net.server_select: Better detection of errors for outgoing connections
On connection failure, a socket is marked readable and writable. So
to detect initial connection failures (connection refused, etc.) we
now watch for sockets becoming readable during initial connection,
and also read from readable sockets before writing to writable
sockets.
This should fix 'onconnect' being called for outgoing connections
that actually failed.
local socket = require "socket";
local time = require "util.time".now
local function new(config)
if not config or not config.statsd_server then
return nil, "No statsd server specified in the config, please see https://prosody.im/doc/statistics";
end
local sock = socket.udp();
sock:setpeername(config.statsd_server, config.statsd_port or 8125);
local prefix = (config.prefix or "prosody")..".";
local function send_metric(s)
return sock:send(prefix..s);
end
local function send_gauge(name, amount, relative)
local s_amount = tostring(amount);
if relative and amount > 0 then
s_amount = "+"..s_amount;
end
return send_metric(name..":"..s_amount.."|g");
end
local function send_counter(name, amount)
return send_metric(name..":"..tostring(amount).."|c");
end
local function send_duration(name, duration)
return send_metric(name..":"..tostring(duration).."|ms");
end
local function send_histogram_sample(name, sample)
return send_metric(name..":"..tostring(sample).."|h");
end
local methods;
methods = {
amount = function (name, initial)
if initial then
send_gauge(name, initial);
end
return function (new_v) send_gauge(name, new_v); end
end;
counter = function (name, initial) --luacheck: ignore 212/initial
return function (delta)
send_gauge(name, delta, true);
end;
end;
rate = function (name)
return function ()
send_counter(name, 1);
end;
end;
distribution = function (name, unit, type) --luacheck: ignore 212/unit 212/type
return function (value)
send_histogram_sample(name, value);
end;
end;
sizes = function (name)
name = name.."_size";
return function (value)
send_histogram_sample(name, value);
end;
end;
times = function (name)
return function ()
local start_time = time();
return function ()
local end_time = time();
local duration = end_time - start_time;
send_duration(name, duration*1000);
end
end;
end;
};
return methods;
end
return {
new = new;
}