Distributed app tracing implementation in pure scala using cats-effect
MIT License
⚠️ If you are upgrading to
0.14.0
please read the migration guide.
Yet another distributed tracing system, this time just for Scala. Heavily relies upon Cats and Cats Effect.
Compatible with OpenTelemetry and Jaeger, based on, and interoperates with Natchez.
0.14.0
It increasingly seems that Java tracing libraries are dependent on gRPC, which usually brings along lots of other dependencies. You may find Trace4Cats useful if you want to...
native-image
using GraalVM
Trace4Cats supports publishing spans to the following systems:
Instrumentation for trace propagation and continuation is available for the following libraries:
Unlike other tracing libraries, trace attributes are lazily evaluated. If a span is not sampled, no computation associated with calculating attribute values will be performed.
More information on how to use these can be found in the examples documentation.
For more see the documentation and more advanced examples.
Add the following dependencies to your build.sbt
:
"io.janstenpickle" %% "trace4cats-core" % "0.14.0"
"io.janstenpickle" %% "trace4cats-avro-exporter" % "0.14.0"
Then run the collector in span logging mode:
echo "log-spans: true" > /tmp/collector.yaml
docker run -p7777:7777 -p7777:7777/udp -it \
-v /tmp/collector.yaml:/tmp/collector.yaml \
janstenpickle/trace4cats-collector-lite:0.14.0 \
--config-file=/tmp/collector.yaml
Finally, run the following code to export some spans to the collector:
import cats.Monad
import cats.data.Kleisli
import cats.effect._
import cats.effect.std.Console
import cats.implicits._
import trace4cats._
import trace4cats.avro.AvroSpanCompleter
import scala.concurrent.duration._
object Trace4CatsQuickStart extends IOApp.Simple {
def entryPoint[F[_]: Async](process: TraceProcess): Resource[F, EntryPoint[F]] =
AvroSpanCompleter.udp[F](process, config = CompleterConfig(batchTimeout = 50.millis)).map { completer =>
EntryPoint[F](SpanSampler.always[F], completer)
}
def runF[F[_]: Monad: Console: Trace]: F[Unit] =
for {
_ <- Trace[F].span("span1")(Console[F].println("trace this operation"))
_ <- Trace[F].span("span2", SpanKind.Client)(Console[F].println("send some request"))
_ <- Trace[F].span("span3", SpanKind.Client)(
Trace[F].putAll("attribute1" -> "test", "attribute2" -> 200) >>
Trace[F].setStatus(SpanStatus.Cancelled)
)
} yield ()
def run: IO[Unit] =
entryPoint[IO](TraceProcess("trace4cats")).use { ep =>
ep.root("this is the root span").use { span =>
runF[Kleisli[IO, Span[IO], *]].run(span)
}
}
}
0.14.0
Version 0.14.0
introduced a reworked module and package structure that reduced the number of dependencies and imports
required to get started quickly. Effectively import trace4cats._
is all you should need to import throughout most of
your codebase.
See the migration guide for information on how to migrate.
Trace4Cats is separated into a few repositories:
trace4cats-avro
Avro codecs, TCP/UDP server and exportertrace4cats-avro-kafka
Avro Kafka exporter and consumertrace4cats-cloudtrace
Google Cloud Trace exporterstrace4cats-components
standalone Trace4Catstrace4cats-datadog
Datadog exporterstrace4cats-docs
documentation and examplestrace4cats-dynamic-extras
extra utilities for dynamicallytrace4cats-exporter-http
HTTP span exportertrace4cats-http4s
Http4s client and server integrationstrace4cats-jaeger
Jaeger exporterstrace4cats-jaeger-integration-test
Integrationtrace4cats-kafka
FS2 Kafka integrationstrace4cats-natchez
Natchez integrationstrace4cats-newrelic
New Relic exporterstrace4cats-opentelemetry
OpenTelemetry exporterstrace4cats-sttp
Sttp client and Tapir integrationstrace4cats-tail-sampling-extras
extra utilities fortrace4cats-zipkin
Zipkin exporterstrace4cats-zio
ZIO implementations of Trace4Cats typeclassesTrace4Cats is made up as both a set of libraries for integration in applications and standalone processes. For information on the libraries and interfaces see the design documentation.
The standalone components are the agent and the collector. To see how they work together, see the topologies documentation, for information on configuring and running the agent and collector see the components documentation.
The source code for these components is located in the
trace4cats-components
repository.
To use Trace4Cats within your application add the dependencies listed below as needed:
"io.janstenpickle" %% "trace4cats-core" % "0.14.0"
"io.janstenpickle" %% "trace4cats-rate-sampling" % "0.14.0"
"io.janstenpickle" %% "trace4cats-fs2" % "0.14.0"
"io.janstenpickle" %% "trace4cats-http4s-client" % "0.14.0"
"io.janstenpickle" %% "trace4cats-http4s-server" % "0.14.0"
"io.janstenpickle" %% "trace4cats-sttp-client3" % "0.14.0"
"io.janstenpickle" %% "trace4cats-sttp-tapir" % "0.14.0"
"io.janstenpickle" %% "trace4cats-natchez" % "0.14.0"
"io.janstenpickle" %% "trace4cats-avro-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-avro-kafka-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-avro-kafka-consumer" % "0.14.0"
"io.janstenpickle" %% "trace4cats-jaeger-thrift-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-opentelemetry-otlp-grpc-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-opentelemetry-otlp-http-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-opentelemetry-jaeger-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-stackdriver-grpc-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-stackdriver-http-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-datadog-http-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-newrelic-http-exporter" % "0.14.0"
"io.janstenpickle" %% "trace4cats-zipkin-http-exporter" % "0.14.0"
native-image
CompatibilityThe following span completers have been found to be compatible with native-image
:
This project supports the Scala Code of Conduct and aims that its channels (mailing list, Gitter, github, etc.) to be welcoming environments for everyone.