Lighttpd

gw_backend will kill a child process if it's been unused for more than idle-timeout s and is currently unused. The unused time is calculated based on last_used, however last_used is only updated when the child is spawned, when a client connects, and in gw_recv_response, which from what I understand is used when handling HTTP data. This works fine for something like mod_fastcgi were connections are brief and only handles a single request, however in mod_wstunnel you get long running connections, where the child is then considered to have been idle since the connection started, even though it was just used.

So if you reload a page using a websocket, the child is instantly killed on disconnect, and then immediately restarted when the page connects again. Instead, the child should be killed idle-timeout s after the it was actually used, maybe idle-timeout s after disconnect or idle-timeout s after data was sent on the socket.