elector: hoist Elector data bits out into a new ElectionLogic class

Signed-off-by: Greg Farnum <gfarnum@redhat.com>

diff --git a/src/mon/Elector.cc b/src/mon/Elector.cc
index bee3b299f36a1897ced9432eee3e4b764163d824..41382f4a4c190b8f3116a9a3bb5e6a630be6f17f 100644 (file)
--- a/src/mon/Elector.cc
+++ b/src/mon/Elector.cc
@@ -24,7 +24,7 @@
 
 #define dout_subsys ceph_subsys_mon
 #undef dout_prefix
-#define dout_prefix _prefix(_dout, mon, epoch)
+#define dout_prefix _prefix(_dout, mon, logic.epoch)
 static ostream& _prefix(std::ostream *_dout, Monitor *mon, epoch_t epoch) {
   return *_dout << "mon." << mon->name << "@" << mon->rank
                << "(" << mon->get_state_name()
@@ -34,19 +34,19 @@ static ostream& _prefix(std::ostream *_dout, Monitor *mon, epoch_t epoch) {
 
 void Elector::init()
 {
-  epoch = mon->store->get(Monitor::MONITOR_NAME, "election_epoch");
-  if (!epoch) {
+  logic.epoch = mon->store->get(Monitor::MONITOR_NAME, "election_epoch");
+  if (!logic.epoch) {
     dout(1) << "init, first boot, initializing epoch at 1 " << dendl;
-    epoch = 1;
-  } else if (epoch % 2) {
-    dout(1) << "init, last seen epoch " << epoch
+    logic.epoch = 1;
+  } else if (logic.epoch % 2) {
+    dout(1) << "init, last seen epoch " << logic.epoch
            << ", mid-election, bumping" << dendl;
-    ++epoch;
+    ++logic.epoch;
     auto t(std::make_shared<MonitorDBStore::Transaction>());
-    t->put(Monitor::MONITOR_NAME, "election_epoch", epoch);
+    t->put(Monitor::MONITOR_NAME, "election_epoch", logic.epoch);
     mon->store->apply_transaction(t);
   } else {
-    dout(1) << "init, last seen epoch " << epoch << dendl;
+    dout(1) << "init, last seen epoch " << logic.epoch << dendl;
   }
 }
 
@@ -57,18 +57,19 @@ void Elector::shutdown()
 
 void Elector::bump_epoch(epoch_t e) 
 {
-  dout(10) << "bump_epoch " << epoch << " to " << e << dendl;
-  ceph_assert(epoch <= e);
-  epoch = e;
+  dout(10) << "bump_epoch " << logic.epoch << " to " << e << dendl;
+  ceph_assert(logic.epoch <= e);
+  logic.epoch = e;
   auto t(std::make_shared<MonitorDBStore::Transaction>());
-  t->put(Monitor::MONITOR_NAME, "election_epoch", epoch);
+  t->put(Monitor::MONITOR_NAME, "election_epoch", logic.epoch);
   mon->store->apply_transaction(t);
 
   mon->join_election();
 
   // clear up some state
-  electing_me = false;
-  acked_me.clear();
+  logic.electing_me = false;
+  logic.acked_me.clear();
+  peer_info.clear();
 }
 
 
@@ -80,12 +81,13 @@ void Elector::start()
   }
   dout(5) << "start -- can i be leader?" << dendl;
 
-  acked_me.clear();
+  logic.acked_me.clear();
+  peer_info.clear();
   init();
   
   // start by trying to elect me
-  if (epoch % 2 == 0) {
-    bump_epoch(epoch+1);  // odd == election cycle
+  if (logic.epoch % 2 == 0) {
+    bump_epoch(logic.epoch+1);  // odd == election cycle
   } else {
     // do a trivial db write just to ensure it is writeable.
     auto t(std::make_shared<MonitorDBStore::Transaction>());
@@ -93,18 +95,19 @@ void Elector::start()
     int r = mon->store->apply_transaction(t);
     ceph_assert(r >= 0);
   }
-  electing_me = true;
-  acked_me[mon->rank].cluster_features = CEPH_FEATURES_ALL;
-  acked_me[mon->rank].mon_release = ceph_release();
-  acked_me[mon->rank].mon_features = ceph::features::mon::get_supported();
-  mon->collect_metadata(&acked_me[mon->rank].metadata);
-  leader_acked = -1;
+  logic.electing_me = true;
+  logic.acked_me.insert(mon->rank);
+  peer_info[mon->rank].cluster_features = CEPH_FEATURES_ALL;
+  peer_info[mon->rank].mon_release = ceph_release();
+  peer_info[mon->rank].mon_features = ceph::features::mon::get_supported();
+  mon->collect_metadata(&peer_info[mon->rank].metadata);
+  logic.leader_acked = -1;
 
