Are Traces always pushed to a collector or can traces from an application be also pulled (scraped) like Prometheus Metrics?

[shantanoo-desai]

As the question is posed, does OTLP exporter always implemented to push traces from an application to a collector or is there also an option that a collector can scrape OTLP traces from an endpoint exposed from the app (/traces) similar to Prometheus metrics (/metrics)?

[JayeshHire]

I don't think for traces we have pulling mechanism. For metrics they have implemented this because metric backends like Prometheus primarily support the pull based mechanism.
This decision is also dependant on the nature of traces and metrics and how they behave while collecting data about the application. Traces are used to know the path of a request in an application. While, metrics are used for getting the measurements of a system at a given point in time. So, ideally we just collect metrics for a certain timeframe and traces are generated when user makes a request. Hence, technically we know that metrics should be collected after a fixed time interval. But we don't know the exact moment when the traces should be collected as they are generated continuously based on the user behaviour.
I think though we could implement pull based approach for traces also with some engineering. But I don't think it is ideal.

I hope your doubt gets cleared with my comment.
These are just my opinions I have not read it anywhere so there might be some caveats to it.