Nine Nines: ranch

ranch_tcp(3)

Name

ranch_tcp - TCP transport module

Description

The ranch_tcp module implements a TCP Ranch transport.

Note that due to bugs in OTP up to at least R16B02, it is +recommended to disable async threads when using the +sendfile function of this transport, as it can make +the threads stuck indefinitely.

Types

opt()

opt() = {backlog, non_neg_integer()}
+        | {buffer, non_neg_integer()}
+        | {delay_send, boolean()}
+        | {dontroute, boolean()}
+        | {exit_on_close, boolean()}
+        | {fd, non_neg_integer()}
+        | {high_msgq_watermark, non_neg_integer()}
+        | {high_watermark, non_neg_integer()}
+        | inet
+        | inet6
+        | {ip, inet:ip_address()}
+        | {ipv6_v6only, boolean()}
+        | {keepalive, boolean()}
+        | {linger, {boolean(), non_neg_integer()}}
+        | {low_msgq_watermark, non_neg_integer()}
+        | {low_watermark, non_neg_integer()}
+        | {nodelay, boolean()}
+        | {port, inet:port_number()}
+        | {priority, integer()}
+        | {raw, non_neg_integer(), non_neg_integer(), binary()}
+        | {recbuf, non_neg_integer()}
+        | {send_timeout, timeout()}
+        | {send_timeout_close, boolean()}
+        | {sndbuf, non_neg_integer()}
+        | {tos, integer()}

Listen options.

This does not represent the entirety of the options that can +be set on the socket, but only the options that may be +set independently of protocol implementation.

opts() = [opt()]

List of listen options.

Option descriptions

None of the options are required.

Please consult the gen_tcp and inet manuals for a more +thorough description of these options. This manual only aims +to provide a short description along with what the defaults +are. Defaults may be different in Ranch compared to gen_tcp. +Defaults are given next to the option name.

+backlog (1024) +: +
+ Max length of the queue of pending connections. +
+
+buffer +: +
+ Size of the buffer used by the Erlang driver. Default is system-dependent. +
+
+delay_send (false) +: +
+ Always queue packets before sending, to send fewer, larger packets over the network. +
+
+dontroute (false) +: +
+ Don’t send via a gateway, only send to directly connected hosts. +
+
+exit_on_close (true) +: +
+ Disable to allow sending data after a close has been detected. +
+
+fd +: +
+ File descriptor of the socket, if it was opened externally. +
+
+high_msgq_watermark (8192) +: +
+ Limit in the amount of data in the socket message queue before the socket queue becomes busy. +
+
+high_watermark (8192) +: +
+ Limit in the amount of data in the ERTS socket implementation’s queue before the socket becomes busy. +
+
+inet +: +
+ Set up the socket for IPv4. +
+
+inet6 +: +
+ Set up the socket for IPv6. +
+
+ip +: +
+ Interface to listen on. Listen on all interfaces by default. +
+
+ipv6_v6only (false) +: +
+ Listen on IPv4 and IPv6 (false) or only on IPv6 (true). Use with inet6. +
+
+keepalive (false) +: +
+ Enable sending of keep-alive messages. +
+
+linger ({false, 0}) +: +
+ Whether to wait and how long to flush data sent before closing the socket. +
+
+low_msgq_watermark (4096) +: +
+ Amount of data in the socket message queue before the socket queue leaves busy state. +
+
+low_watermark (4096) +: +
+ Amount of data in the ERTS socket implementation’s queue before the socket leaves busy state. +
+
+nodelay (true) +: +
+ Whether to enable TCP_NODELAY. +
+
+port (0) +: +
+ TCP port number to listen on. 0 means a random port will be used. +
+
+priority (0) +: +
+ Priority value for all packets to be sent by this socket. +
+
+recbuf +: +
+ Minimum size of the socket’s receive buffer. Default is system-dependent. +
+
+send_timeout (30000) +: +
+ How long the send call may wait for confirmation before returning. +
+
+send_timeout_close (true) +: +
+ Whether to close the socket when the confirmation wasn’t received. +
+
+sndbuf +: +
+ Minimum size of the socket’s send buffer. Default is system-dependent. +
+
+tos +: +
+ Value for the IP_TOS IP level option. Use with caution. +
+

In addition, the raw option can be used to set system-specific +options by specifying the protocol level, the option number and +the actual option value specified as a binary. This option is not +portable. Use with caution.

Exports

None.

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