scaling_metrics.h

Go to the documentation of this file.

// BSD 3-Clause License
// Copyright (c) 2024, 🍀☀🌕🌥 🌊
// See the LICENSE file in the project root for full license information.
 
#pragma once
 
#include <chrono>
#include <cstddef>
#include <cstdint>
 
namespace kcenon::thread
{
    enum class scaling_direction
    {
        none,   
        up,     
        down    
    };
 
    enum class scaling_reason
    {
        queue_depth,        
        worker_utilization, 
        latency,            
        manual,             
        scheduled           
    };
 
    struct scaling_metrics_sample
    {
        std::chrono::steady_clock::time_point timestamp;
 
        std::size_t worker_count{0};
 
        std::size_t active_workers{0};
 
        std::size_t queue_depth{0};
 
        double utilization{0.0};
 
        double queue_depth_per_worker{0.0};
 
        double p95_latency_ms{0.0};
 
        std::uint64_t jobs_completed{0};
 
        std::uint64_t jobs_submitted{0};
 
        double throughput_per_second{0.0};
    };
 
    struct scaling_decision
    {
        scaling_direction direction{scaling_direction::none};
 
        scaling_reason reason{scaling_reason::queue_depth};
 
        std::size_t target_workers{0};
 
        std::string explanation;
 
        [[nodiscard]] auto should_scale() const -> bool
        {
            return direction != scaling_direction::none;
        }
    };
 
    struct autoscaling_stats
    {
        std::size_t scale_up_count{0};
 
        std::size_t scale_down_count{0};
 
        std::size_t decisions_evaluated{0};
 
        std::chrono::steady_clock::time_point last_scale_up;
 
        std::chrono::steady_clock::time_point last_scale_down;
 
        std::size_t peak_workers{0};
 
        std::size_t min_workers{0};
    };
 
} // namespace kcenon::thread