   // bcast to everyone else
   for (unsigned i=0; i<mon->monmap->size(); ++i) {
     if ((int)i == mon->rank) continue;
     MMonElection *m =
-      new MMonElection(MMonElection::OP_PROPOSE, epoch, mon->monmap);
+      new MMonElection(MMonElection::OP_PROPOSE, logic.epoch, mon->monmap);
     m->mon_features = ceph::features::mon::get_supported();
     m->mon_release = ceph_release();
     mon->send_mon_message(m, i);
@@ -117,15 +120,16 @@ void Elector::defer(int who)
 {
   dout(5) << "defer to " << who << dendl;
 
-  if (electing_me) {
+  if (logic.electing_me) {
     // drop out
-    acked_me.clear();
-    electing_me = false;
+    logic.acked_me.clear();
+    peer_info.clear();
+    logic.electing_me = false;
   }
 
   // ack them
-  leader_acked = who;
-  MMonElection *m = new MMonElection(MMonElection::OP_ACK, epoch, mon->monmap);
+  logic.leader_acked = who;
+  MMonElection *m = new MMonElection(MMonElection::OP_ACK, logic.epoch, mon->monmap);
   m->mon_features = ceph::features::mon::get_supported();
   m->mon_release = ceph_release();
   mon->collect_metadata(&m->metadata);
@@ -175,8 +179,8 @@ void Elector::expire()
   dout(5) << "election timer expired" << dendl;
   
   // did i win?
-  if (electing_me &&
-      acked_me.size() > (unsigned)(mon->monmap->size() / 2)) {
+  if (logic.electing_me &&
+      logic.acked_me.size() > (unsigned)(mon->monmap->size() / 2)) {
     // i win
     victory();
   } else {
@@ -191,16 +195,19 @@ void Elector::expire()
 
 void Elector::victory()
 {
-  leader_acked = -1;
-  electing_me = false;
+  logic.leader_acked = -1;
+  logic.electing_me = false;
 
   uint64_t cluster_features = CEPH_FEATURES_ALL;
   mon_feature_t mon_features = ceph::features::mon::get_supported();
   set<int> quorum;
   map<int,Metadata> metadata;
   ceph_release_t min_mon_release{ceph_release_t::unknown};
-  for (const auto& [id, info] : acked_me) {
+  for (auto id : logic.acked_me) {
     quorum.insert(id);
+    auto i = peer_info.find(id);
+    ceph_assert(i != peer_info.end());
+    auto& info = i->second;
     cluster_features &= info.cluster_features;
     mon_features &= info.mon_features;
     metadata[id] = info.metadata;
@@ -212,15 +219,15 @@ void Elector::victory()
 
   cancel_timer();
   
-  ceph_assert(epoch % 2 == 1);  // election
-  bump_epoch(epoch+1);     // is over!
+  ceph_assert(logic.epoch % 2 == 1);  // election
+  bump_epoch(logic.epoch+1);     // is over!
 
