Metric.cpp

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/*
 * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "Metric.h"
#include "Config.h"
#include "DeadlineTimer.h"
#include "IoContext.h"
#include "Log.h"
#include "Util.h"
#include <boost/asio/ip/tcp.hpp>
#include <span>
 
void Metric::Initialize(std::string const& realmName, Trinity::Asio::IoContext& ioContext, std::function<void()> overallStatusLogger)
{
    _dataStream = std::make_unique<boost::asio::ip::tcp::iostream>();
    _realmName = FormatInfluxDBTagValue(realmName);
    _batchTimer = std::make_unique<Trinity::Asio::DeadlineTimer>(ioContext);
    _overallStatusTimer = std::make_unique<Trinity::Asio::DeadlineTimer>(ioContext);
    _overallStatusLogger = std::move(overallStatusLogger);
    LoadFromConfigs();
}
 
bool Metric::Connect()
{
    GetDataStream().connect(_hostname, _port);
    if (boost::system::error_code const& error = GetDataStream().error())
    {
        TC_LOG_ERROR("metric", "Error connecting to '{}:{}', disabling Metric. Error message : {}",
            _hostname, _port, error.message());
        _enabled = false;
        return false;
    }
    GetDataStream().clear();
    return true;
}
 
void Metric::LoadFromConfigs()
{
    bool previousValue = _enabled;
    _enabled = sConfigMgr->GetBoolDefault("Metric.Enable", false);
    _updateInterval = sConfigMgr->GetIntDefault("Metric.Interval", 1);
    if (_updateInterval < 1)
    {
        TC_LOG_ERROR("metric", "'Metric.Interval' config set to {}, overriding to 1.", _updateInterval);
        _updateInterval = 1;
    }
 
    _overallStatusTimerInterval = sConfigMgr->GetIntDefault("Metric.OverallStatusInterval", 1);
    if (_overallStatusTimerInterval < 1)
    {
        TC_LOG_ERROR("metric", "'Metric.OverallStatusInterval' config set to {}, overriding to 1.", _overallStatusTimerInterval);
        _overallStatusTimerInterval = 1;
    }
 
    _thresholds.clear();
    std::vector<std::string> thresholdSettings = sConfigMgr->GetKeysByString("Metric.Threshold.");
    for (std::string& thresholdSetting : thresholdSettings)
    {
        int64 thresholdValue = sConfigMgr->GetIntDefault(thresholdSetting, 0);
        std::string thresholdName = thresholdSetting.substr(strlen("Metric.Threshold."));
        _thresholds.emplace(std::move(thresholdName), thresholdValue);
    }
 
    // Schedule a send at this point only if the config changed from Disabled to Enabled.
    // Cancel any scheduled operation if the config changed from Enabled to Disabled.
    if (_enabled && !previousValue)
    {
        std::string connectionInfo = sConfigMgr->GetStringDefault("Metric.ConnectionInfo", "");
        if (connectionInfo.empty())
        {
            TC_LOG_ERROR("metric", "'Metric.ConnectionInfo' not specified in configuration file.");
            return;
        }
 
        std::vector<std::string_view> tokens = Trinity::Tokenize(connectionInfo, ';', true);
        if (tokens.size() != 3)
        {
            TC_LOG_ERROR("metric", "'Metric.ConnectionInfo' specified with wrong format in configuration file.");
            return;
        }
 
        _hostname.assign(tokens[0]);
        _port.assign(tokens[1]);
        _databaseName.assign(tokens[2]);
        Connect();
 
        ScheduleSend();
        ScheduleOverallStatusLog();
    }
}
 
void Metric::Update()
{
    if (_overallStatusTimerTriggered)
    {
        _overallStatusTimerTriggered = false;
        _overallStatusLogger();
    }
}
 
bool Metric::ShouldLog(std::string_view category, int64 value) const
{
    auto threshold = _thresholds.find(category);
    if (threshold == _thresholds.end())
        return false;
    return value >= threshold->second;
}
 
void Metric::LogEvent(std::string_view category, std::string_view title, std::string description)
{
    MetricData* data = new MetricData
    {
        .Category = std::string(category),
        .Timestamp = std::chrono::system_clock::now(),
        .Type = METRIC_DATA_EVENT,
        .Title = std::string(title),
        .ValueOrEventText = std::move(description)
    };
 
