Moesif OpenTelemetry Integration

Integrate Moesif API Analytics with your OpenTelemetry-instrumented applications to gain deep insights into your API traffic and performance. This integration allows you to send trace data from your OpenTelemetry setup directly to Moesif without any code changes or redeployments.

How it works

The integration works by configuring your OpenTelemetry exporter to send trace data to Moesif using the OTLP/HTTP protocol. Moesif treats each OpenTelemetry HTTP Request/Response Span as an API event, capturing key information like request and response details, user identification, and metadata.

By integrating with OpenTelemetry, you can leverage existing distributed tracing to analyze API performance and user behavior across services and applications.

How to Install

Prerequisites

• An application instrumented with OpenTelemetry SDKs or an OpenTelemetry Collector which can export OTLP/HTTP.
• A Moesif account.

Steps

1. Configure the OpenTelemetry Exporter

   Set up your OpenTelemetry SDK to export trace data to Moesif using the OTLP/HTTP protocol.

   Example Configuration (YAML):

   exporters:
     otlphttp:
       endpoint: https://api.moesif.net/v1/traces
       headers:
         X-Moesif-Application-Id: 'Your Moesif Application ID'
   

   Example Configuration (Environment Variables):

   # Set the OTLP endpoint
   export OTEL_EXPORTER_OTLP_ENDPOINT=https://api.moesif.net/v1/traces
   
   # Include your Moesif Application ID in the headers
   export OTEL_EXPORTER_OTLP_HEADERS=X-Moesif-Application-Id=Your_Moesif_Application_ID
   

   Replace 'Your Moesif Application ID' with your actual Moesif Application ID. To get your Application ID:

   1. Log into Moesif Portal.
   2. Select the account icon to bring up the settings menu.
   3. Select Installation or API Keys.
   4. Copy your Moesif Application ID from the Collector Application ID field.

2. Set Up Authentication

   Ensure your Moesif Application ID is included in the request headers as X-Moesif-Application-Id to authenticate requests.

3. Run Your Application

   Start your application, and OpenTelemetry will begin sending trace data to Moesif.

Overview of Span Mapping

Moesif supports capturing HTTP request span data which follows the OpenTelemetry Semantic Conventions for HTTP Spans

Moesif maps OpenTelemetry spans to its API event model. Each span is treated as a single API event in Moesif with the addition of Trace ID, Span ID, Parent Span, Span Links, and metadata.

The HTTP semantic conventions for OpenTelemetry are recently stable. We do our best to be backward compatible with prior HTTP tracing implementations as well. To understand exactly how OpenTelemetry spans are mapped to Moesif API events, refer to the table below.

Span to Moesif API Event Mapping

OpenTelemetry Span Field	Moesif Field	Notes
trace_id	trace_id	Used to group spans into a single trace.
span_id	span.id	Unique identifier for the span.
parent_span_id	span.parent_id	Identifier of the parent span, if any.
name	action_name	Name of the span or the API action.
kind	direction	Mapped to incoming or outgoing based on span kind.
start_time_unix_nano	request.time	Start time of the request.
end_time_unix_nano	response.time	End time of the response.
attributes	Various fields (see below)	Attributes are mapped to Moesif fields and metadata.
status	span.status	Status of the span.

Span Attributes Mapping

OpenTelemetry span attributes are mapped to Moesif fields as follows:

Span Attribute Key	Moesif Field	Notes
http.method	request.verb	HTTP method (GET, POST, etc.).
http.url or url.full	request.uri	Full request URI.
http.status_code	response.status	HTTP response status code.
http.request.header.<key>	request.headers.<key>	Request headers.
http.response.header.<key>	response.headers.<key>	Response headers.
http.request.body	request.body	Request body string/bytes.
http.response.body	response.body	Response body string/bytes.
client.address or net.peer.ip	request.ip_address	Client IP address.
user_agent.original	request.user_agent_string	User agent string.
user.id	user_id	ID for the user.
company.id	company_id	ID for the company.
subscription.id	subscription_id	ID for the subscription.
weight	weight	Weight for sampling.

Custom Span Attributes

All other span attributes are stored in the metadata field in Moesif. You can use Span attributes to add custom metadata to your API events.

Body Capturing

Moesif now supports capturing request and response bodies from OpenTelemetry attributes. The bodies must be provided as raw strings or byte arrays.

