dd-trace/packages/datadog-plugin-bullmq/src/consumer.js

Datadog APM tracing client for JavaScript

'use strict'

const log = require('../../dd-trace/src/log')
const ConsumerPlugin = require('../../dd-trace/src/plugins/consumer')
const { getMessageSize } = require('../../dd-trace/src/datastreams')

class BullmqConsumerPlugin extends ConsumerPlugin {
  static id = 'bullmq'
  static prefix = 'tracing:orchestrion:bullmq:Worker_callProcessJob'

  asyncEnd (ctx) {
    ctx.currentStore?.span?.finish()
  }

  start (ctx) {
    if (!this.config.dsmEnabled) return
    const { span } = ctx.currentStore
    this.setConsumerCheckpoint(span, ctx)
  }

  bindStart (ctx) {
    const job = ctx.arguments?.[0]
    const queueName = job?.queueName || job?.queue?.name || 'bullmq'

    let childOf
    const ddCarrier = this._extractDatadog(job)
    if (ddCarrier) {
      ctx._ddCarrier = ddCarrier
      childOf = this.tracer.extract('text_map', ddCarrier)
    }

    this.startSpan({
      childOf,
      resource: queueName,
      meta: {
        component: 'bullmq',
        'span.kind': 'consumer',
        'messaging.system': 'bullmq',
        'messaging.destination.name': queueName,
        'messaging.operation': 'process',
      },
    }, ctx)

    return ctx.currentStore
  }

  setConsumerCheckpoint (span, ctx) {
    const job = ctx.arguments?.[0]
    if (!job) return

    const queueName = job.queueName || job.queue?.name || 'bullmq'
    const payloadSize = job.data ? getMessageSize(job.data) : 0

    const ddCarrier = ctx._ddCarrier
    if (ddCarrier) {
      this.tracer.decodeDataStreamsContext(ddCarrier)
    }

    const edgeTags = ['direction:in', `topic:${queueName}`, 'type:bullmq']
    this.tracer.setCheckpoint(edgeTags, span, payloadSize)
  }

  _extractDatadog (job) {
    const metadataStr = job?.opts?.telemetry?.metadata
    if (!metadataStr) return

    try {
      const metadata = JSON.parse(metadataStr)
      const ddCarrier = metadata._datadog
      if (!ddCarrier) return

      // Avoid `delete`'s hidden-class transition; JSON.stringify also omits undefined values.
      metadata._datadog = undefined
      job.opts.telemetry.metadata = JSON.stringify(metadata)

      return ddCarrier
    } catch (error) {
      log.warn('bullmq: skipping _datadog extract on malformed telemetry.metadata: %s', error.message)
    }
  }
}

module.exports = BullmqConsumerPlugin