OpenTelemetry

OpenTelemetry is a vendor agnostic, open source standard for collecting telemetry data (metrics, logs, and traces).

DevCycle's OpenTelemetry integration allows you to send feature flag evaluation spans to your OpenTelemetry instance as part of the traces. This allows you to correlate feature flag states with other service monitoring data, making it easier to investigate and resolve issues. This integration is supported with the following SDKs:

• .NET
• Java

If you require support for a different SDK, please contact us at [email protected].

Send Flag Evaluations from Your App

To capture flag evaluations in OpenTelemetry traces, DevCycle SDKs now support Evaluation Hooks.

Ensure you're using a supported SDK version:

dotnet DevCycle.SDK.Server.Local 4.8.1
java com.devcycle:java-server-sdk:2.9.0
python devcycle-python-server-sdk 3.13.0
go github.com/devcyclehq/go-server-sdk/v2 2.24.0
js @devcycle/nodejs-server-sdk 1.55.0
ruby devcycle-ruby-server-sdk 3.6.2

We provide ready-made integration hooks in this repo (DevCycle Integration Hooks for you to copy into your codebase.

To enable collecting feature flag evaluations in the SDK, you will have to call the client's addHook method and pass in the hook to it.

Example: Add Hook in Java

   // Create DevCycle client with default options
    devCycleClient = new DevCycleLocalClient(devCycleServerSdkKey);

    // Add OpenTelemetrySpanHook for all variable types
    OpenTelemetrySpanHook hook = new OpenTelemetrySpanHook();
    devCycleClient.addHook(hook);

Example: Add Hook in C#

// Initialize DevCycle client with standard configuration
DevCycleLocalClient client = new DevCycleLocalClientBuilder()
    .SetSDKKey("<DEVCYCLE_SERVER_SDK_KEY>")
    .SetLogger(LoggerFactory.Create(builder => builder.AddConsole()))
    .Build();

// Initialize evaluation hook with an ActivitySource for tracing
client.AddEvalHook(new OpenTelemetrySpanHook(new ActivitySource("DevCycle.FlagEvaluations")));

When enabled, feature flag evaluations generate spans named: feature_flag_evaluation.{variable_key} which will have the attributes for the evaluation. There are following attributes added for each evaluation:

Attribute	Type	Description
feature_flag.key	string	The key of the variable that was evaluated.
feature_flag.provider.name	string	The name of the provider that was used to evaluate the feature flag. (devcycle)
feature_flag.context.id	string	The id of the user that was used to evaluate the feature flag.
feature_flag.value_type	string	The type of the value that was evaluated.
feature_flag.project	string	The project that the variable belongs to.
feature_flag.environment	string	The environment that the variable belongs to.
feature_flag.set.id	string	The feature that the evalluated variable belongs to.
feature_flag.url	string	DevCycle URL of the feature.
feature_flag.result.value	string	The value that was evaluated.
feature_flag.result.reason	string	The reason for the evaluation.
feature_flag.result.reason.details	string	The details of the evaluation.

info

Not all SDKs support all of the attributes, you may be missing some of the attributes depending on the SDK you are using. Refer to the SDK documentation for more information.