carrier is expected to implement TextMapWriter, otherwise an error is returned. If the tracer is not started, calling this function is a no-op.
func MarkIntegrationImported ¶
MarkIntegrationImported labels the given integration as imported
func SetDataStreamsCheckpoint ¶
func SetDataStreamsCheckpoint(ctx context.Context, edgeTags ...string) (outCtx context.Context, ok bool)
SetDataStreamsCheckpoint sets a consume or produce checkpoint in a Data Streams pathway. This enables tracking data flow & end to end latency. To learn more about the data streams product, see: https://docs.datadoghq.com/data_streams/go/
func SetDataStreamsCheckpointWithParams ¶
func SetDataStreamsCheckpointWithParams(ctx context.Context, params options.CheckpointParams, edgeTags ...string) (outCtx context.Context, ok bool)
SetDataStreamsCheckpointWithParams sets a consume or produce checkpoint in a Data Streams pathway. This enables tracking data flow & end to end latency. To learn more about the data streams product, see: https://docs.datadoghq.com/data_streams/go/
func SetUser ¶
func SetUser(s Span, id string, opts ...UserMonitoringOption)
SetUser associates user information to the current trace which the provided span belongs to. The options can be used to tune which user bit of information gets monitored. In case of distributed traces, the user id can be propagated across traces using the WithPropagation() option. See https://docs.datadoghq.com/security_platform/application_security/setup_and_configure/?tab=set_user#add-user-information-to-traces
func Start ¶
func Start(opts ...StartOption) error
Start starts the tracer with the given set of options. It will stop and replace any running tracer, meaning that calling it several times will result in a restart of the tracer by replacing the current instance with a new one.
func TrackKafkaCommitOffset ¶
TrackKafkaCommitOffset should be used in the consumer, to track when it acks offset. if used together with TrackKafkaProduceOffset it can generate a Kafka lag in seconds metric.
func TrackKafkaProduceOffset ¶
TrackKafkaProduceOffset should be used in the producer, to track when it produces a message. if used together with TrackKafkaCommitOffset it can generate a Kafka lag in seconds metric.
Types ¶
type DBMPropagationMode ¶
type DBMPropagationMode string
DBMPropagationMode represents the mode of dbm propagation.
Note that enabling sql comment propagation results in potentially confidential data (service names) being stored in the databases which can then be accessed by other 3rd parties that have been granted access to the database.
const ( // DBMPropagationModeUndefined represents the dbm propagation mode not being set. This is the same as DBMPropagationModeDisabled. DBMPropagationModeUndefined DBMPropagationMode = "" // DBMPropagationModeDisabled represents the dbm propagation mode where all propagation is disabled. DBMPropagationModeDisabled DBMPropagationMode = "disabled" // DBMPropagationModeService represents the dbm propagation mode where only service tags (name, env, version) are propagated to dbm. DBMPropagationModeService DBMPropagationMode = "service" // DBMPropagationModeFull represents the dbm propagation mode where both service tags and tracing tags are propagated. Tracing tags include span id, trace id and the sampled flag. DBMPropagationModeFull DBMPropagationMode = "full" )
type FinishOption ¶
type FinishOption = ddtrace.FinishOption
FinishOption is a configuration option for FinishSpan. It is aliased in order to help godoc group all the functions returning it together. It is considered more correct to refer to it as the type as the origin, ddtrace.FinishOption.
func FinishTime ¶
func FinishTime(t time.Time) FinishOption
FinishTime sets the given time as the finishing time for the span. By default, the current time is used.
func NoDebugStack ¶
func NoDebugStack() FinishOption
NoDebugStack prevents any error presented using the WithError finishing option from generating a stack trace. This is useful in situations where errors are frequent and performance is critical.
func StackFrames ¶
func StackFrames(n, skip uint) FinishOption
StackFrames limits the number of stack frames included into erroneous spans to n, starting from skip.
func WithError ¶
func WithError(err error) FinishOption
WithError marks the span as having had an error. It uses the information from err to set tags such as the error message, error type and stack trace. It has no effect if the error is nil.
