hphp/runtime/server/host-health-monitor.cpp

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #include "hphp/runtime/server/host-health-monitor.h"
  18
  19 #include <folly/Singleton.h>
  20 #include <folly/system/ThreadName.h>
  21
  22 #include "hphp/runtime/base/init-fini-node.h"
  23 #include "hphp/runtime/ext/extension.h"
  24 #include "hphp/util/alloc-defs.h"
  25 #include "hphp/util/compatibility.h"
  26 #include "hphp/util/health-monitor-types.h"
  27 #include "hphp/util/logger.h"
  28
  29 namespace HPHP {
  30
  31 namespace {
  32 bool Enabled;
  33 int32_t UpdateFreq;
  34
  35 struct HostHealthMonitorExtension final : public Extension {
  36   HostHealthMonitorExtension() : Extension("hosthealthmonitor", "1.0") {}
  37
  38   void moduleLoad(const IniSetting::Map& ini, Hdf globalConfig) override {
  39     Config::Bind(Enabled, ini, globalConfig,
  40                  "HealthMonitor.EnableHealthMonitor", true);
  41     Config::Bind(UpdateFreq, ini, globalConfig,
  42                  "HealthMonitor.UpdateFreq", 1000 /* miliseconds */);
  43   }
  44 } s_host_health_monitor_extension;
  45
  46 folly::Singleton<HostHealthMonitor> s_health_monitor;
  47
  48 }
  49
  50 void HostHealthMonitor::addMetric(IHealthMonitorMetric* metric) {
  51   assertx(metric != nullptr);
  52   std::lock_guard<std::mutex> g(m_lock);
  53   m_metrics.push_back(metric);
  54 }
  55
  56 void IHealthMonitorMetric::registerSelf() {
  57   folly::Singleton<HostHealthMonitor>::try_get()->addMetric(this);
  58 }
  59
  60 void HostHealthMonitor::start() {
  61   if (!Enabled || !m_stopped) return;
  62   if (UpdateFreq < 10) UpdateFreq = 10;
  63   if (UpdateFreq > 10000) UpdateFreq = 10000;
  64
  65   m_monitor_thread = std::make_unique<std::thread>([] {
  66     folly::setThreadName("HostHealthMonitor");
  67     folly::Singleton<HostHealthMonitor>::try_get()->monitor();
  68   });
  69
  70   // Make sure the thread is gone after hphp_process_exit().  The node
  71   // is intentionally leaked.
  72   new InitFiniNode(
  73     [] { folly::Singleton<HostHealthMonitor>::try_get()->waitForEnd(); },
  74     InitFiniNode::When::ProcessExit
  75   );
  76 }
  77
  78 void HostHealthMonitor::stop() {
  79   notifyObservers(HealthLevel::Bold);
  80   std::unique_lock<std::mutex> guard(m_stopped_lock);
  81   m_stopped = true;
  82   m_condition.notify_one();
  83 }
  84
  85 void HostHealthMonitor::waitForEnd() {
  86   if (!m_stopped) stop();
  87   if (m_monitor_thread) {
  88     m_monitor_thread->join();
  89     m_monitor_thread.reset();
  90   }
  91 }
  92
  93 void HostHealthMonitor::monitor() {
  94   Logger::Info("Host health monitor starts working.");
  95   std::unique_lock<std::mutex> guard(m_stopped_lock);
  96   m_stopped = false;
  97
  98   std::chrono::milliseconds dura(UpdateFreq);
  99   while (!m_stopped) {
 100     HealthLevel newStatus = evaluate();
 101     notifyObservers(newStatus);
 102     m_condition.wait_for(guard, dura, [this] { return m_stopped; });
 103   }
 104   Logger::Info("Host health monitor exits.");
 105 }
 106
 107 HealthLevel HostHealthMonitor::evaluate() {
 108 #ifdef USE_JEMALLOC
 109   mallctl_epoch();
 110 #endif
 111   HealthLevel res = HealthLevel::Bold;
 112   std::lock_guard<std::mutex> g(m_lock);
 113   for (auto metric : m_metrics) {
 114     res = std::max(res, metric->evaluate());
 115   }
 116   return res;
 117 }
 118
 119 void HostHealthMonitor::notifyObservers(HealthLevel newStatus) {
 120   if (newStatus != m_status) {
 121     Logger::Warning("Health level (lower is better) changes from %d to %d.",
 122                     static_cast<int>(m_status), static_cast<int>(newStatus));
 123
 124     std::lock_guard<std::mutex> g(m_lock);
 125     for (auto observer : m_observers) {
 126       observer->notifyNewStatus(newStatus);
 127     }
 128     m_status = newStatus;
 129   }
 130 }
 131
 132 }