memgraph/src/http_handlers/metrics.hpp
2023-11-22 13:05:02 +00:00

213 lines
8.1 KiB
C++

// Copyright 2023 Memgraph Ltd.
//
// Use of this software is governed by the Business Source License
// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
// License, and you may not use this file except in compliance with the Business Source License.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0, included in the file
// licenses/APL.txt.
#pragma once
#include <atomic>
#include <tuple>
#include <vector>
#include <spdlog/spdlog.h>
#include <boost/beast/http.hpp>
#include <boost/beast/version.hpp>
#include <json/json.hpp>
#include <utils/event_counter.hpp>
#include <utils/event_gauge.hpp>
#include "storage/v2/storage.hpp"
#include "utils/event_histogram.hpp"
namespace memgraph::http {
struct MetricsResponse {
uint64_t vertex_count;
uint64_t edge_count;
double average_degree;
uint64_t memory_usage;
uint64_t disk_usage;
// Storage of all the counter values throughout the system
// e.g. number of active transactions
std::vector<std::tuple<std::string, std::string, uint64_t>> event_counters{};
// Storage of all the current values throughout the system
std::vector<std::tuple<std::string, std::string, uint64_t>> event_gauges{};
// Storage of all the percentile values across the histograms in the system
// e.g. query latency percentiles, snapshot recovery duration percentiles, etc.
std::vector<std::tuple<std::string, std::string, uint64_t>> event_histograms{};
};
class MetricsService {
public:
explicit MetricsService(storage::Storage *storage) : db_(storage) {}
nlohmann::json GetMetricsJSON() {
auto response = GetMetrics();
return AsJson(response);
}
private:
storage::Storage *const db_;
MetricsResponse GetMetrics() {
auto info = db_->GetBaseInfo();
return MetricsResponse{.vertex_count = info.vertex_count,
.edge_count = info.edge_count,
.average_degree = info.average_degree,
.memory_usage = info.memory_res,
.disk_usage = info.disk_usage,
.event_counters = GetEventCounters(),
.event_gauges = GetEventGauges(),
.event_histograms = GetEventHistograms()};
}
nlohmann::json AsJson(MetricsResponse response) {
auto metrics_response = nlohmann::json();
const auto *general_type = "General";
metrics_response[general_type]["vertex_count"] = response.vertex_count;
metrics_response[general_type]["edge_count"] = response.edge_count;
metrics_response[general_type]["average_degree"] = response.average_degree;
metrics_response[general_type]["memory_usage"] = response.memory_usage;
metrics_response[general_type]["disk_usage"] = response.disk_usage;
for (const auto &[name, type, value] : response.event_counters) {
metrics_response[type][name] = value;
}
for (const auto &[name, type, value] : response.event_gauges) {
metrics_response[type][name] = value;
}
for (const auto &[name, type, value] : response.event_histograms) {
metrics_response[type][name] = value;
}
return metrics_response;
}
inline static std::vector<std::tuple<std::string, std::string, uint64_t>> GetEventCounters() {
// NOLINTNEXTLINE(cppcoreguidelines-init-variables)
std::vector<std::tuple<std::string, std::string, uint64_t>> event_counters{};
event_counters.reserve(memgraph::metrics::CounterEnd());
for (auto i = 0; i < memgraph::metrics::CounterEnd(); i++) {
event_counters.emplace_back(memgraph::metrics::GetCounterName(i), memgraph::metrics::GetCounterType(i),
memgraph::metrics::global_counters[i].load(std::memory_order_acquire));
}
return event_counters;
}
inline static std::vector<std::tuple<std::string, std::string, uint64_t>> GetEventGauges() {
// NOLINTNEXTLINE(cppcoreguidelines-init-variables)
std::vector<std::tuple<std::string, std::string, uint64_t>> event_gauges{};
event_gauges.reserve(memgraph::metrics::GaugeEnd());
for (auto i = 0; i < memgraph::metrics::GaugeEnd(); i++) {
event_gauges.emplace_back(memgraph::metrics::GetGaugeName(i), memgraph::metrics::GetGaugeType(i),
memgraph::metrics::global_gauges[i].load(std::memory_order_acquire));
}
return event_gauges;
}
inline static std::vector<std::tuple<std::string, std::string, uint64_t>> GetEventHistograms() {
// NOLINTNEXTLINE(cppcoreguidelines-init-variables)
std::vector<std::tuple<std::string, std::string, uint64_t>> event_histograms{};
for (auto i = 0; i < memgraph::metrics::HistogramEnd(); i++) {
const auto *name = memgraph::metrics::GetHistogramName(i);
auto &histogram = memgraph::metrics::global_histograms[i];
for (auto &[percentile, value] : histogram.YieldPercentiles()) {
auto metric_name = std::string(name) + "_" + std::to_string(percentile) + "p";
event_histograms.emplace_back(metric_name, memgraph::metrics::GetHistogramType(i), value);
}
}
return event_histograms;
}
};
// TODO: Should this be inside Database?
// Raw pointer could be dangerous
class MetricsRequestHandler final {
public:
explicit MetricsRequestHandler(storage::Storage *storage) : service_(storage) {
spdlog::info("Basic request handler started!");
}
MetricsRequestHandler(const MetricsRequestHandler &) = delete;
MetricsRequestHandler(MetricsRequestHandler &&) = delete;
MetricsRequestHandler &operator=(const MetricsRequestHandler &) = delete;
MetricsRequestHandler &operator=(MetricsRequestHandler &&) = delete;
~MetricsRequestHandler() = default;
template <class Body, class Allocator>
// NOLINTNEXTLINE(misc-unused-parameters)
void HandleRequest(boost::beast::http::request<Body, boost::beast::http::basic_fields<Allocator>> &&req,
std::function<void(boost::beast::http::response<boost::beast::http::string_body>)> &&send) {
auto response_json = nlohmann::json();
// Returns a bad request response
auto const bad_request = [&req, &response_json](const auto why) {
response_json["error"] = std::string(why);
// NOLINTNEXTLINE(cppcoreguidelines-init-variables)
boost::beast::http::response<boost::beast::http::string_body> res{boost::beast::http::status::bad_request,
req.version()};
res.set(boost::beast::http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(boost::beast::http::field::content_type, "application/json");
res.keep_alive(req.keep_alive());
res.body() = response_json.dump();
res.prepare_payload();
return res;
};
// Make sure we can handle the method
if (req.method() != boost::beast::http::verb::get) {
return send(bad_request("Unknown HTTP-method"));
}
// Request path must be absolute and not contain "..".
if (req.target().empty() || req.target()[0] != '/' || req.target().find("..") != boost::beast::string_view::npos) {
return send(bad_request("Illegal request-target"));
}
// NOLINTNEXTLINE(cppcoreguidelines-init-variables)
boost::beast::http::string_body::value_type body;
auto service_response = service_.GetMetricsJSON();
body.append(service_response.dump());
// Cache the size since we need it after the move
const auto size = body.size();
// Respond to GET request
// NOLINTNEXTLINE(cppcoreguidelines-init-variables)
boost::beast::http::response<boost::beast::http::string_body> res{
std::piecewise_construct, std::make_tuple(std::move(body)),
std::make_tuple(boost::beast::http::status::ok, req.version())};
res.set(boost::beast::http::field::server, BOOST_BEAST_VERSION_STRING);
res.set(boost::beast::http::field::content_type, "application/json");
res.content_length(size);
res.keep_alive(req.keep_alive());
return send(std::move(res));
}
private:
MetricsService service_;
};
} // namespace memgraph::http