type HTTPHeadersCarrier ¶
HTTPHeadersCarrier wraps an http.Header as a TextMapWriter and TextMapReader, allowing it to be used using the provided Propagator implementation.
func (HTTPHeadersCarrier) ForeachKey ¶
func (c HTTPHeadersCarrier) ForeachKey(handler func(key, val string) error) error
ForeachKey implements TextMapReader.
func (HTTPHeadersCarrier) Set ¶
func (c HTTPHeadersCarrier) Set(key, val string)
Set implements TextMapWriter.
type Propagator ¶
type Propagator interface { // Inject takes the SpanContext and injects it into the carrier. Inject(context ddtrace.SpanContext, carrier interface{}) error // Extract returns the SpanContext from the given carrier. Extract(carrier interface{}) (ddtrace.SpanContext, error) }
Propagator implementations should be able to inject and extract SpanContexts into an implementation specific carrier.
func NewPropagator ¶
func NewPropagator(cfg *PropagatorConfig, propagators ...Propagator) Propagator
NewPropagator returns a new propagator which uses TextMap to inject and extract values. It propagates trace and span IDs and baggage. To use the defaults, nil may be provided in place of the config.
The inject and extract propagators are determined using environment variables with the following order of precedence:
- DD_TRACE_PROPAGATION_STYLE_INJECT
- DD_PROPAGATION_STYLE_INJECT (deprecated)
- DD_TRACE_PROPAGATION_STYLE (applies to both inject and extract)
- If none of the above, use default values
type PropagatorConfig ¶
type PropagatorConfig struct { // BaggagePrefix specifies the prefix that will be used to store baggage // items in a map. It defaults to DefaultBaggageHeaderPrefix. BaggagePrefix string // TraceHeader specifies the map key that will be used to store the trace ID. // It defaults to DefaultTraceIDHeader. TraceHeader string // ParentHeader specifies the map key that will be used to store the parent ID. // It defaults to DefaultParentIDHeader. ParentHeader string // PriorityHeader specifies the map key that will be used to store the sampling priority. // It defaults to DefaultPriorityHeader. PriorityHeader string // MaxTagsHeaderLen specifies the maximum length of trace tags header value. // It defaults to defaultMaxTagsHeaderLen, a value of 0 disables propagation of tags. MaxTagsHeaderLen int // B3 specifies if B3 headers should be added for trace propagation. // See https://github.com/openzipkin/b3-propagation B3 bool }
PropagatorConfig defines the configuration for initializing a propagator.
type RateSampler ¶
type RateSampler interface { Sampler // Rate returns the current sample rate. Rate() float64 // SetRate sets a new sample rate. SetRate(rate float64) }
RateSampler is a sampler implementation which randomly selects spans using a provided rate. For example, a rate of 0.75 will permit 75% of the spans. RateSampler implementations should be safe for concurrent use.
func NewAllSampler ¶
func NewAllSampler() RateSampler
NewAllSampler is a short-hand for NewRateSampler(1). It is all-permissive.
func NewRateSampler ¶
func NewRateSampler(rate float64) RateSampler
NewRateSampler returns an initialized RateSampler with a given sample rate.
type SQLCommentCarrier ¶
type SQLCommentCarrier struct { Query string Mode DBMPropagationMode DBServiceName string SpanID uint64 }
SQLCommentCarrier is a carrier implementation that injects a span context in a SQL query in the form of a sqlcommenter formatted comment prepended to the original query text. See https://google.github.io/sqlcommenter/spec/ for more details.
func (*SQLCommentCarrier) Extract ¶
func (c *SQLCommentCarrier) Extract() (ddtrace.SpanContext, error)
Extract parses for key value attributes in a sql query injected with trace information in order to build a span context
func (*SQLCommentCarrier) Inject ¶
func (c *SQLCommentCarrier) Inject(spanCtx ddtrace.SpanContext) error
Inject injects a span context in the carrier's Query field as a comment.
type SQLCommentInjectionMode
deprecated
type SQLCommentInjectionMode DBMPropagationMode
SQLCommentInjectionMode represents the mode of SQL comment injection.
