docs(daemon): evaluate epoll/kqueue connection multiplexing#3437
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Documentation-only audit of the daemon's accept-loop and per-connection threading model. Compares three paths (raw mio event loop, full tokio async accept, status quo thread-per-connection) against upstream rsync 3.4.1's select+fork model and against the existing async_session scaffold. Recommends extending the in-tree async path behind the existing async Cargo feature rather than introducing a new mio variant alongside the synchronous loop.
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…3437) Documentation-only audit of the daemon's accept-loop and per-connection threading model. Compares three paths (raw mio event loop, full tokio async accept, status quo thread-per-connection) against upstream rsync 3.4.1's select+fork model and against the existing async_session scaffold. Recommends extending the in-tree async path behind the existing async Cargo feature rather than introducing a new mio variant alongside the synchronous loop.
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…3437) Documentation-only audit of the daemon's accept-loop and per-connection threading model. Compares three paths (raw mio event loop, full tokio async accept, status quo thread-per-connection) against upstream rsync 3.4.1's select+fork model and against the existing async_session scaffold. Recommends extending the in-tree async path behind the existing async Cargo feature rather than introducing a new mio variant alongside the synchronous loop.
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Summary
Documentation-only audit (
docs/audits/daemon-event-loop-multiplexing.md)addressing task #1675: should the oc-rsync daemon adopt epoll/kqueue
event-loop multiplexing in place of the current thread-per-connection
model?
The audit:
crates/daemon/src/daemon/sections/server_runtime/{accept_loop,connection,listener,workers}.rsand the existing tokio scaffold in
crates/daemon/src/daemon/async_session/.socket.c:533start_accept_loop,which uses
select(2)over listening fds +fork(2)per connection -no per-connection multiplexing).
mio1.x event loop, (b) fulltokioaccept with
spawn_blockingworkers, (c) status quo.Recommendation: pursue option (b) - promote the existing
async_session/listener to the production accept loop behind theexisting
asyncCargo feature - but defer until a deployment withthousands of concurrent idle connections actually needs it. Reject
option (a) (would create a third accept-loop variant alongside the
sync and async paths). 8 follow-up tasks filed (#1676-#1683).
Test plan
git diffreview confirms the change is documentation-only.