ceph/src/mds/Beacon.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2012 Red Hat
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15
  16 #ifndef BEACON_STATE_H
  17 #define BEACON_STATE_H
  18
  19 #include <boost/utility/string_view.hpp>
  20 #include <mutex>
  21 #include <thread>
  22
  23 #include "include/types.h"
  24 #include "include/Context.h"
  25 #include "msg/Dispatcher.h"
  26 #include "messages/MMDSBeacon.h"
  27
  28 class MonClient;
  29 class MMDSBeacon;
  30 class Message;
  31 class MDSRank;
  32
  33
  34 /**
  35  * One of these per MDS.  Handle beacon logic in this separate class so
  36  * that a busy MDS holding its own lock does not hold up sending beacon
  37  * messages to the mon and cause false lagginess.
  38  *
  39  * So that we can continue to operate while the MDS is holding its own lock,
  40  * we keep copies of the data needed to generate beacon messages.  The MDS is
  41  * responsible for calling Beacon::notify_* when things change.
  42  */
  43 class Beacon : public Dispatcher
  44 {
  45 public:
  46   using clock = ceph::coarse_mono_clock;
  47   using time = ceph::coarse_mono_time;
  48
  49   Beacon(CephContext *cct, MonClient *monc, boost::string_view name);
  50   ~Beacon() override;
  51
  52   void init(MDSMap const *mdsmap);
  53   void shutdown();
  54
  55   bool ms_can_fast_dispatch_any() const override { return true; }
  56   bool ms_can_fast_dispatch(const Message *m) const override;
  57   void ms_fast_dispatch(Message *m) override;
  58   bool ms_dispatch(Message *m) override;
  59   void ms_handle_connect(Connection *c) override {}
  60   bool ms_handle_reset(Connection *c) override {return false;}
  61   void ms_handle_remote_reset(Connection *c) override {}
  62   bool ms_handle_refused(Connection *c) override {return false;}
  63
  64   void notify_mdsmap(MDSMap const *mdsmap);
  65   void notify_health(MDSRank const *mds);
  66
  67   void handle_mds_beacon(MMDSBeacon *m);
  68   void send();
  69
  70   void set_want_state(MDSMap const *mdsmap, MDSMap::DaemonState const newstate);
  71   MDSMap::DaemonState get_want_state() const;
  72
  73   /**
  74    * Send a beacon, and block until the ack is received from the mon
  75    * or `duration` seconds pass, whichever happens sooner.  Useful
  76    * for emitting a last message on shutdown.
  77    */
  78   void send_and_wait(const double duration);
  79
  80   bool is_laggy();
  81   double last_cleared_laggy() const {
  82     std::unique_lock<std::mutex> lock(mutex);
  83     return std::chrono::duration<double>(clock::now()-last_laggy).count();
  84   }
  85
  86 private:
  87   void _notify_mdsmap(MDSMap const *mdsmap);
  88   void _send();
  89
  90   mutable std::mutex mutex;
  91   std::thread sender;
  92   std::condition_variable cvar;
  93   time last_send = time::min();
  94   double beacon_interval = 5.0;
  95   bool finished = false;
  96   MonClient*    monc;
  97
  98   // Items we duplicate from the MDS to have access under our own lock
  99   std::string name;
 100   version_t epoch = 0;
 101   CompatSet compat;
 102   mds_rank_t standby_for_rank = MDS_RANK_NONE;
 103   std::string standby_for_name;
 104   fs_cluster_id_t standby_for_fscid = FS_CLUSTER_ID_NONE;
 105   bool standby_replay = false;
 106   MDSMap::DaemonState want_state = MDSMap::STATE_BOOT;
 107
 108   // Internal beacon state
 109   version_t last_seq = 0; // last seq sent to monitor
 110   std::map<version_t,time>  seq_stamp;    // seq # -> time sent
 111   time last_acked_stamp = time::min();  // last time we sent a beacon that got acked
 112   time last_mon_reconnect = time::min();
 113   bool laggy = false;
 114   time last_laggy = time::min();
 115
 116   // Health status to be copied into each beacon message
 117   MDSHealth health;
 118 };
 119
 120 #endif // BEACON_STATE_H