Deprecated: Use DBMPropagationMode instead.
const ( // SQLInjectionUndefined represents the comment injection mode is not set. This is the same as SQLInjectionDisabled. SQLInjectionUndefined SQLCommentInjectionMode = SQLCommentInjectionMode(DBMPropagationModeUndefined) // SQLInjectionDisabled represents the comment injection mode where all injection is disabled. SQLInjectionDisabled SQLCommentInjectionMode = SQLCommentInjectionMode(DBMPropagationModeDisabled) // SQLInjectionModeService represents the comment injection mode where only service tags (name, env, version) are injected. SQLInjectionModeService SQLCommentInjectionMode = SQLCommentInjectionMode(DBMPropagationModeService) // SQLInjectionModeFull represents the comment injection mode where both service tags and tracing tags. Tracing tags include span id, trace id and sampling priority. SQLInjectionModeFull SQLCommentInjectionMode = SQLCommentInjectionMode(DBMPropagationModeFull) )
type Sampler ¶
type Sampler interface { // Sample returns true if the given span should be sampled. Sample(span Span) bool }
Sampler is the generic interface of any sampler. It must be safe for concurrent use.
type SamplingRule ¶
type SamplingRule struct { // Service specifies the regex pattern that a span service name must match. Service *regexp.Regexp // Name specifies the regex pattern that a span operation name must match. Name *regexp.Regexp // Rate specifies the sampling rate that should be applied to spans that match // service and/or name of the rule. Rate float64 // MaxPerSecond specifies max number of spans per second that can be sampled per the rule. // If not specified, the default is no limit. MaxPerSecond float64 // contains filtered or unexported fields }
SamplingRule is used for applying sampling rates to spans that match the service name, operation name or both. For basic usage, consider using the helper functions ServiceRule, NameRule, etc.
func NameRule ¶
func NameRule(name string, rate float64) SamplingRule
NameRule returns a SamplingRule that applies the provided sampling rate to spans that match the operation name provided.
func NameServiceRule ¶
func NameServiceRule(name string, service string, rate float64) SamplingRule
NameServiceRule returns a SamplingRule that applies the provided sampling rate to spans matching both the operation and service names provided.
func RateRule ¶
func RateRule(rate float64) SamplingRule
RateRule returns a SamplingRule that applies the provided sampling rate to all spans.
func ServiceRule ¶
func ServiceRule(service string, rate float64) SamplingRule
ServiceRule returns a SamplingRule that applies the provided sampling rate to spans that match the service name provided.
func SpanNameServiceMPSRule ¶
func SpanNameServiceMPSRule(name, service string, rate, limit float64) SamplingRule
SpanNameServiceMPSRule returns a SamplingRule of type SamplingRuleSpan that applies the provided sampling rate to all spans matching the operation and service name glob patterns up to the max number of spans per second that can be sampled. Operation and service fields must be valid glob patterns.
func SpanNameServiceRule ¶
func SpanNameServiceRule(name, service string, rate float64) SamplingRule
SpanNameServiceRule returns a SamplingRule of type SamplingRuleSpan that applies the provided sampling rate to all spans matching the operation and service name glob patterns provided. Operation and service fields must be valid glob patterns.
func (*SamplingRule) MarshalJSON ¶
func (sr *SamplingRule) MarshalJSON() ([]byte, error)
MarshalJSON implements the json.Marshaler interface.
type SamplingRuleType ¶
type SamplingRuleType int
SamplingRuleType represents a type of sampling rule spans are matched against.
func (SamplingRuleType) String ¶
func (sr SamplingRuleType) String() string
type Span ¶
Span is an alias for ddtrace.Span. It is here to allow godoc to group methods returning ddtrace.Span. It is recommended and is considered more correct to refer to this type as ddtrace.Span instead.
