AWSXRay.captureAsyncFunc() from Lambda - am I missing something?

Question

I'm trying to get a custom X-Ray segment reporting, but I'm not seeing anything in the trace. My code looks something like this:

var AWSXRay = require('aws-xray-sdk-core');

AWSXRay.captureAsyncFunc('callSoapService', subsegment => {
  doSomethingAsync(params, err => {
    if (err) {
      subsegment.close(err);
    } else {
      doSomethingElse().then(result => {
        console.info('all done, now close the segment');
        subsegment.close();
      }, subsegment.close);
    }
  });
});

Do I need to add it to the parent segment or something?

score 1 · Answer 1 · answered Oct 18 '17 at 05:13

1

ugh. there seems to be a bug with AWSXRay.captureHTTPs() - if I remove that call captureAsyncFunc() starts working

answered Oct 18 '17 at 05:13

Nicholas Albion

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AWSSandra · Answer 2 · 2017-10-19T19:23:24.957

1

For the AWS X-Ray Node SDK, automatic mode is build on the continuation-local-storage (cls) package which has known compatibility issues with promise libraries. This is why your 'then' seems to be losing context. However, most of these libraries have various CLS shims available to provide the compatibility necessary to work.

Which promise library are you using? For bluebird, there's 'cls-bluebird' or for Q there's 'cls-q' that's available that will get it working.

They usually ask to pass in the CLS namespace, which is available from xray.getNamespace().

Hope this helps.

edited Oct 19 '17 at 19:23

answered Oct 19 '17 at 19:18

AWSSandra

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I'm using native Node Promises – Nicholas Albion Oct 19 '17 at 22:59
Is CLS safe to use in the back-end where multiple requests may be served concurrently? – Nicholas Albion Oct 19 '17 at 23:03
CLS stores variables scoped to function call chains, akin to thread-local storage. It needs shims for 3rd party library promise support. You can read more about it here: https://github.com/othiym23/node-continuation-local-storage – AWSSandra Oct 26 '17 at 18:55

AWSXRay.captureAsyncFunc() from Lambda - am I missing something?

2 Answers2