[BUG]: aws-sdk: Default service plugin never subscribes — services outside the known list (STS, Secrets Manager, …) produce no spans #10444

Tracer Version(s)

5.109.0 and 6.16.0 (reproduced on both)

Node.js Version(s)

24.14.0

Bug Report

AWS SDK v3 calls to any service that is not in the aws-sdk instrumentation's known list — e.g. STS AssumeRole / GetCallerIdentity, Secrets Manager GetSecretValue — never produce an aws.request span. Only the underlying http.request appears. SQS / SNS / S3 / DynamoDB etc. work as expected.

Cause: the instrumentation and the plugin disagree on which channel unknown services use.

• packages/datadog-instrumentations/src/aws-sdk.js — getChannelSuffix() returns 'default' for any service not in KNOWN_CHANNEL_SUFFIXES (or CHANNEL_SUFFIX_ALIASES), so wrapSmithySend publishes on apm:aws:request:start:default.
• packages/datadog-plugin-aws-sdk/src/services/default.js is class Default extends BaseAwsSdkPlugin {} with no static id, so it inherits the base class's static id = 'aws'.
• packages/datadog-plugin-aws-sdk/src/base.js — get serviceIdentifier() is this.constructor.id.toLowerCase(), and the constructor subscribes to apm:aws:request:start:${this.serviceIdentifier}. The Default plugin therefore subscribes to …:aws.

Nothing subscribes to …:default, so the publish goes nowhere. Confirmed at runtime: dc.channel('apm:aws:request:start:default').hasSubscribers === false while …:aws and …:sqs are true.

Suggested fix: static id = 'default' on Default (or publish unknown services on :aws), plus a test that a service outside the known list yields an aws.request span.

Reproduction Code

// package.json: { "type": "module" }; deps: dd-trace, @aws-sdk/client-sqs, @aws-sdk/client-sts
// run: node --import dd-trace/initialize.mjs repro.mjs
import dc from 'node:diagnostics_channel';
import tracer from 'dd-trace';
import { SQSClient, GetQueueUrlCommand } from '@aws-sdk/client-sqs';
import { STSClient, GetCallerIdentityCommand } from '@aws-sdk/client-sts';

console.log('subscribers default/aws/sqs:',
  dc.channel('apm:aws:request:start:default').hasSubscribers,
  dc.channel('apm:aws:request:start:aws').hasSubscribers,
  dc.channel('apm:aws:request:start:sqs').hasSubscribers);

// Names of the spans created while fn runs (in-process; no Agent needed).
const spans = async (fn) => {
  let names = [];
  await tracer.trace('p', async (s) => {
    const t = s.context()._trace, before = t.started.length;
    try { await fn(); } catch {}
    names = t.started.slice(before).map((x) => x.context()._name);
  });
  return names;
};

const dead = 'http://127.0.0.1:9';
const credentials = { accessKeyId: 'x', secretAccessKey: 'y' };
console.log('SQS:', await spans(() => new SQSClient({ region: 'us-east-1', endpoint: dead, credentials, maxAttempts: 1 })
  .send(new GetQueueUrlCommand({ QueueName: 'q' }))));
console.log('STS:', await spans(() => new STSClient({ region: 'us-east-1', endpoint: dead, credentials, maxAttempts: 1 })
  .send(new GetCallerIdentityCommand({}))));
setTimeout(() => process.exit(0), 100);

Output on 6.16.0 (identical on 5.109.0):

subscribers default/aws/sqs: false true true
SQS: [ 'aws.request', 'http.request', 'tcp.connect' ]
STS: [ 'http.request', 'tcp.connect' ]

Error Logs

No response

Tracer Config

DD_TRACE_ENABLED=true DD_TRACE_AGENT_URL=http://127.0.0.1:9 — no Agent is needed to reproduce; spans are observed in-process.

Operating System

macOS (Darwin 27); not platform-specific.

Bundling

No bundling