esockd 
Erlang General Non-blocking TCP/SSL Socket Server.
Features
- General Non-blocking TCP/SSL Socket Server
- Acceptor Pool and Asynchronous TCP Accept
- UDP/DTLS Server
- Max connections management
- Allow/Deny by peer address
- Proxy Protocol V1/V2
- Keepalive Support
- Rate Limit
- IPv6 Support
Usage
A Simple TCP Echo Server:
-module(echo_server).
-export([start_link/2, init/2]).
start_link(Transport, Sock) ->
{ok, spawn_link(?MODULE, init, [Transport, Sock])}.
init(Transport, Sock) ->
case Transport:wait(Sock) of
{ok, NewSock} ->
loop(Transport, NewSock);
Error -> Error
end.
loop(Transport, Sock) ->
case Transport:recv(Sock, 0) of
{ok, Data} ->
{ok, Peername} = Transport:peername(Sock),
Transport:send(Sock, Data),
loop(Transport, Sock);
{error, Reason} ->
io:format("TCP Error: ~s~n", [Reason]),
{stop, Reason}
end.
Setup Echo Server:
%% Start esockd application
ok = esockd:start().
Options = [{acceptors, 10}, {max_connections, 1024}, {tcp_options, [binary, {reuseaddr, true}]}].
MFArgs = {echo_server, start_link, []},
esockd:open(echo, 5000, Options, MFArgs).
Examples
| Example | Description |
|---|---|
| examples/async_recv | prim_net async recv/send |
| examples/gen_server | gen_server behaviour |
| examples/simple | simple echo server |
| examples/ssl | ssl echo server |
| examples/proxy_protocol | proxy protocol v1/2 |
| examples/udp | udp echo server |
| examples/dtls | dtls echo server |
API
Open a listener
esockd:open(echo, 5000, [{tcp_options, [binary, {reuseaddr, true}]}],
{echo_server, start_link, []}).
esockd:open(echo, {"127.0.0.1", 6000}, [{tcp_options, [binary, {reuseaddr, true}]}],
{echo_server, start_link, []}).
Spec:
-spec(open(Protocol, ListenOn, Options, MFArgs) -> {ok, pid()} | {error, term()} when
Protocol :: atom(),
ListenOn :: inet:port_number() | {host(), inet:port_number()}),
Options :: [option()],
MFArgs :: esockd:mfargs()).
Option:
-type(option() :: {acceptors, pos_integer()}
| {max_connections, pos_integer()}
| {max_conn_rate, pos_integer()}
| {access_rules, [esockd_access:rule()]}
| {shutdown, brutal_kill | infinity | pos_integer()}
| tune_buffer | {tune_buffer, boolean()}
| proxy_protocol | {proxy_protocol, boolean()}
| {proxy_protocol_timeout, timeout()}
| {ssl_options, [ssl:ssl_option()]}
| {udp_options, [gen_udp:option()]}
| {dtls_options, [gen_udp:option() | ssl:ssl_option()]}).
MFArgs:
-type(mfargs() :: atom() | {atom(), atom()} | {module(), atom(), [term()]}).
Get Setting and Stats
Get stats:
esockd:get_stats({echo, 5000}).
Get acceptors:
esockd:get_acceptors({echo, {"127.0.0.1", 6000}}).
Get/Set max connections:
esockd:get_max_connections({echo, 5000}).
esockd:set_max_connections({echo, 5000}, 100000).
Allow/Deny
Same to Allow/Deny Syntax of nginx:
allow address | CIDR | all;
deny address | CIDR | all;
allow/deny by options:
esockd:open(echo, 5000, [{access, [{deny, "192.168.1.1"}, {allow, "192.168.1.0/24"}, {deny, all}]}], MFArgs).
allow/deny by API:
esockd:allow({echo, 5000}, all).
esockd:allow({echo, 5000}, "192.168.0.1/24").
esockd:deny({echo, 5000}, all).
esockd:deny({echo, 5000}, "10.10.0.0/16").
Close a listener
esockd:close(echo, 5000).
esockd:close(echo, {"127.0.0.1", 6000}).
Spec:
-spec(close(Protocol, ListenOn) -> ok when Protocol :: atom(), ListenOn :: inet:port_number() | {host(), inet:port_number()}).
SSL
Connecting to ssl_echo_server:
openssl s_client -connect 127.0.0.1:5000 -ssl3
openssl s_client -connect 127.0.0.1:5000 -tls1
Design
Supervisor Tree
esockd_sup
-> esockd_listener_sup
-> esockd_listener
-> esockd_acceptor_sup
-> esockd_acceptor
-> esockd_acceptor
-> ......
-> esockd_connection_sup
-> esockd_connection
-> esockd_connection
-> ......
Acceptor
-
Acceptor Pool
-
Suspend for one second when e{n, m}file errors happened
Connection Sup
-
Create a connection, and let it run...
-
Control maximum connections
-
Count active connections
-
Count shutdown reasons
CIDR
CIDR Wiki: https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing
Benchmark
Benchmark 2.1.0-alpha release on one 8 cores, 32G memory ubuntu/14.04 server::
250K concurrent connections, 50K messages/sec, 40Mbps In/Out consumed 5G memory, 20% CPU/core
License
Apache License Version 2.0
Author
EMQ X Team.