func SpanFromContext ¶
SpanFromContext returns the span contained in the given context. A second return value indicates if a span was found in the context. If no span is found, a no-op span is returned.
func StartSpan ¶
func StartSpan(operationName string, opts ...StartSpanOption) Span
StartSpan starts a new span with the given operation name and set of options. If the tracer is not started, calling this function is a no-op.
func StartSpanFromContext ¶
func StartSpanFromContext(ctx context.Context, operationName string, opts ...StartSpanOption) (Span, context.Context)
StartSpanFromContext returns a new span with the given operation name and options. If a span is found in the context, it will be used as the parent of the resulting span. If the ChildOf option is passed, it will only be used as the parent if there is no span found in `ctx`.
type StartOption ¶
type StartOption func(*config)
StartOption represents a function that can be provided as a parameter to Start.
func WithAgentAddr ¶
func WithAgentAddr(addr string) StartOption
WithAgentAddr sets the address where the agent is located. The default is localhost:8126. It should contain both host and port.
func WithAgentURL ¶
func WithAgentURL(agentURL string) StartOption
WithAgentURL sets the full trace agent URL
func WithAnalytics ¶
func WithAnalytics(on bool) StartOption
WithAnalytics allows specifying whether Trace Search & Analytics should be enabled for integrations.
func WithAnalyticsRate ¶
func WithAnalyticsRate(rate float64) StartOption
WithAnalyticsRate sets the global sampling rate for sampling APM events.
func WithDebugMode ¶
func WithDebugMode(enabled bool) StartOption
WithDebugMode enables debug mode on the tracer, resulting in more verbose logging.
func WithDebugSpansMode ¶
func WithDebugSpansMode(timeout time.Duration) StartOption
WithDebugSpansMode enables debugging old spans that may have been abandoned, which may prevent traces from being set to the Datadog Agent, especially if partial flushing is off. This setting can also be configured by setting DD_TRACE_DEBUG_ABANDONED_SPANS to true. The timeout will default to 10 minutes, unless overwritten by DD_TRACE_ABANDONED_SPAN_TIMEOUT. This feature is disabled by default. Turning on this debug mode may be expensive, so it should only be enabled for debugging purposes.
func WithDebugStack ¶
func WithDebugStack(enabled bool) StartOption
WithDebugStack can be used to globally enable or disable the collection of stack traces when spans finish with errors. It is enabled by default. This is a global version of the NoDebugStack FinishOption.
func WithDogstatsdAddress ¶
func WithDogstatsdAddress(addr string) StartOption
WithDogstatsdAddress specifies the address to connect to for sending metrics to the Datadog Agent. It should be a "host:port" string, or the path to a unix domain socket.If not set, it attempts to determine the address of the statsd service according to the following rules:
- Look for /var/run/datadog/dsd.socket and use it if present. IF NOT, continue to #2.
- The host is determined by DD_AGENT_HOST, and defaults to "localhost"
- The port is retrieved from the agent. If not present, it is determined by DD_DOGSTATSD_PORT, and defaults to 8125
This option is in effect when WithRuntimeMetrics is enabled.
func WithEnv ¶
func WithEnv(env string) StartOption
WithEnv sets the environment to which all traces started by the tracer will be submitted. The default value is the environment variable DD_ENV, if it is set.
func WithFeatureFlags ¶
func WithFeatureFlags(feats ...string) StartOption
WithFeatureFlags specifies a set of feature flags to enable. Please take into account that most, if not all features flags are considered to be experimental and result in unexpected bugs.
func WithGlobalServiceName ¶
func WithGlobalServiceName(enabled bool) StartOption
WithGlobalServiceName causes contrib libraries to use the global service name and not any locally defined service name. This is synonymous with `DD_TRACE_REMOVE_INTEGRATION_SERVICE_NAMES_ENABLED`.
func WithGlobalTag ¶
func WithGlobalTag(k string, v interface{}) StartOption
WithGlobalTag sets a key/value pair which will be set as a tag on all spans created by tracer. This option may be used multiple times.