To include request and response bodies:

• Set the http.request.body attribute on the span to the raw request body content.
• Set the http.response.body attribute on the span to the raw response body content.

Example (in Java):

Span.current().setAttribute("http.request.body", requestBodyStringOrBytes);
Span.current().setAttribute("http.response.body", responseBodyStringOrBytes);

Note:

• Only primitive string or byte values are supported. If necessary, ensure you convert any structured object to a string or byte array before setting these attributes.

Enabling User, Company, Subscription Tracking

These IDs are determined by your custom data, and are translated into the corresponding Moesif event fields for entity tracking. Associate API calls with companies by adding the relevant attribute to the span, user.id, company.id, or subscription.id.

Span.current().setAttribute("user.id", "user_123");

There are additional user and company tracking options available in Moesif. For more information, refer to the docs on Identifying Users

Weight Attribute / Sampling

If you are using OpenTelemetry’s sampling, you can set the weight attribute to an integer value that is the inverse of the sample rate to ensure Moesif metrics and counts reflect the correct scale. For example, if you are sampling 50% of requests, set weight = int(1.0 / 0.5) = 2 or 3 for 33% sampling and so on.

double sampleRate = 0.5;
int weight = int(1.0 / sampleRate);
Span.current().setAttribute("weight", weight);

see also:

• OpenTelemetry Sampling Documentation
• OpenTelemetry TraceIdRatioBased Sampler

Span Action Events

In addition to capturing main request/response spans, Moesif now supports capturing OpenTelemetry span events as separate span_action events. Span events are annotations or logs added to a span that provide deeper insights into what occurred during the operation represented by the span.

How It Works:

• Each event recorded on a span in OpenTelemetry is ingested into Moesif as a separate event of type span_action.
• These span_action events:
  • Contain the trace_id and span_id linking them to the main API event (the span).
  • Include a request.time corresponding to the event’s timestamp.
  • Store any span event attributes as metadata for detailed analysis.
• Unlike the primary api_call events, span_action events do not represent a full HTTP request/response. Instead, they provide supplemental details (e.g., internal logs, checkpoints, or custom annotations).

Example (in Java):

Span.current().addEvent("Database Query Start", Attributes.of(
  stringKey("db.query"), "SELECT * FROM users",
  stringKey("db.timing.notes"), "Cache miss"
));

Moesif will ingest this as a separate span_action event linked to the original trace and span. The key difference between a Span Event and an additional child Span is that the Span Event does not have a start_time or end_time and is not a full HTTP request/response. They represent a named action with a single time point and potentially distinct metadata within the Span itself. OpenTelemetry Span Events

Example Integrations

If you are using an OpenTelemetry Collector already, the integration will be as simple as including the exporter configuration above.

If you are instrumenting an application from scratch for OpenTelemetry tracing, we have an example Node JS application that demonstrates how to set up OpenTelemetry with Moesif. The example application is available at

Node JS Tracing Example on Github

Limitations

There are certain OpenTelemetry specific limitations to be aware of:

1. Traces and HTTP Spans, Only Traces, not OpenTelemetry Logs or Metrics, are supported. Within Traces, HTTP Spans are supported. Spans for other types of information cannot be ingested at this release. See OpenTelemetry Semantic Conventions for HTTP Spans
2. Governance Rules Are Not Supported, Moesif’s governance features, such as blocking or modifying API calls, are not supported through the OpenTelemetry integration.
3. Dynamic Sampling, Moesif’s dynamic sampling is not applied to data ingested via OpenTelemetry. Sampling must be configured manually within your OpenTelemetry tooling. If you do so, set the weight attribute as described above. See the OpenTelemetry Sampling Documentation

Troubleshooting

• Data Not Appearing in Moesif

  Ensure your OpenTelemetry exporter is correctly configured with the Moesif endpoint and Application ID and that your traces include HTTP spans.

• Authentication Errors

  Verify that the X-Moesif-Application-Id header is correctly set with your valid Moesif Application ID.

• Incomplete Data

  If certain fields are missing, check that you have correctly added custom span attributes where necessary.

Additional Resources

• Moesif Server Integrations
• OpenTelemetry Documentation
• Identifying Users and Companies
• OpenTelemetry Sampling Configuration

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