File

core/s2smanager.lua @ 11523:5f15ab7c6ae5

Statistics: Rewrite statistics backends to use OpenMetrics The metric subsystem of Prosody has had some shortcomings from the perspective of the current state-of-the-art in metric observability. The OpenMetrics standard [0] is a formalization of the data model (and serialization format) of the well-known and widely-used Prometheus [1] software stack. The previous stats subsystem of Prosody did not map well to that format (see e.g. [2] and [3]); the key reason is that it was trying to do too much math on its own ([2]) while lacking first-class support for "families" of metrics ([3]) and structured metric metadata (despite the `extra` argument to metrics, there was no standard way of representing common things like "tags" or "labels"). Even though OpenMetrics has grown from the Prometheus world of monitoring, it maps well to other popular monitoring stacks such as: - InfluxDB (labels can be mapped to tags and fields as necessary) - Carbon/Graphite (labels can be attached to the metric name with dot-separation) - StatsD (see graphite when assuming that graphite is used as backend, which is the default) The util.statsd module has been ported to use the OpenMetrics model as a proof of concept. An implementation which exposes the util.statistics backend data as Prometheus metrics is ready for publishing in prosody-modules (most likely as mod_openmetrics_prometheus to avoid breaking existing 0.11 deployments). At the same time, the previous measure()-based API had one major advantage: It is really simple and easy to use without requiring lots of knowledge about OpenMetrics or similar concepts. For that reason as well as compatibility with existing code, it is preserved and may even be extended in the future. However, code relying on the `stats-updated` event as well as `get_stats` from `statsmanager` will break because the data model has changed completely; in case of `stats-updated`, the code will simply not run (as the event was renamed in order to avoid conflicts); the `get_stats` function has been removed completely (so it will cause a traceback when it is attempted to be used). Note that the measure_*_event methods have been removed from the module API. I was unable to find any uses or documentation and thus deemed they should not be ported. Re-implementation is possible when necessary. [0]: https://openmetrics.io/ [1]: https://prometheus.io/ [2]: #959 [3]: #960
author Jonas Schäfer <jonas@wielicki.name>
date Sun, 18 Apr 2021 11:47:41 +0200
parent 11418:f4b76e500768
child 11900:60676b607b6d
line wrap: on
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--



local hosts = prosody.hosts;
local pairs, setmetatable = pairs, setmetatable;

local logger_init = require "util.logger".init;
local sessionlib = require "util.session";

local log = logger_init("s2smanager");

local prosody = _G.prosody;
local incoming_s2s = {};
_G.incoming_s2s = incoming_s2s;
prosody.incoming_s2s = incoming_s2s;
local fire_event = prosody.events.fire_event;

local _ENV = nil;
-- luacheck: std none

local function new_incoming(conn)
	local host_session = sessionlib.new("s2sin");
	sessionlib.set_id(host_session);
	sessionlib.set_logger(host_session);
	sessionlib.set_conn(host_session, conn);
	host_session.direction = "incoming";
	host_session.incoming = true;
	host_session.hosts = {};
	incoming_s2s[host_session] = true;
	return host_session;
end

local function new_outgoing(from_host, to_host)
	local host_session = sessionlib.new("s2sout");
	sessionlib.set_id(host_session);
	sessionlib.set_logger(host_session);
	host_session.to_host = to_host;
	host_session.from_host = from_host;
	host_session.host = from_host;
	host_session.notopen = true;
	host_session.direction = "outgoing";
	host_session.outgoing = true;
	host_session.hosts = {};
	hosts[from_host].s2sout[to_host] = host_session;
	return host_session;
end

local resting_session = { -- Resting, not dead
		destroyed = true;
		type = "s2s_destroyed";
		direction = "destroyed";
		open_stream = function (session)
			session.log("debug", "Attempt to open stream on resting session");
		end;
		close = function (session)
			session.log("debug", "Attempt to close already-closed session");
		end;
		reset_stream = function (session)
			session.log("debug", "Attempt to reset stream of already-closed session");
		end;
		filter = function (type, data) return data; end; --luacheck: ignore 212/type
	}; resting_session.__index = resting_session;

local function retire_session(session, reason)
	local log = session.log or log; --luacheck: ignore 431/log
	for k in pairs(session) do
		if k ~= "log" and k ~= "id" and k ~= "conn" then
			session[k] = nil;
		end
	end

	session.destruction_reason = reason;

	function session.send(data) log("debug", "Discarding data sent to resting session: %s", data); end
	function session.data(data) log("debug", "Discarding data received from resting session: %s", data); end
	session.thread = { run = function (_, data) return session.data(data) end };
	session.sends2s = session.send;
	return setmetatable(session, resting_session);
end

local function destroy_session(session, reason, bounce_reason)
	if session.destroyed then return; end
	local log = session.log or log;
	log("debug", "Destroying %s session %s->%s%s%s", session.direction, session.from_host, session.to_host, reason and ": " or "", reason or "");

	if session.direction == "outgoing" then
		hosts[session.from_host].s2sout[session.to_host] = nil;
		session:bounce_sendq(bounce_reason or reason);
	elseif session.direction == "incoming" then
		if session.outgoing then
			hosts[session.to_host].s2sout[session.from_host] = nil;
		end
		incoming_s2s[session] = nil;
	end

	local event_data = { session = session, reason = reason };
	if session.type == "s2sout" then
		fire_event("s2sout-destroyed", event_data);
		if hosts[session.from_host] then
			hosts[session.from_host].events.fire_event("s2sout-destroyed", event_data);
		end
	elseif session.type == "s2sin" then
		fire_event("s2sin-destroyed", event_data);
		if hosts[session.to_host] then
			hosts[session.to_host].events.fire_event("s2sin-destroyed", event_data);
		end
	end

	retire_session(session, reason); -- Clean session until it is GC'd
	return true;
end

return {
	incoming_s2s = incoming_s2s;
	new_incoming = new_incoming;
	new_outgoing = new_outgoing;
	retire_session = retire_session;
	destroy_session = destroy_session;
};