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Girish Kumare48ec8a2020-08-18 12:28:51 +00001// Copyright (c) 2017 Uber Technologies, Inc.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package jaeger
16
17import (
18 "time"
19
20 "github.com/uber/jaeger-client-go/log"
21)
22
23// SamplerOption is a function that sets some option on the sampler
24type SamplerOption func(options *samplerOptions)
25
26// SamplerOptions is a factory for all available SamplerOption's.
27var SamplerOptions SamplerOptionsFactory
28
29// SamplerOptionsFactory is a factory for all available SamplerOption's.
30// The type acts as a namespace for factory functions. It is public to
31// make the functions discoverable via godoc. Recommended to be used
32// via global SamplerOptions variable.
33type SamplerOptionsFactory struct{}
34
35type samplerOptions struct {
36 metrics *Metrics
37 sampler SamplerV2
38 logger log.DebugLogger
39 samplingServerURL string
40 samplingRefreshInterval time.Duration
41 samplingFetcher SamplingStrategyFetcher
42 samplingParser SamplingStrategyParser
43 updaters []SamplerUpdater
44 posParams PerOperationSamplerParams
45}
46
47// Metrics creates a SamplerOption that initializes Metrics on the sampler,
48// which is used to emit statistics.
49func (SamplerOptionsFactory) Metrics(m *Metrics) SamplerOption {
50 return func(o *samplerOptions) {
51 o.metrics = m
52 }
53}
54
55// MaxOperations creates a SamplerOption that sets the maximum number of
56// operations the sampler will keep track of.
57func (SamplerOptionsFactory) MaxOperations(maxOperations int) SamplerOption {
58 return func(o *samplerOptions) {
59 o.posParams.MaxOperations = maxOperations
60 }
61}
62
63// OperationNameLateBinding creates a SamplerOption that sets the respective
64// field in the PerOperationSamplerParams.
65func (SamplerOptionsFactory) OperationNameLateBinding(enable bool) SamplerOption {
66 return func(o *samplerOptions) {
67 o.posParams.OperationNameLateBinding = enable
68 }
69}
70
71// InitialSampler creates a SamplerOption that sets the initial sampler
72// to use before a remote sampler is created and used.
73func (SamplerOptionsFactory) InitialSampler(sampler Sampler) SamplerOption {
74 return func(o *samplerOptions) {
75 o.sampler = samplerV1toV2(sampler)
76 }
77}
78
79// Logger creates a SamplerOption that sets the logger used by the sampler.
80func (SamplerOptionsFactory) Logger(logger Logger) SamplerOption {
81 return func(o *samplerOptions) {
82 o.logger = log.DebugLogAdapter(logger)
83 }
84}
85
86// SamplingServerURL creates a SamplerOption that sets the sampling server url
87// of the local agent that contains the sampling strategies.
88func (SamplerOptionsFactory) SamplingServerURL(samplingServerURL string) SamplerOption {
89 return func(o *samplerOptions) {
90 o.samplingServerURL = samplingServerURL
91 }
92}
93
94// SamplingRefreshInterval creates a SamplerOption that sets how often the
95// sampler will poll local agent for the appropriate sampling strategy.
96func (SamplerOptionsFactory) SamplingRefreshInterval(samplingRefreshInterval time.Duration) SamplerOption {
97 return func(o *samplerOptions) {
98 o.samplingRefreshInterval = samplingRefreshInterval
99 }
100}
101
102// SamplingStrategyFetcher creates a SamplerOption that initializes sampling strategy fetcher.
103func (SamplerOptionsFactory) SamplingStrategyFetcher(fetcher SamplingStrategyFetcher) SamplerOption {
104 return func(o *samplerOptions) {
105 o.samplingFetcher = fetcher
106 }
107}
108
109// SamplingStrategyParser creates a SamplerOption that initializes sampling strategy parser.
110func (SamplerOptionsFactory) SamplingStrategyParser(parser SamplingStrategyParser) SamplerOption {
111 return func(o *samplerOptions) {
112 o.samplingParser = parser
113 }
114}
115
116// Updaters creates a SamplerOption that initializes sampler updaters.
117func (SamplerOptionsFactory) Updaters(updaters ...SamplerUpdater) SamplerOption {
118 return func(o *samplerOptions) {
119 o.updaters = updaters
120 }
121}
122
123func (o *samplerOptions) applyOptionsAndDefaults(opts ...SamplerOption) *samplerOptions {
124 for _, option := range opts {
125 option(o)
126 }
127 if o.sampler == nil {
128 o.sampler = newProbabilisticSampler(0.001)
129 }
130 if o.logger == nil {
131 o.logger = log.NullLogger
132 }
133 if o.samplingServerURL == "" {
134 o.samplingServerURL = DefaultSamplingServerURL
135 }
136 if o.metrics == nil {
137 o.metrics = NewNullMetrics()
138 }
139 if o.samplingRefreshInterval <= 0 {
140 o.samplingRefreshInterval = defaultSamplingRefreshInterval
141 }
142 if o.samplingFetcher == nil {
David K. Bainbridgebd6b2882021-08-26 13:31:02 +0000143 o.samplingFetcher = newHTTPSamplingStrategyFetcher(o.samplingServerURL, o.logger)
Girish Kumare48ec8a2020-08-18 12:28:51 +0000144 }
145 if o.samplingParser == nil {
146 o.samplingParser = new(samplingStrategyParser)
147 }
148 if o.updaters == nil {
149 o.updaters = []SamplerUpdater{
150 &AdaptiveSamplerUpdater{
151 MaxOperations: o.posParams.MaxOperations,
152 OperationNameLateBinding: o.posParams.OperationNameLateBinding,
153 },
154 new(ProbabilisticSamplerUpdater),
155 new(RateLimitingSamplerUpdater),
156 }
157 }
158 return o
159}