You can do this with TCP keepalives [0]. Under Linux, a process can enable the SO_KEEPALIVE option on sockets to request that the Linux kernel send TCP keepali

You can do this with TCP keepalives [0]. Under Linux, a process can enable the SO_KEEPALIVE option on sockets to request that the Linux kernel send TCP keepalives periodically. A kernel option determines how frequently the kernel sends TCP keepalive packets. It is a single option that applies to all sockets of all processes. One can also configure the OS to enable SO_KEEPALIVE by default on all sockets of all processes. Golang's GRPC library implements keepalives at the GRPC protocol level [1]. It provides a `Context` value [2] that code can use to detect peer disconnect and cancel expensive operations. Golang's HTTP server API does not provide any way to detect peer disconnect before sending the final response [3]. Rust cannot set SO_KEEPALIVE [4]. One could possibly implement keepalives by writing zero-length chunks to the socket. Java's Netty server library can set SO_KEEPALIVE [5]. One can then code a request handler that periodically checks if the socket is connected [6] and cancels expensive operations. Unfortunately, there is standard tooling to do this. EDIT: You did mention TCP keepalives. I was not aware that some routers drop them. Can you link to any data on the prevalence of tcp-keepalive dropping for various kinds of client connections: home router, corporate wifi, mobile carrier-grade-NAT? [0] https://tldp.org/HOWTO/TCP-Keepalive-HOWTO/overview.html https://tldp.org/HOWTO/TCP-Keepalive-HOWTO/overview.html [1] https://pkg.go.dev/google.golang.org/grpc/keepalive https://pkg.go.dev/google.golang.org/grpc/keepalive [2] https://pkg.go.dev/google.golang.org/grpc#ServerStream https://pkg.go.dev/google.golang.org/grpc#ServerStream [3] https://pkg.go.dev/net/http#HandlerFunc https://pkg.go.dev/net/http#HandlerFunc [4] https://github.com/rust-lang/rust/issues/69774 https://github.com/rust-lang/rust/issues/69774 [5] https://netty.io/4.1/api/io/netty/channel/ChannelOption.html#SO_KEEPALIVE https://netty.io/4.1/api/io/netty/channel/ChannelOption.html... [6] https://netty.io/4.1/api/io/netty/channel/Channel.html#isOpen-- https://netty.io/4.1/api/io/netty/channel/Channel.html#isOpe...