    _queuedData.Enqueue(data);
}
 
void Metric::SendBatch()
{
    using namespace std::chrono;
 
    std::stringstream batchedData;
    MetricData* data;
    bool firstLoop = true;
    while (_queuedData.Dequeue(data))
    {
        if (!firstLoop)
            batchedData << "\n";
 
        batchedData << data->Category;
        if (!_realmName.empty())
            batchedData << ",realm=" << _realmName;
 
        auto tags = [](MetricTags const& tags) -> std::span<MetricTag const>
        {
            switch (tags.index())
            {
                case 1: return std::get<1>(tags);
                case 2: return std::get<2>(tags);
                default:
                    break;
            }
            return {};
        }(data->Tags);
 
        for (auto const& [tagName, tagValue] : tags)
            if (!tagName.empty())
                batchedData << "," << tagName << "=" << FormatInfluxDBTagValue(tagValue);
 
        batchedData << " ";
 
        switch (data->Type)
        {
            case METRIC_DATA_VALUE:
                batchedData << "value=" << data->ValueOrEventText;
                break;
            case METRIC_DATA_EVENT:
                batchedData << "title=\"" << data->Title << "\",text=\"" << data->ValueOrEventText << "\"";
                break;
        }
 
        batchedData << " ";
 
        batchedData << duration_cast<nanoseconds>(data->Timestamp.time_since_epoch()).count();
 
        firstLoop = false;
        delete data;
    }
 
    // Check if there's any data to send
    std::streamoff batchedDataSize = batchedData.tellp();
    if (batchedDataSize <= 0)
    {
        ScheduleSend();
        return;
    }
 
    if (!GetDataStream().good() && !Connect())
        return;
 
    GetDataStream() << "POST " << "/write?db=" << _databaseName << " HTTP/1.1\r\n";
    GetDataStream() << "Host: " << _hostname << ":" << _port << "\r\n";
    GetDataStream() << "Accept: */*\r\n";
    GetDataStream() << "Content-Type: application/octet-stream\r\n";
    GetDataStream() << "Content-Transfer-Encoding: binary\r\n";
 
    GetDataStream() << "Content-Length: " << batchedDataSize << "\r\n\r\n";
    GetDataStream() << batchedData.rdbuf();
 
    std::string http_version;
    GetDataStream() >> http_version;
    unsigned int status_code = 0;
    GetDataStream() >> status_code;
    if (status_code != 204)
    {
        TC_LOG_ERROR("metric", "Error sending data, returned HTTP code: {}", status_code);
    }
 
    // Read and ignore the status description
    std::string status_description;
    std::getline(GetDataStream(), status_description);
    // Read headers
    std::string header;
    while (std::getline(GetDataStream(), header) && header != "\r")
        if (header == "Connection: close\r")
            GetDataStream().close();
 
    ScheduleSend();
}
 
void Metric::ScheduleSend()
{
    if (_enabled)
    {
        _batchTimer->expires_after(std::chrono::seconds(_updateInterval));
        _batchTimer->async_wait([this](boost::system::error_code const&){ SendBatch(); });
    }
    else
    {
        GetDataStream().close();
        MetricData* data;
        // Clear the queue
        while (_queuedData.Dequeue(data))
            delete data;
    }
}
 
void Metric::Unload()
{
    // Send what's queued only if IoContext is stopped (so only on shutdown)
    if (_enabled && Trinity::Asio::get_io_context(*_batchTimer).stopped())
    {
        _enabled = false;
        SendBatch();
    }
 
    _batchTimer->cancel();
    _overallStatusTimer->cancel();
}
 
void Metric::ScheduleOverallStatusLog()
{
    if (_enabled)
    {
        _overallStatusTimer->expires_after(std::chrono::seconds(_overallStatusTimerInterval));
        _overallStatusTimer->async_wait([this](const boost::system::error_code&)
        {
            _overallStatusTimerTriggered = true;
            ScheduleOverallStatusLog();
        });
    }
}
 
std::string Metric::FormatInfluxDBValue(bool value)
{
    return std::string(1, value ? 't' : 'f');
}
 
template<class T> requires std::integral<T> && (!std::same_as<T, bool>)
std::string Metric::FormatInfluxDBValue(T value)
{
    std::string result = std::to_string(value);
    result += 'i';
    return result;
}
 
std::string Metric::FormatInfluxDBValue(std::string const& value)
{
    std::string result = StringReplaceAll(value, "\"", "\\\"");
    result.insert(result.begin(), '"');
    result.append(1, '"');
    return result;
}
 
std::string Metric::FormatInfluxDBValue(char const* value)
{
    return FormatInfluxDBValue(std::string(value));
}
 
std::string Metric::FormatInfluxDBValue(double value)
{
    return std::to_string(value);
}
 
std::string Metric::FormatInfluxDBValue(float value)
{
    return FormatInfluxDBValue(double(value));
}
 
std::string Metric::FormatInfluxDBTagValue(std::string const& value)
{
    // ToDo: should handle '=' and ',' characters too
    return StringReplaceAll(value, " ", "\\ ");
}
 
std::string Metric::FormatInfluxDBValue(std::chrono::nanoseconds value)
{
    return FormatInfluxDBValue(std::chrono::duration_cast<Milliseconds>(value).count());
}
 
Metric::Metric()
{
}
 
Metric::~Metric()
{
}
 
Metric* Metric::instance()
{
    static Metric instance;
    return &instance;
}
 
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(int8);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(uint8);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(int16);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(uint16);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(int32);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(uint32);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(int64);
template TC_COMMON_API std::string Metric::FormatInfluxDBValue(uint64);