We’ve recently migrated to the new HTTP/2 API to send out push notifications to iOS devices, for greater throughput and reliability (as compared to the binary protocol).
As such, to stress test our system, we needed a mock HTTP/2 APNS server. Instinctively, we explored various ways to build one in Java, which is what most of our core system is written in. However, at this time, HTTP/2 support in Java seems to be very weak, with just a client available from the Jetty project.
Next up was Python, using the Hyper library. We wrote one inspired from the asyncio library example found here. For some reason, Jetty’s HTTP/2 transport library couldn’t play nicely with the Python server, however, the Chrome browser could. We didn’t have the time to investigate what was going on, and then we moved to Go.