Recently I had a customer reporting stalls in his Apache httpd installation. Those were happening on HTTP/2 requests. It took minutes before a response was sent to the client. What was going on? The installation used Apache as a reverse proxy for an application server, a very common setup, and the app server used Server Sent Events (SSE) with browser clients. SSE are GET request that are meant to run for a very long time (in HTTP’s definition of “long”). Whenever something happens in th...
