Postgres instrumentation creates a new span every time even when part of a request

[iAmMrinal0]

I am using the zipkin express middleware with zipkin postgres and when I look in the zipkin dashboard, the middleware service shows up as a separate span and postgres as a separate span even though they are part of the same request. And this breaks any further traces for other services I have, like redis, axios. As seen in the image, all spans above express_middleware should have been a part of it and not separate on their own. If you could guide me as to what to change in the postgres instrumentation, that would be helpful too.

How it shows up:

How I am expecting it(this is for a different request which doesn't hit postgres):

Edit: Adding a few changes I have made to postgres instrumentation as I use an older version of pg

Changed the following few lines:

zipkin-js/packages/zipkin-instrumentation-postgres/src/zipkinClient.js

Line 73 in 00a288c

return promise.then(() => {

to:

promise.on('end', function () {
  annotateSuccess(id);
});
promise.on('error', function (error) {
  annotateError(id, error);
});
return promise;

[jcchavezs]

Do you use CLS to keep the trace across spans into the same request?

[iAmMrinal0]

Yes, I do use CLS in all the instrumentations.

[iAmMrinal0]

I missed mentioning an important part of the setup, which is sequelize. I had to add CLS to sequelize and I checked zipkin-context-cls which was getting or creating the zipkin namespace for the CLS. That solved the issue.

[jcchavezs]

Thanks for inform this. Would you change something in the documentation to avoid future confusions?

[saasen]

@iAmMrinal0: Are you only using useCLS on sequlize, or do you manually trace stuff yourself? Does simply adding useCLS('zipkin') give you tracing against Postgres? Nothing of this works for me.

[iAmMrinal0]

I had to manually trace each component I wanted. useCls('zipkin') only makes sure the context is passed further down the line to your other tracing components. So I had to modify the postgres related connection code in sequelize at that time.
Please note that, my knowledge is based on when I worked on it, which was around the time I created the issue. It could be possible that things have changed in sequelize/zipkin-js side to allow for easier tracing support. I hope I was helpful and answered what you were looking for.