Before You Begin
Before you can set up automatic instrumentation for your Python application, you will need to do a few things.Prepare Your Development Environment
To complete the required steps, you will need:- A working Python environment
- An application written in Python
Get Your Honeycomb API Key
To send data to Honeycomb, you’ll need to sign up for a free Honeycomb account and create a Honeycomb Ingest API Key. To get started, you can create a key that you expect to swap out when you deploy to production. Name it something helpful, perhaps noting that it’s a getting started key. Make note of your API key; for security reasons, you will not be able to see the key again, and you will need it later! If you want to use an API key you previously stored in a secure location, you can also look up details for Honeycomb API Keys any time in your Environment Settings, and use them to retrieve keys from your storage location.Add Automatic Instrumentation
Automatic instrumentation is provided by an agent, a command line toolopentelemetry-instrument that is used to run your application.
Add additional instrumentation to your application manually using the included OpenTelemetry Python SDK.
Acquire Dependencies
To add instrumentation, you should install required OpenTelemetry packages and instrumentation libraries.- pip
- poetry
-
Install the OpenTelemetry Python packages:
-
Install instrumentation libraries for the packages used by your application.
We recommend using the
opentelemetry-bootstraptool that comes with the OpenTelemetry SDK to scan your application packages and print out a list of available instrumentation libraries. You should then add these libraries to yourrequirements.txtfile:If you do not use arequirements.txtfile, you can install the libraries directly in your current environment:
Configure the OpenTelemetry SDK
Use environment variables to configure the OpenTelemetry SDK:| Variable | Description |
|---|---|
OTEL_SERVICE_NAME | Service name. When you send data, Honeycomb creates a dataset in which to store your data and uses this as the name. Can be any string. |
OTEL_EXPORTER_OTLP_PROTOCOL | The data format that the SDK uses to send telemetry to Honeycomb. For more on data format configuration options, read Choosing between gRPC and HTTP. |
OTEL_EXPORTER_OTLP_ENDPOINT | Honeycomb endpoint to which you want to send your data. |
OTEL_EXPORTER_OTLP_HEADERS | Adds your Honeycomb API Key to the exported telemetry headers for authorization. Learn how to find your Honeycomb API Key. |
OTEL_PYTHON_LOGGING_AUTO_INSTRUMENTATION_ENABLED | Enable logs auto-instrumentation using Python root logger. |
If you use Honeycomb Classic, you must also specify the Dataset using the
x-honeycomb-dataset header.Run Your Application
To see traces for your application, run your application using the OpenTelemetry Python automatic instrumentation toolopentelemetry-instrument, which configures the OpenTelemetry SDK:
YOUR_APPLICATION_NAME with the name of your application’s main file.
In Honeycomb’s UI, you should now see your application’s incoming requests and outgoing HTTP calls generate traces.
Add Custom Instrumentation
Automatic instrumentation is the easiest way to get started with instrumenting your code. To get additional insight into your system, you should also add custom, or manual, instrumentation where appropriate. Follow the instructions below to add custom instrumentation to your code. To learn more about custom, or manual, instrumentation, visit the comprehensive set of topics covered by Manual Instrumentation for Python in OpenTelemetry’s documentation.Acquire Dependencies
To start adding custom instrumentation, ensure that theopentelemetry-api package exists as a direct dependency in your project.
This package provides access to the high-level instrumentation APIs, which gives the ability to retrieve the current span to enrich with additional attributes, to create new spans, and to generate metrics.
Add Attributes to Spans
Adding context to a currently executing span in a trace can be useful. For example, you may have an application or service that handles users, and you want to associate the user with the span when querying your dataset in Honeycomb. To do this, get the current span from the context and set an attribute with the user ID:Acquire a Tracer
To create spans, you need to acquire aTracer.
Tracer, OpenTelemetry requires you to give it a name as a string.
This string is the only required parameter.
When traces are sent to Honeycomb, the name of the Tracer is turned into the library.name field, which can be used to show all spans created from a particular tracer.
In general, pick a name that matches the appropriate scope for your traces.
If you have one tracer for each service, then use the service name.
If you have multiple tracers that live in different “layers” of your application, then use the name that corresponds to that “layer”.
The library.name field is also used with traces created from instrumentation libraries.
Create Spans
To get the full picture of what is happening, you can leverage manual instrumentation to create custom spans that describe what is happening in your application. To do this, create or re-use aTracer instance and start a span.
Creating Spans Around Methods
You can use a decorator to wrap the execution of a method with a span. The span will be automatically closed once the method has completed.Add Multi-Span Attributes
Sometimes you want to add the same attribute to many spans within the same trace. This attribute may include variables calculated during your program, or other useful values for correlation or debugging purposes. To add this attribute, leverage the OpenTelemetry concept of baggage. Baggage allows you to add akey with a value as an attribute to every subsequent child span of the current application context.
In Python, baggage is configured as part of the OpenTelemetry trace context.
Modifications to the trace context must be both attached and detached when no longer used to make sure context state is disposed of correctly.
-
Install the
opentelemetry-processor-baggagepackage: -
Configure the OpenTelemetry SDK tracer provider to add a
BaggageSpanProcessor: -
Add a baggage entry for the current trace. For example,add a user ID attribute to multiple spans in a trace.
If you do not detach a modified trace context, you will see runtime errors as the OpenTelemetry SDK will detect un-detached contexts in its internal stack.Any Baggage attributes that you set in your application will be attached to outgoing network requests as a header. If your service communicates to a third party API, do NOT put sensitive information in the Baggage attributes.
Sampling
You can configure the OpenTelemetry SDK to sample the data it generates. Honeycomb weights sampled data based on sample rate, so you must set a resource attribute containing the sample rate. Use aTraceIdRatioBased sampler, with a ratio expressed as 1/N.
Then, also create a resource attribute called SampleRate with the value of N.
This allows Honeycomb to reweigh scalar values, like counts, so that they are accurate even with sampled data.
In the example below, our goal is to keep approximately half (1/2) of the data volume.
The resource attribute contains the denominator (2), while the OpenTelemetry sampler argument contains the decimal value (0.5).
SampleRate must be a positive integer.
Choosing between gRPC and HTTP
Most OpenTelemetry SDKs have an option to export telemetry as OTLP either over gRPC or HTTP/protobuf, with some also offering HTTP/JSON. If you are trying to choose between gRPC and HTTP, keep in mind:- Some SDKs default to using gRPC, and it may be easiest to start with the default option.
- Some firewall policies are not set up to handle gRPC and require using HTTP.
- gRPC may improve performance, but its long-lived connections may cause problems with load balancing, especially when using Refinery.