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Diffstat (limited to 'vendor/go.opencensus.io/trace/doc.go')
-rw-r--r-- | vendor/go.opencensus.io/trace/doc.go | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/trace/doc.go b/vendor/go.opencensus.io/trace/doc.go new file mode 100644 index 000000000..04b1ee4f3 --- /dev/null +++ b/vendor/go.opencensus.io/trace/doc.go @@ -0,0 +1,53 @@ +// Copyright 2017, OpenCensus Authors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +/* +Package trace contains support for OpenCensus distributed tracing. + +The following assumes a basic familiarity with OpenCensus concepts. +See http://opencensus.io + + +Exporting Traces + +To export collected tracing data, register at least one exporter. You can use +one of the provided exporters or write your own. + + trace.RegisterExporter(exporter) + +By default, traces will be sampled relatively rarely. To change the sampling +frequency for your entire program, call ApplyConfig. Use a ProbabilitySampler +to sample a subset of traces, or use AlwaysSample to collect a trace on every run: + + trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()}) + +Be careful about using trace.AlwaysSample in a production application with +significant traffic: a new trace will be started and exported for every request. + +Adding Spans to a Trace + +A trace consists of a tree of spans. In Go, the current span is carried in a +context.Context. + +It is common to want to capture all the activity of a function call in a span. For +this to work, the function must take a context.Context as a parameter. Add these two +lines to the top of the function: + + ctx, span := trace.StartSpan(ctx, "example.com/Run") + defer span.End() + +StartSpan will create a new top-level span if the context +doesn't contain another span, otherwise it will create a child span. +*/ +package trace // import "go.opencensus.io/trace" |