[q3k]

You don’t :).

To do it properly you want a maglev-style layer that allows for withdrawals/drains of application servers with minimal disruption thanks to a minimum disruption maglev-style hash and draining support. This will allow you to first drain the given application server (continue maintaining existing connections, but send new ones to a secondaries for that part shard) before fully taking down the instance.

[rhizome]

Sounds like Apache's graceful-restart.

[transitorykris]

Sort of. Processes on the same node (graceful restart) vs processes on different nodes (maglev).

[rhizome]

Eh, a signal is a signal even if it's an RPC, but my point was to focus on the "waiting for something to end or empty before restarting" part.