From Rack to 502, com Felipe Roveran Ribeiro

HTTP error 502 is very frequent and sometimes really annoying, as its causes can be very hidden and difficult to investigate. In this talk we will see an overview of what happens since we send a request to the server until it is processed by Rails. During this process, we will walk through web-servers and application-servers, comparing and understand their purpose and how to configure them. With this, we will be able to identify the exact point where HTTP 502 comes to place and then detect its causes. We will explore different ways to identify the root cause and, to do so, building a rack middleware capable of tracking time-consuming requests and logging relevant info. At the end, we will see a few root-causes and even more advanced Postgres’ tools like vacuum and query-planner.

Felipe Roveran Ribeiro: Hardware lover and, travelling through the mysteries of microprocessors and microcontrollers, now enjoying the backstage of the www world