func WithHTTPClient ¶
func WithHTTPClient(client *http.Client) StartOption
WithHTTPClient specifies the HTTP client to use when emitting spans to the agent.
func WithHTTPRoundTripper ¶
func WithHTTPRoundTripper(r http.RoundTripper) StartOption
WithHTTPRoundTripper is deprecated. Please consider using WithHTTPClient instead. The function allows customizing the underlying HTTP transport for emitting spans.
func WithHeaderTags ¶
func WithHeaderTags(headerAsTags []string) StartOption
WithHeaderTags enables the integration to attach HTTP request headers as span tags. Warning: Using this feature can risk exposing sensitive data such as authorization tokens to Datadog. Special headers can not be sub-selected. E.g., an entire Cookie header would be transmitted, without the ability to choose specific Cookies.
func WithHostname ¶
func WithHostname(name string) StartOption
WithHostname allows specifying the hostname with which to mark outgoing traces.
func WithLambdaMode ¶
func WithLambdaMode(enabled bool) StartOption
WithLambdaMode enables lambda mode on the tracer, for use with AWS Lambda. This option is only required if the the Datadog Lambda Extension is not running.
func WithLogStartup ¶
func WithLogStartup(enabled bool) StartOption
WithLogStartup allows enabling or disabling the startup log.
func WithLogger ¶
func WithLogger(logger ddtrace.Logger) StartOption
WithLogger sets logger as the tracer's error printer.
func WithOrchestrion ¶
func WithOrchestrion(metadata map[string]string) StartOption
WithOrchestrion configures Orchestrion's auto-instrumentation metadata. This option is only intended to be used by Orchestrion https://github.com/DataDog/orchestrion
func WithPartialFlushing ¶
func WithPartialFlushing(numSpans int) StartOption
WithPartialFlushing enables flushing of partially finished traces. This is done after "numSpans" have finished in a single local trace at which point all finished spans in that trace will be flushed, freeing up any memory they were consuming. This can also be configured by setting DD_TRACE_PARTIAL_FLUSH_ENABLED to true, which will default to 1000 spans unless overriden with DD_TRACE_PARTIAL_FLUSH_MIN_SPANS. Partial flushing is disabled by default.
func WithPeerServiceDefaults ¶
func WithPeerServiceDefaults(enabled bool) StartOption
WithPeerServiceDefaults sets default calculation for peer.service.
func WithPeerServiceMapping ¶
func WithPeerServiceMapping(from, to string) StartOption
WithPeerServiceMapping determines the value of the peer.service tag "from" to be renamed to service "to".
func WithPrioritySampling ¶
func WithPrioritySampling() StartOption
WithPrioritySampling is deprecated, and priority sampling is enabled by default. When using distributed tracing, the priority sampling value is propagated in order to get all the parts of a distributed trace sampled. To learn more about priority sampling, please visit: https://docs.datadoghq.com/tracing/getting_further/trace_sampling_and_storage/#priority-sampling-for-distributed-tracing
func WithProfilerCodeHotspots ¶
func WithProfilerCodeHotspots(enabled bool) StartOption
WithProfilerCodeHotspots enables the code hotspots integration between the tracer and profiler. This is done by automatically attaching pprof labels called "span id" and "local root span id" when new spans are created. You should not use these label names in your own code when this is enabled. The enabled value defaults to the value of the DD_PROFILING_CODE_HOTSPOTS_COLLECTION_ENABLED env variable or true.
func WithProfilerEndpoints ¶
func WithProfilerEndpoints(enabled bool) StartOption
WithProfilerEndpoints enables the endpoints integration between the tracer and profiler. This is done by automatically attaching a pprof label called "trace endpoint" holding the resource name of the top-level service span if its type is "http", "rpc" or "" (default). You should not use this label name in your own code when this is enabled. The enabled value defaults to the value of the DD_PROFILING_ENDPOINT_COLLECTION_ENABLED env variable or true.
