[DSM] Fix an issue where RabbitMQ producers when producing a message to the default exchange were setting checkpoints that didn't work in DSM (#5150)

Author: ericfirth

packages/datadog-plugin-amqplib/src/producer.js

@@ -36,9 +36,17 @@ class AmqplibProducerPlugin extends ProducerPlugin {
     if (this.config.dsmEnabled) {
       const hasRoutingKey = fields.routingKey != null
       const payloadSize = getAmqpMessageSize({ content: message, headers: fields.headers })
+
+      // there are two ways to send messages in RabbitMQ:
+      // 1. using an exchange and a routing key in which DSM connects via the exchange
+      // 2. using an unnamed exchange and a routing key in which DSM connects via the topic
+      const exchangeOrTopicTag = hasRoutingKey && !fields.exchange
+        ? `topic:${fields.routingKey}`
+        : `exchange:${fields.exchange}`
+
       const dataStreamsContext = this.tracer
         .setCheckpoint(
-          ['direction:out', `exchange:${fields.exchange}`, `has_routing_key:${hasRoutingKey}`, 'type:rabbitmq']
+          ['direction:out', exchangeOrTopicTag, `has_routing_key:${hasRoutingKey}`, 'type:rabbitmq']
           , span, payloadSize)
       DsmPathwayCodec.encode(dataStreamsContext, fields.headers)
     }

packages/datadog-plugin-amqplib/test/index.spec.js

@@ -306,8 +306,10 @@ describe('Plugin', () => {
         describe('when data streams monitoring is enabled', function () {
           this.timeout(10000)
 
-          const expectedProducerHash = '17191234428405871432'
-          const expectedConsumerHash = '18277095184718602853'
+          const expectedProducerHashWithTopic = '16804605750389532869'
+          const expectedProducerHashWithExchange = '2722596631431228032'
+
+          const expectedConsumerHash = '17529824252700998941'
 
           before(() => {
             tracer = require('../../dd-trace')
@@ -322,7 +324,7 @@ describe('Plugin', () => {
             return agent.close({ ritmReset: false })
           })
 
-          it('Should emit DSM stats to the agent when sending a message', done => {
+          it('Should emit DSM stats to the agent when sending a message on an unnamed exchange', done => {
             agent.expectPipelineStats(dsmStats => {
               let statsPointsReceived = []
               // we should have 1 dsm stats points
@@ -336,11 +338,11 @@ describe('Plugin', () => {
               expect(statsPointsReceived.length).to.be.at.least(1)
               expect(statsPointsReceived[0].EdgeTags).to.deep.equal([
                 'direction:out',
-                'exchange:',
                 'has_routing_key:true',
+                'topic:testDSM',
                 'type:rabbitmq'
               ])
-              expect(agent.dsmStatsExist(agent, expectedProducerHash)).to.equal(true)
+              expect(agent.dsmStatsExist(agent, expectedProducerHashWithTopic)).to.equal(true)
             }, { timeoutMs: 10000 }).then(done, done)
 
             channel.assertQueue('testDSM', {}, (err, ok) => {
@@ -350,6 +352,34 @@ describe('Plugin', () => {
             })
           })
 
+          it('Should emit DSM stats to the agent when sending a message on an named exchange', done => {
+            agent.expectPipelineStats(dsmStats => {
+              let statsPointsReceived = []
+              // we should have 1 dsm stats points
+              dsmStats.forEach((timeStatsBucket) => {
+                if (timeStatsBucket && timeStatsBucket.Stats) {
+                  timeStatsBucket.Stats.forEach((statsBuckets) => {
+                    statsPointsReceived = statsPointsReceived.concat(statsBuckets.Stats)
+                  })
+                }
+              })
+              expect(statsPointsReceived.length).to.be.at.least(1)
+              expect(statsPointsReceived[0].EdgeTags).to.deep.equal([
+                'direction:out',
+                'exchange:namedExchange',
+                'has_routing_key:true',
+                'type:rabbitmq'
+              ])
+              expect(agent.dsmStatsExist(agent, expectedProducerHashWithExchange)).to.equal(true)
+            }, { timeoutMs: 10000 }).then(done, done)
+
+            channel.assertExchange('namedExchange', 'direct', {}, (err, ok) => {
+              if (err) return done(err)
+
+              channel.publish('namedExchange', 'anyOldRoutingKey', Buffer.from('DSM pathway test'))
+            })
+          })
+
           it('Should emit DSM stats to the agent when receiving a message', done => {
             agent.expectPipelineStats(dsmStats => {
               let statsPointsReceived = []
@@ -390,11 +420,11 @@ describe('Plugin', () => {
               expect(statsPointsReceived.length).to.be.at.least(1)
               expect(statsPointsReceived[0].EdgeTags).to.deep.equal([
                 'direction:out',
-                'exchange:',
                 'has_routing_key:true',
+                'topic:testDSM',
                 'type:rabbitmq'
               ])
-              expect(agent.dsmStatsExist(agent, expectedProducerHash)).to.equal(true)
+              expect(agent.dsmStatsExist(agent, expectedProducerHashWithTopic)).to.equal(true)
             }, { timeoutMs: 10000 }).then(done, done)
 
             channel.assertQueue('testDSM', {}, (err, ok) => {
@@ -445,7 +475,7 @@ describe('Plugin', () => {
                 }
 
                 expect(produceSpanMeta).to.include({
-                  'pathway.hash': expectedProducerHash
+                  'pathway.hash': expectedProducerHashWithTopic
                 })
               }, { timeoutMs: 10000 }).then(done, done)
             })