Jaeger Tracing

Jaeger Tracing

Helidon is integrated with the Jaeger tracer.

The Jaeger builder is loaded through ServiceLoader and configured. You could also use the Jaeger builder directly, though this would create a source-code dependency on the Jaeger tracer.

Maven Coordinates

To enable Jaeger Tracing add the following dependency to your project’s pom.xml (see Managing Dependencies).

<dependency>
    <groupId>io.helidon.tracing</groupId>
    <artifactId>helidon-tracing-jaeger</artifactId>
</dependency>

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Configuring Jaeger

The Jaeger tracer supports the following configuration options:

Key	Default value	Builder method	Description
service	N/A	serviceName	Name of the service, to distinguish traces crossing service boundaries; Jaeger is using lower-case only, name will be automatically lower-cased
protocol	http	collectorProtocol	Protocol of the Jaeger trace collector (`udp`, `http` or `https`), to switch to agent mode, use `udp`
host	localhost	collectorHost	Host of the Jaeger trace collector (IP Address, hostname, or FQDN)
port	14268	collectorPort	Port of the Jaeger trace collector
path	/api/traces	collectorPath	Path of the Jaeger trace collector
token	N/A	token	Authentication token to use (token authentication)
username	N/A	username	User to authenticate (basic authentication)
password	N/A	password	Password of the user to authenticate (basic authentication)
propagation	library default	addPropagation	Propagation type (`jaeger` or `b3`)
log-spans	library default	logSpans	Whether to log spans (boolean)
max-queue-size	library default	maxQueueSize	Maximal queue size of the reporter (int)
flush-interval-ms	library default	flushInterval	Reporter flush interval in milliseconds
sampler-type	library default	samplerType	Sampler type (`probabilistic`, `ratelimiting`, `remote`)
sampler-param	library default	samplerParam	Numeric parameter specifying details for the sampler type
sampler-manager	library default	samplerManager	Host and port of the sampler manager for `remote` type
enabled	true	enabled	If set to false, tracing would be disabled
tags	N/A	addTracerTag(String, String)	`String` tags to add to each span
boolean-tags	N/A	addTracerTag(String, boolean)	`boolean` tags to add to each span
int-tags	N/A	addTracerTag(String, int)	`int` tags to add to each span

The following is an example of a Jaeger configuration, specified in the YAML format.

tracing:
    service: "helidon-full-http"
    protocol: "https"     # JAEGER_ENDPOINT (if not udp, http is expected and endpoint is filled)
    host: "192.168.1.3"   # JAEGER_ENDPOINT
    port: 14240           # JAEGER_ENDPOINT
    path: "/api/traces/mine"   # JAEGER_ENDPOINT
    token: "token"        # JAEGER_AUTH_TOKEN
    # Either token or username/password
    #username:  "user"     # JAEGER_USER
    #password: "pass"      # JAEGER_PASSWORD
    propagation: "jaeger" # JAEGER_PROPAGATION either "jaeger" or "b3"
    log-spans: false      # JAEGER_REPORTER_LOG_SPANS
    max-queue-size: 42    # JAEGER_REPORTER_MAX_QUEUE_SIZE
    flush-interval-ms: 10001 # JAEGER_REPORTER_FLUSH_INTERVAL
    sampler-type: "remote"# JAEGER_SAMPLER_TYPE (https://www.jaegertracing.io/docs/latest/sampling/#client-sampling-configuration)
    sampler-param: 0.5    # JAEGER_SAMPLER_PARAM (number)
    sampler-manager: "localhost:47877" # JAEGER_SAMPLER_MANAGER_HOST_PORT
    tags:
      tag1: "tag1-value"  # JAEGER_TAGS
      tag2: "tag2-value"  # JAEGER_TAGS
    boolean-tags:
      tag3: true          # JAEGER_TAGS
      tag4: false         # JAEGER_TAGS
    int-tags:
      tag5: 145           # JAEGER_TAGS
      tag6: 741           # JAEGER_TAGS

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Integrating with Jaeger Tracing

Jaeger tracks its own behavior using metrics. See Metrics Support for Jaeger to read how to integrate Jaeger metrics with Helidon.