Tracing

Last modified: September 18, 2025

Introduction

Mendix now supports tracing via OpenTelemetry. When tracing is enabled the runtime will generate traces that will help you analyze errors and performance. These traces can be sent to observability tools like Jaeger or Datadog.

Generated spans

The runtime generates spans for:

  • Runtime operations coming from the front end, for example microflow calls, retrieves, commits, and deletes
  • Microflow execution within the runtime, including sub-microflow calls
  • Microflow loops and loop iterations
  • Execution of task queue tasks

Configuration

Minimal Configuration

Tracing can be enabled from the App Settings -> Configuration dialog. In the Tracing tab you can enable tracing and specify an Endpoint and Service Name.

Testing

To test the tracing you can use Jaeger. For example, the all-in-one binary or docker image. Jaeger will listen to the above endpoint by default.

Alternatively you can set up the OpenTelemetry collector, which will also listen to the default endpoint and can be configured to send to backends which support OpenTelemetry. Check with your APM vendor to confirm that OpenTelemetry is supported. The free online collector configuration tool OTelBin can help with collector configuration.

All settings

Below we list the ones that are supported by the Mendix runtime. See Configure the SDK for a reference on the settings that are prefixed with otel..

The Java Agent can be configured through system properties, which can be added to the Extra JVM parameters field (for example, -Dotel.exporter.otlp.traces.endpoint), or set through environment variables.

Name Description Default
otel.service.name The name of the service. runtimelauncher
otel.resource.attributes Extra resource attributes to include in every span. Example: attribute1=value1,attribute2=value2
otel.traces.exporter Comma-separated list of span exporters. Supported values are: otlp, console, logging-otlp, and none. otlp
otel.exporter.otlp.traces.protocol The transport protocol to use on OTLP trace requests. Options include grpc and http/protobuf. http/protobuf (Java Agent)
otel.exporter.otlp.traces.endpoint The endpoint to send all OTLP traces to. It must be a URL with a scheme of either http or https based on the use of TLS. http://localhost:4318/v1/traces when the protocol is http/protobuf
http://localhost:4317 when the protocol is grpc
otel.exporter.otlp.traces.certificate The path to the file containing trusted certificates to use when verifying a trace server's TLS credentials. The file should contain one or more X.509 certificates in PEM format. By default the host platform's trusted root certificates are used.
otel.exporter.otlp.traces.client.key The path to the file containing the private client key to use when verifying a trace client's TLS credentials. The file should contain one private key in PKCS8 PEM format. By default no client key file is used.
otel.exporter.otlp.traces.client.certificate The path to the file containing trusted certificates to use when verifying a trace client's TLS credentials. The file should contain one or more X.509 certificates in PEM format. By default no certificate file is used.
mendix.tracing.max.microflow.depth Specifies the maximum nesting level of microflow calls for which the system will generate tracing spans. Introduced in Mendix 11.2.0. 10
mendix.tracing.max.loop.iteration Defines the maximum number of loop iterations for which individual tracing spans will be generated within a single microflow loop. Introduced in Mendix 11.2.0. 10

Enabling Tracing for Deployed Applications

To enable tracing for your deployed Mendix application, configure the following JVM parameters:

-javaagent:mxinstallation/runtime/agents/opentelemetry-javaagent.jar
-Dotel.javaagent.extensions=mxinstallation/runtime/agents/mendix-opentelemetry-agent-extension.jar
-Dotel.service.name=MyServiceName

OpenTelemetry Collector on Different Host

If the OpenTelemetry Collector is not running on the same host as your application, you must also specify the trace export endpoint:

-Dotel.exporter.otlp.traces.endpoint=http://collector-host:port

Docker-Based Deployment

For Docker deployments, you can set the JVM parameters using the JAVA_TOOL_OPTIONS environment variable. For example:

docker run MyMendixApp \
  -e JAVA_TOOL_OPTIONS="-javaagent:mxinstallation/runtime/agents/opentelemetry-javaagent.jar \
  -Dotel.javaagent.extensions=mxinstallation/runtime/agents/mendix-opentelemetry-agent-extension.jar \
  -Dotel.service.name=MyServiceName \
  -Dotel.exporter.otlp.traces.endpoint=http://collector-host:port"