Sharding recovery

In this section, we will explore different failure types and how we can recover in a sharded environment. Failure in a distributed system can take multiple forms and shapes. In this section we will cover all the possible cases, from the simplest case of a stateless component like mongos failing to an entire shard going down.

mongos

The mongos process is a relatively lightweight process that holds no state. In the case that the process fails, we can just restart it or spin up a new process in a different server. It's recommended that mongos processes are located in the same server as our application, and so it makes sense to connect from our application using the set of mongos servers that we have colocated...