Introduction

This repository contains a simple ASP.Net service that reproduces a memory leak in the Sentry integration with OpenTelemetry when using a request filter with the OpenTelemetry HTTP client instrumentation.

Running the service

Before running the service you must replace the dummy DSN http://your.dsn.here with a valid DSN

Once the DSN is configured simply start the service and using a memory profiler, note that TransactionTracer instances start accumulating inside SentrySpanProcessor._map which are never removed. These correlate to the number of filtered requests.

Code Notes

The hosted service OutgoingRequestsHostedService sends requests to itself to trigger the behaviour.

The static class HttpRequestFiltering contains a simple method to decide whether to sample an HttpRequestMessage based on a random number. It also counts the number of collected vs filtered requests - note that the number of leaked instances correlates with the number of filtered requests, as reported to the console. Changing shouldCollect to always be true resolves the leak, demonstrating that the act of filtering a HttpRequestMessage appears to cause the leak.