func WithPropagator ¶
func WithPropagator(p Propagator) StartOption
WithPropagator sets an alternative propagator to be used by the tracer.
func WithRuntimeMetrics ¶
func WithRuntimeMetrics() StartOption
WithRuntimeMetrics enables automatic collection of runtime metrics every 10 seconds.
func WithSampler ¶
func WithSampler(s Sampler) StartOption
WithSampler sets the given sampler to be used with the tracer. By default an all-permissive sampler is used.
func WithSamplingRules ¶
func WithSamplingRules(rules []SamplingRule) StartOption
WithSamplingRules specifies the sampling rates to apply to spans based on the provided rules.
func WithSendRetries ¶
func WithSendRetries(retries int) StartOption
WithSendRetries enables re-sending payloads that are not successfully submitted to the agent. This will cause the tracer to retry the send at most `retries` times.
func WithService ¶
func WithService(name string) StartOption
WithService sets the default service name for the program.
func WithServiceMapping ¶
func WithServiceMapping(from, to string) StartOption
WithServiceMapping determines service "from" to be renamed to service "to". This option is is case sensitive and can be used multiple times.
func WithServiceName ¶
func WithServiceName(name string) StartOption
WithServiceName is deprecated. Please use WithService. If you are using an older version and you are upgrading from WithServiceName to WithService, please note that WithService will determine the service name of server and framework integrations.
func WithServiceVersion ¶
func WithServiceVersion(version string) StartOption
WithServiceVersion specifies the version of the service that is running. This will be included in spans from this service in the "version" tag, provided that span service name and config service name match. Do NOT use with WithUniversalVersion.
func WithStatsComputation ¶
func WithStatsComputation(enabled bool) StartOption
WithStatsComputation enables client-side stats computation, allowing the tracer to compute stats from traces. This can reduce network traffic to the Datadog Agent, and produce more accurate stats data. This can also be configured by setting DD_TRACE_STATS_COMPUTATION_ENABLED to true. Client-side stats is off by default.
func WithTraceEnabled ¶
func WithTraceEnabled(enabled bool) StartOption
WithTraceEnabled allows specifying whether tracing will be enabled
func WithUDS ¶
func WithUDS(socketPath string) StartOption
WithUDS configures the HTTP client to dial the Datadog Agent via the specified Unix Domain Socket path.
func WithUniversalVersion ¶
func WithUniversalVersion(version string) StartOption
WithUniversalVersion specifies the version of the service that is running, and will be applied to all spans, regardless of whether span service name and config service name match. See: WithService, WithServiceVersion. Do NOT use with WithServiceVersion.
type StartSpanOption ¶
type StartSpanOption = ddtrace.StartSpanOption
StartSpanOption is a configuration option for StartSpan. It is aliased in order to help godoc group all the functions returning it together. It is considered more correct to refer to it as the type as the origin, ddtrace.StartSpanOption.
func AnalyticsRate ¶
func AnalyticsRate(rate float64) StartSpanOption
AnalyticsRate sets a custom analytics rate for a span. It decides the percentage of events that will be picked up by the App Analytics product. It's represents a float64 between 0 and 1 where 0.5 would represent 50% of events.
func ChildOf ¶
func ChildOf(ctx ddtrace.SpanContext) StartSpanOption
ChildOf tells StartSpan to use the given span context as a parent for the created span.
func Measured ¶
func Measured() StartSpanOption
Measured marks this span to be measured for metrics and stats calculations.
func ResourceName ¶
func ResourceName(name string) StartSpanOption
ResourceName sets the given resource name on the started span. A resource could be an SQL query, a URL, an RPC method or something else.
func ServiceName ¶
func ServiceName(name string) StartSpanOption
ServiceName sets the given service name on the started span. For example "http.server".
func SpanType ¶
func SpanType(name string) StartSpanOption
SpanType sets the given span type on the started span. Some examples in the case of the Datadog APM product could be "web", "db" or "cache".
func StartTime ¶
func StartTime(t time.Time) StartSpanOption
StartTime sets a custom time as the start time for the created span. By default a span is started using the creation time.
