R' Reject matching queries. L' Check request line for matching strings. Exit requests Process can close its pipes or sockets and exit at any time, although that causes requests that are sent to it to be dropped. Since pipes and sockets do asynchronous data transfer, it's possible to drop the request while it's being sent from the server, so while it's acceptable for emergency exit, clean exit procedure should guarantee that no requests that are already sent to processes, are dropped. Server continues sending and receiving messages for requests that are in progress, although does not send new requests to the instance that requested exit.
Process can exit.
That will cause HTTP server to continue sending requests to the process.