LoadStatistics.h

Go to the documentation of this file.

/*
 * Copyright (C) 2007-2015 Hypertable, Inc.
 *
 * This file is part of Hypertable.
 *
 * Hypertable 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; version 3 of the
 * License.
 *
 * Hypertable 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#ifndef Hypertable_RangeServer_LoadStatistics_h
#define Hypertable_RangeServer_LoadStatistics_h

#include <Common/Logger.h>
#include <Common/Time.h>

#include <chrono>
#include <memory>
#include <mutex>

namespace Hypertable {

  class LoadStatistics {
  public:

    struct Bundle {
      void clear() {
        scan_count = update_count = sync_count = 0;
        cells_scanned = cells_returned = cached_cells_returned = 0;
        bytes_scanned = bytes_returned = cached_bytes_returned = 0;
        update_count = update_cells = 0;
        update_bytes = 0;
        scan_mbps = 0.0;
        update_mbps = 0.0;
        period_millis = 0;
        compactions_major = compactions_minor =
          compactions_merging = compactions_gc = 0;
      }
      uint32_t scan_count;     
      uint32_t cells_scanned;  
      uint32_t cached_cells_returned;  
      uint32_t cells_returned; 
      uint64_t bytes_scanned;  
      uint64_t cached_bytes_returned;  
      uint64_t bytes_returned; 
      uint32_t update_count;   
      uint32_t update_cells;   
      uint64_t update_bytes;   
      double scan_mbps;        
      double update_mbps;      
      uint32_t sync_count;     
      int64_t period_millis;   
      int32_t compactions_major;
      int32_t compactions_minor;
      int32_t compactions_merging;
      int32_t compactions_gc;
    };

    LoadStatistics(int64_t compute_period) : m_compute_period(compute_period) {
      m_start_time = std::chrono::steady_clock::now();
      m_running.clear();
      m_computed.clear();
    }

    void lock() { m_mutex.lock(); }

    void unlock() { m_mutex.unlock(); }

    void add_scan_data(uint32_t count, uint32_t cells_scanned,
                       uint32_t cells_returned, uint64_t bytes_scanned,
                       uint64_t bytes_returned) {
      m_running.scan_count += count;
      m_running.cells_scanned += cells_scanned;
      m_running.cells_returned += cells_returned;
      m_running.bytes_scanned += bytes_scanned;
      m_running.bytes_returned += bytes_returned;
    }

    void add_cached_scan_data(uint32_t count, uint32_t cached_cells_returned,
                              uint64_t cached_bytes_returned) {
      m_running.scan_count += count;
      m_running.cached_cells_returned += cached_cells_returned;
      m_running.cached_bytes_returned += cached_bytes_returned;
    }

    void add_update_data(uint32_t count, uint32_t cells, uint64_t total_bytes, uint32_t syncs) {
      m_running.update_count += count;
      m_running.update_cells += cells;
      m_running.update_bytes += total_bytes;
      m_running.sync_count += syncs;
    }

    void increment_compactions_major() {
      std::lock_guard<std::mutex> lock(m_mutex);
      m_running.compactions_major++;
    }

    void increment_compactions_minor() {
      std::lock_guard<std::mutex> lock(m_mutex);
      m_running.compactions_minor++;
    }

    void increment_compactions_merging() {
      std::lock_guard<std::mutex> lock(m_mutex);
      m_running.compactions_merging++;
    }

    void increment_compactions_gc() {
      std::lock_guard<std::mutex> lock(m_mutex);
      m_running.compactions_gc++;
    }

    void recompute(Bundle *stats=0) {
      std::lock_guard<std::mutex> lock(m_mutex);
      auto now = std::chrono::steady_clock::now();
      int64_t period_millis = std::chrono::duration_cast<std::chrono::milliseconds>(now - m_start_time).count();
      if (period_millis >= m_compute_period) {
        m_computed = m_running;
        m_computed.period_millis = period_millis;
        double time_diff = (double)m_computed.period_millis * 1000.0;
        if (time_diff) {
          m_computed.scan_mbps =
            (double)m_computed.bytes_scanned / time_diff;
          m_computed.update_mbps =
            (double)m_computed.update_bytes / time_diff;
        }
        else {
          HT_ERROR("mbps calculation over zero time range");
          m_computed.scan_mbps = 0.0;
          m_computed.update_mbps = 0.0;
        }
        m_start_time = now;
        m_running.clear();

        HT_INFOF("scans=(%u %u %llu %f) updates=(%u %u %llu %f %u)",
                 m_computed.scan_count, m_computed.cells_scanned,
                 (Llu)m_computed.bytes_scanned, m_computed.scan_mbps,
                 m_computed.update_count, m_computed.update_cells,
                 (Llu)m_computed.update_bytes, m_computed.update_mbps,
                 m_computed.sync_count);
      }
      if (stats)
        *stats = m_computed;
    }

    void get(Bundle *stats) {
      std::lock_guard<std::mutex> lock(m_mutex);
      *stats = m_computed;
    }

    std::mutex m_mutex;
    
    // Time period over which statistics are to be computed
    int64_t m_compute_period;

    // Starting time of current time perioed
    std::chrono::steady_clock::time_point m_start_time;

    // Holds statistics currently being gathered
    Bundle m_running;

    // Computed statistics for last completed time period
    Bundle m_computed;
  };

  typedef std::shared_ptr<LoadStatistics> LoadStatisticsPtr;

}

#endif // Hypertable_RangeServer_LoadStatistics_h