func Tag ¶
func Tag(k string, v interface{}) StartSpanOption
Tag sets the given key/value pair as a tag on the started Span.
func WithSpanID ¶
func WithSpanID(id uint64) StartSpanOption
WithSpanID sets the SpanID on the started span, instead of using a random number. If there is no parent Span (eg from ChildOf), then the TraceID will also be set to the value given here.
type TextMapCarrier ¶
TextMapCarrier allows the use of a regular map[string]string as both TextMapWriter and TextMapReader, making it compatible with the provided Propagator.
func (TextMapCarrier) ForeachKey ¶
func (c TextMapCarrier) ForeachKey(handler func(key, val string) error) error
ForeachKey conforms to the TextMapReader interface.
func (TextMapCarrier) Set ¶
func (c TextMapCarrier) Set(key, val string)
Set implements TextMapWriter.
type TextMapReader ¶
type TextMapReader interface { // ForeachKey iterates over all keys that exist in the underlying // carrier. It takes a callback function which will be called // using all key/value pairs as arguments. ForeachKey will return // the first error returned by the handler. ForeachKey(handler func(key, val string) error) error }
TextMapReader allows iterating over sets of key/value pairs. Carriers implementing TextMapReader are compatible to be used with Datadog's TextMapPropagator.
type TextMapWriter ¶
type TextMapWriter interface { // Set sets the given key/value pair. Set(key, val string) }
TextMapWriter allows setting key/value pairs of strings on the underlying data structure. Carriers implementing TextMapWriter are compatible to be used with Datadog's TextMapPropagator.
type UserMonitoringConfig ¶
type UserMonitoringConfig struct { PropagateID bool Email string Name string Role string SessionID string Scope string Metadata map[string]string }
UserMonitoringConfig is used to configure what is used to identify a user. This configuration can be set by combining one or several UserMonitoringOption with a call to SetUser().
type UserMonitoringOption ¶
type UserMonitoringOption func(*UserMonitoringConfig)
UserMonitoringOption represents a function that can be provided as a parameter to SetUser.
func WithPropagation ¶
func WithPropagation() UserMonitoringOption
WithPropagation returns the option allowing the user id to be propagated through distributed traces. The user id is base64 encoded and added to the datadog propagated tags header. This option should only be used if you are certain that the user id passed to `SetUser()` does not contain any personal identifiable information or any kind of sensitive data, as it will be leaked to other services.
func WithUserEmail ¶
func WithUserEmail(email string) UserMonitoringOption
WithUserEmail returns the option setting the email of the authenticated user.
func WithUserMetadata ¶
func WithUserMetadata(key, value string) UserMonitoringOption
WithUserMetadata returns the option setting additional metadata of the authenticated user. This can be used multiple times and the given data will be tracked as `usr.{key}=value`.
func WithUserName ¶
func WithUserName(name string) UserMonitoringOption
WithUserName returns the option setting the name of the authenticated user.
func WithUserRole ¶
func WithUserRole(role string) UserMonitoringOption
WithUserRole returns the option setting the role of the authenticated user.
func WithUserScope ¶
func WithUserScope(scope string) UserMonitoringOption
WithUserScope returns the option setting the scope (authorizations) of the authenticated user.
func WithUserSessionID ¶
func WithUserSessionID(sessionID string) UserMonitoringOption
WithUserSessionID returns the option setting the session ID of the authenticated user.
Source Files ¶
- abandonedspans.go
- context.go
- data_streams.go
- doc.go
- dynamic_config.go
- log.go
- metrics.go
- option.go
- payload.go
- propagating_tags.go
- propagator.go
- rand.go
- remote_config.go
- rules_sampler.go
- sampler.go
- span.go
- span_msgp.go
- spancontext.go
- sqlcomment.go
- stats.go
- stats_payload.go
- stats_payload_msgp.go
- telemetry.go
- textmap.go
- time.go
- tracer.go
- transport.go
- util.go
- writer.go