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