Creating Linked Traces between SQS Producer and Consumer on Non Serverless Compute

[briananstett]

I've been trying to get something similar to what is discussed in this Tracing event-driven application documentation where the traces created upstream from the producer are able to be linked to traces from downstream consumers.

The documentation highlight the capability for Lambda and SQS but I was wondering if the same thing can be achieved outside of Lambda (EC2, containers, etc).

From my testing and following what thought to be related GitHub Issues (#208, #419) I feel like I'm close, but I'm not seeing the same "linking" behavior or the This trace is poart of a linked set of traces messages on the traces as shown in the documentation.

I have a simple ExpressJS web app that is creating the SQS messages with XRay Tracing header as an attribute.

const AWSXRay = require("aws-xray-sdk");
const XRayExpress = AWSXRay.express;
const express = require("express");
const { SQSClient, SendMessageCommand } = require("@aws-sdk/client-sqs");

const app = express();
const port = 3000;

app.use(XRayExpress.openSegment("simple-api"));

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).send("Something broke!");
});

app.get("/sqs", async (req, res) => {
  const sqs = AWSXRay.captureAWSv3Client(
    new SQSClient({ region: "us-east-1" })
  );
  const params = {
    QueueUrl: "<queue url here>",
    MessageBody: JSON.stringify({ message: "body here" }),
  };
  await sqs.send(new SendMessageCommand(params));
  res.send("ok");
});

app.use(XRayExpress.closeSegment());

app.listen(port, () => console.log(`Example app listening on port ${port}!`));

And a simple consumer that is pulling the messages, creating a new segment from the values in XRayTracing header, creating an example subsegment to simulate processing logic, then closing the segment.

const AWSXRay = require("aws-xray-sdk-core");
const {
  SQSClient,
  ReceiveMessageCommand,
  DeleteMessageCommand,
} = require("@aws-sdk/client-sqs");

// Initialize SQS client
const sqsClient = new SQSClient({ region: "us-east-1" });

async function processMessages(queueUrl) {
  const receiveParams = {
    QueueUrl: queueUrl,
    AttributeNames: ["All"],
    WaitTimeSeconds: 20, // Enable long polling
  };

  while (true) {
    const received = await sqsClient.send(
      new ReceiveMessageCommand(receiveParams)
    );

    if (received.Messages) {
      for (const message of received.Messages) {
        const traceHeaderStr = message.Attributes.AWSTraceHeader;

        // Check if the traceHeaderStr is available and valid
        if (traceHeaderStr) {
          const traceData = AWSXRay.utils.processTraceData(traceHeaderStr);

          // Inside this context, we can now work with X-Ray segments
          const segment = new AWSXRay.Segment(
            "SQSMessageProcessing",
            traceData.root, // Root ID from the trace header
            traceData.parent // Parent ID from the trace header
          );

          try {
            const subsegment = segment.addNewSubsegment("processingFunction");
            setTimeout(() => {
              subsegment.close();
            }, 500);
            const deleteParams = {
              QueueUrl: queueUrl,
              ReceiptHandle: message.ReceiptHandle,
            };
            await sqsClient.send(new DeleteMessageCommand(deleteParams));
          } catch (error) {
            console.error("Error processing message:", error);
            segment.addError(error); // Add error to segment
          } finally {
            // Close the segment after processing
            segment.close();
          }
        }
      }
    }
  }
}

// Replace 'YOUR_SQS_QUEUE_URL' with your actual SQS queue URL
processMessages(
  "<queue url here>"
).catch(console.error);

From the screenshots below, you'll see that a single trace is created containing sub/segments create by my "API" and the sub/segments create by my "consumer". I was expecting to seeing something like what is highlighted in the Tracing event-driven application documentation where multiple traces are created and then "linked" together.

Another issue I'm having with this implementation is that XRay capture functions can't seem to find the current context.

If I add a little bit more logic to my consumer code to try and simulate capturing outgoing HTTPS calls from the consumer

const AWSXRay = require("aws-xray-sdk-core");
const {
  SQSClient,
  ReceiveMessageCommand,
  DeleteMessageCommand,
} = require("@aws-sdk/client-sqs");
const https = require("https");

// Initialize SQS client
const sqsClient = new SQSClient({ region: "us-east-1" });

async function processMessages(queueUrl) {
  const receiveParams = {
    QueueUrl: queueUrl,
    AttributeNames: ["All"],
    WaitTimeSeconds: 20, // Enable long polling
  };

  while (true) {
    const received = await sqsClient.send(
      new ReceiveMessageCommand(receiveParams)
    );

    if (received.Messages) {
      console.log("Received messages:", received.Messages);
      for (const message of received.Messages) {
        const traceHeaderStr = message.Attributes.AWSTraceHeader;

        // Check if the traceHeaderStr is available and valid
        if (traceHeaderStr) {
          const traceData = AWSXRay.utils.processTraceData(traceHeaderStr);

          // Inside this context, we can now work with X-Ray segments
          const segment = new AWSXRay.Segment(
            "SQSMessageProcessing",
            traceData.root, // Root ID from the trace header
            traceData.parent // Parent ID from the trace header
          );

          AWSXRay.captureHTTPsGlobal(https);

          try {
            const subsegment = segment.addNewSubsegment("processingFunction");
            setTimeout(() => {
              https.get("https://amazon.com/", (response) => {
                response.on("data", () => {});

                response.on("error", (err) => {
                  console.error(err);
                  subsegment.close();
                });

                response.on("end", () => {
                  subsegment.close();
                });
              });
            }, 500);
            const deleteParams = {
              QueueUrl: queueUrl,
              ReceiptHandle: message.ReceiptHandle,
            };
            await sqsClient.send(new DeleteMessageCommand(deleteParams));
          } catch (error) {
            console.error("Error processing message:", error);
            segment.addError(error); // Add error to segment
          } finally {
            // Close the segment after processing
            segment.close();
          }
        }
      }
    }
  }
}

// Replace 'YOUR_SQS_QUEUE_URL' with your actual SQS queue URL
processMessages(
  "https://sqs.us-east-1.amazonaws.com/785630775706/xray-test"
).catch(console.error);

I get the classic [ERROR] Error: Failed to get the current sub/segment from the context. error.

Thank you for any support and if there is better documentation somewhere on how to implement thorough tracing for applications that use SQS on "non-serverless" compute (containers, EC2, etc), please let me know.

[wangzlei]

The documentation highlight the capability for Lambda and SQS but I was wondering if the same thing can be achieved outside of Lambda (EC2, containers, etc).

Unfortunately, xray service supports links for SQS -> Lambda case only, user cannot manage segment links by API.

[briananstett]

Thank you @wangzlei for your response. With Xray only supporting links for SQS and Lambda, do you have an suggestions on how I could trace applciations that use SQS but aren't using lambda? Should I continue to create a new segment from the trace header values in the SQS message?

My only problem with that was, when I create a segment in the SQS consumer from the trace header values,

const traceData = AWSXRay.utils.processTraceData(traceHeaderStr);

  // Inside this context, we can now work with X-Ray segments
 const segment = new AWSXRay.Segment(
  "SQSMessageProcessing",
  traceData.root, // Root ID from the trace header
  traceData.parent // Parent ID from the trace header
);

I can't seem to get other capture functions that use Auto Mode to detect the current context/segment.

AWSXRay.captureHTTPsGlobal(https);

I get the [ERROR] Error: Failed to get the current sub/segment from the context. error. Do you know how I could set the current context manually after I create the new segment from trace header values in the SQS message?