Ability to set LINGER when creating RPC connections

[achimnol]

Setting the transport's zmq.LINGER option only applies to newly created sockets, which is not the case for RPC connections where socket creation is done inside create_zmq_connection() called by serve_rpc() or connect_rpc().

It works as expected if I change to serve_rpc() and connect_rpc() to use pre-existing zmq sockets like this, but there seems no way to set it without modifying aiozmq:

@asyncio.coroutine
def serve_rpc(handler, *, connect=None, bind=None, loop=None,
              translation_table=None, log_exceptions=False,
              exclude_log_exceptions=(), timeout=None):
    ...
    ctx = zmq.Context.instance()
    sock = ctx.socket(zmq.ROUTER)    # duplicate with below call
    sock.setsockopt(zmq.LINGER, 50)  # need some way to generalize this part
    transp, proto = yield from create_zmq_connection(
        lambda: _ServerProtocol(loop, handler,
                                translation_table=translation_table,
                                log_exceptions=log_exceptions,
                                exclude_log_exceptions=exclude_log_exceptions,
                                timeout=timeout),
        zmq.ROUTER, connect=connect, bind=bind, zmq_sock=sock, loop=loop)
    return Service(loop, proto)

We just could add yet-another keyword argument such as linger to servce_rpc() and connect_rpc(), but it seems not very clean. If we add zmq_sock argument like in create_zmq_connection(), then there will be duplicates of settings socket types inside/outside aiozmq. Maybe, we could add a global default socket option table in the aiozmq.rpc module level that can be set in prior to calling serve_rpc() or connect_rpc().

What are your thoughts on setting socket options for aiozmq.rpc?

[achimnol]

Ooops, I found that I was confused with my prior experiences...
Settings transport's linger option works after serve_rpc() or connect_rpc() actually!
Sorry for bothering you.