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net/server.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 | 10853:0107ed6744aa |
child | 11762:54530085dffe |
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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. -- if not (prosody and prosody.config_loaded) then -- This module only supports loading inside Prosody, outside Prosody -- you should directly require net.server_select or server_event, etc. error(debug.traceback("Loading outside Prosody or Prosody not yet initialized"), 0); end local log = require "util.logger".init("net.server"); local have_util_poll = pcall(require, "util.poll"); local default_backend = have_util_poll and "epoll" or "select"; local server_type = require "core.configmanager".get("*", "network_backend") or default_backend; if require "core.configmanager".get("*", "use_libevent") then server_type = "event"; end if server_type == "event" then if not pcall(require, "luaevent.core") then log("error", "libevent not found, falling back to select()"); server_type = "select" end end local server; local set_config; if server_type == "event" then server = require "net.server_event"; local defaults = {}; for k,v in pairs(server.cfg) do defaults[k] = v; end function set_config(settings) local event_settings = { ACCEPT_DELAY = settings.accept_retry_interval; ACCEPT_QUEUE = settings.tcp_backlog; CLEAR_DELAY = settings.event_clear_interval; CONNECT_TIMEOUT = settings.connect_timeout; DEBUG = settings.debug; HANDSHAKE_TIMEOUT = settings.ssl_handshake_timeout; MAX_CONNECTIONS = settings.max_connections; MAX_HANDSHAKE_ATTEMPTS = settings.max_ssl_handshake_roundtrips; MAX_READ_LENGTH = settings.max_receive_buffer_size; MAX_SEND_LENGTH = settings.max_send_buffer_size; READ_TIMEOUT = settings.read_timeout; WRITE_TIMEOUT = settings.send_timeout; }; for k,default in pairs(defaults) do server.cfg[k] = event_settings[k] or default; end end elseif server_type == "select" then server = require "net.server_select"; local defaults = {}; for k,v in pairs(server.getsettings()) do defaults[k] = v; end function set_config(settings) local select_settings = {}; for k,default in pairs(defaults) do select_settings[k] = settings[k] or default; end server.changesettings(select_settings); end else server = require("net.server_"..server_type); set_config = server.set_config; if not server.get_backend then function server.get_backend() return server_type; end end end -- If server.hook_signal exists, replace signal.signal() local has_signal, signal = pcall(require, "util.signal"); if has_signal then if server.hook_signal then function signal.signal(signal_id, handler) if type(signal_id) == "string" then signal_id = signal[signal_id:upper()]; end if type(signal_id) ~= "number" then return false, "invalid-signal"; end return server.hook_signal(signal_id, handler); end else server.hook_signal = signal.signal; end else if not server.hook_signal then server.hook_signal = function() return false, "signal hooking not supported" end end end if prosody and set_config then local config_get = require "core.configmanager".get; local function load_config() local settings = config_get("*", "network_settings") or {}; return set_config(settings); end load_config(); prosody.events.add_handler("config-reloaded", load_config); end -- require "net.server" shall now forever return this, -- ie. server_select or server_event as chosen above. return server;