ceph/src/mds/MDBalancer.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) 2004-2006 Sage Weil <sage@newdream.net>
   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
  17 #ifndef CEPH_MDBALANCER_H
  18 #define CEPH_MDBALANCER_H
  19
  20 #include <list>
  21 #include <map>
  22 using std::list;
  23 using std::map;
  24
  25 #include "include/types.h"
  26 #include "common/Clock.h"
  27 #include "common/Cond.h"
  28
  29 class MDSMap;
  30 class MDSRank;
  31 class Message;
  32 class MHeartbeat;
  33 class CInode;
  34 class CDir;
  35 class Messenger;
  36 class MonClient;
  37
  38 class MDBalancer {
  39   friend class C_Bal_SendHeartbeat;
  40 public:
  41   MDBalancer(MDSRank *m, Messenger *msgr, MonClient *monc);
  42
  43   void handle_conf_change(const struct md_config_t *conf,
  44                           const std::set <std::string> &changed,
  45                           const MDSMap &mds_map);
  46
  47   int proc_message(Message *m);
  48
  49   /**
  50    * Regularly called upkeep function.
  51    *
  52    * Sends MHeartbeat messages to the mons.
  53    */
  54   void tick();
  55
  56   void subtract_export(CDir *ex, utime_t now);
  57   void add_import(CDir *im, utime_t now);
  58   void adjust_pop_for_rename(CDir *pdir, CDir *dir, utime_t now, bool inc);
  59
  60   void hit_inode(const utime_t& now, CInode *in, int type, int who=-1);
  61   void hit_dir(const utime_t& now, CDir *dir, int type, int who=-1, double amount=1.0);
  62
  63   void queue_split(const CDir *dir, bool fast);
  64   void queue_merge(CDir *dir);
  65
  66   /**
  67    * Based on size and configuration, decide whether to issue a queue_split
  68    * or queue_merge for this CDir.
  69    *
  70    * \param hot whether the directory's temperature is enough to split it
  71    */
  72   void maybe_fragment(CDir *dir, bool hot);
  73
  74   void handle_mds_failure(mds_rank_t who);
  75
  76   int dump_loads(Formatter *f);
  77
  78 private:
  79   bool bal_fragment_dirs;
  80   int64_t bal_fragment_interval;
  81
  82   typedef struct {
  83     std::map<mds_rank_t, double> targets;
  84     std::map<mds_rank_t, double> imported;
  85     std::map<mds_rank_t, double> exported;
  86   } balance_state_t;
  87
  88   //set up the rebalancing targets for export and do one if the
  89   //MDSMap is up to date
  90   void prep_rebalance(int beat);
  91   int mantle_prep_rebalance();
  92
  93   void handle_export_pins(void);
  94
  95   mds_load_t get_load(utime_t now);
  96   int localize_balancer();
  97   void send_heartbeat();
  98   void handle_heartbeat(MHeartbeat *m);
  99   void find_exports(CDir *dir,
 100                     double amount,
 101                     list<CDir*>& exports,
 102                     double& have,
 103                     set<CDir*>& already_exporting);
 104
 105   double try_match(balance_state_t &state,
 106                    mds_rank_t ex, double& maxex,
 107                    mds_rank_t im, double& maxim);
 108
 109   double get_maxim(balance_state_t &state, mds_rank_t im) {
 110     return target_load - mds_meta_load[im] - state.imported[im];
 111   }
 112   double get_maxex(balance_state_t &state, mds_rank_t ex) {
 113     return mds_meta_load[ex] - target_load - state.exported[ex];
 114   }
 115
 116   /**
 117    * Try to rebalance.
 118    *
 119    * Check if the monitor has recorded the current export targets;
 120    * if it has then do the actual export. Otherwise send off our
 121    * export targets message again.
 122    */
 123   void try_rebalance(balance_state_t& state);
 124
 125   MDSRank *mds;
 126   Messenger *messenger;
 127   MonClient *mon_client;
 128   int beat_epoch = 0;
 129
 130   string bal_code;
 131   string bal_version;
 132
 133   utime_t last_heartbeat;
 134   utime_t last_sample;
 135   utime_t rebalance_time; //ensure a consistent view of load for rebalance
 136
 137   utime_t last_get_load;
 138   uint64_t last_num_requests = 0;
 139   uint64_t last_cpu_time = 0;
 140
 141   // Dirfrags which are marked to be passed on to MDCache::[split|merge]_dir
 142   // just as soon as a delayed context comes back and triggers it.
 143   // These sets just prevent us from spawning extra timer contexts for
 144   // dirfrags that already have one in flight.
 145   set<dirfrag_t>   split_pending, merge_pending;
 146
 147   // per-epoch scatter/gathered info
 148   map<mds_rank_t, mds_load_t>  mds_load;
 149   map<mds_rank_t, double>       mds_meta_load;
 150   map<mds_rank_t, map<mds_rank_t, float> > mds_import_map;
 151   map<mds_rank_t, int> mds_last_epoch_under_map;
 152
 153   // per-epoch state
 154   double my_load = 0;
 155   double target_load = 0;
 156 };
 157
 158 #endif