   // tell everyone!
   for (set<int>::iterator p = quorum.begin();
        p != quorum.end();
        ++p) {
     if (*p == mon->rank) continue;
-    MMonElection *m = new MMonElection(MMonElection::OP_VICTORY, epoch,
+    MMonElection *m = new MMonElection(MMonElection::OP_VICTORY, logic.epoch,
                                       mon->monmap);
     m->quorum = quorum;
     m->quorum_features = cluster_features;
@@ -231,7 +238,7 @@ void Elector::victory()
   }
 
   // tell monitor
-  mon->win_election(epoch, quorum,
+  mon->win_election(logic.epoch, quorum,
                     cluster_features, mon_features, min_mon_release,
                    metadata);
 }
@@ -274,11 +281,11 @@ void Elector::handle_propose(MonOpRequestRef op)
             << " without required mon_features " << missing
             << dendl;
     nak_old_peer(op);
-  } else if (m->epoch > epoch) {
+  } else if (m->epoch > logic.epoch) {
     bump_epoch(m->epoch);
-  } else if (m->epoch < epoch) {
+  } else if (m->epoch < logic.epoch) {
     // got an "old" propose,
-    if (epoch % 2 == 0 &&    // in a non-election cycle
+    if (logic.epoch % 2 == 0 &&    // in a non-election cycle
        mon->quorum.count(from) == 0) {  // from someone outside the quorum
       // a mon just started up, call a new election so they can rejoin!
       dout(5) << " got propose from old epoch, quorum is " << mon->quorum 
@@ -293,24 +300,24 @@ void Elector::handle_propose(MonOpRequestRef op)
 
   if (mon->rank < from) {
     // i would win over them.
-    if (leader_acked >= 0) {        // we already acked someone
-      ceph_assert(leader_acked < from);  // and they still win, of course
-      dout(5) << "no, we already acked " << leader_acked << dendl;
+    if (logic.leader_acked >= 0) {        // we already acked someone
+      ceph_assert(logic.leader_acked < from);  // and they still win, of course
+      dout(5) << "no, we already acked " << logic.leader_acked << dendl;
     } else {
       // wait, i should win!
-      if (!electing_me) {
+      if (!logic.electing_me) {
        mon->start_election();
       }
     }
   } else {
     // they would win over me
-    if (leader_acked < 0 ||      // haven't acked anyone yet, or
-       leader_acked > from ||   // they would win over who you did ack, or
-       leader_acked == from) {  // this is the guy we're already deferring to
+    if (logic.leader_acked < 0 ||      // haven't acked anyone yet, or
+       logic.leader_acked > from ||   // they would win over who you did ack, or
+       logic.leader_acked == from) {  // this is the guy we're already deferring to
       defer(from);
     } else {
       // ignore them!
-      dout(5) << "no, we already acked " << leader_acked << dendl;
+      dout(5) << "no, we already acked " << logic.leader_acked << dendl;
     }
   }
 }
@@ -323,13 +330,13 @@ void Elector::handle_ack(MonOpRequestRef op)
   int from = m->get_source().num();
 
   ceph_assert(m->epoch % 2 == 1); // election
-  if (m->epoch > epoch) {
+  if (m->epoch > logic.epoch) {
     dout(5) << "woah, that's a newer epoch, i must have rebooted.  bumping and re-starting!" << dendl;
     bump_epoch(m->epoch);
     start();
     return;
   }
-  ceph_assert(m->epoch == epoch);
+  ceph_assert(m->epoch == logic.epoch);
   uint64_t required_features = mon->get_required_features();
   if ((required_features ^ m->get_connection()->get_features()) &
       required_features) {
@@ -347,17 +354,19 @@ void Elector::handle_ack(MonOpRequestRef op)
     return;
   }
 
-  if (electing_me) {
+  if (logic.electing_me) {
     // thanks
-    acked_me[from].cluster_features = m->get_connection()->get_features();
-    acked_me[from].mon_features = m->mon_features;
-    acked_me[from].mon_release = m->mon_release;
-    acked_me[from].metadata = m->metadata;
+    peer_info[from].cluster_features = m->get_connection()->get_features();
+    peer_info[from].mon_features = m->mon_features;
+    peer_info[from].mon_release = m->mon_release;
+    peer_info[from].metadata = m->metadata;
     dout(5) << " so far i have {";
-    for (map<int, elector_info_t>::const_iterator p = acked_me.begin();
-         p != acked_me.end();
-         ++p) {
-      if (p != acked_me.begin())
+    for (auto q = logic.acked_me.begin();
+         q != logic.acked_me.end();
+         ++q) {
+      auto p = peer_info.find(*q);
+      ceph_assert(p != peer_info.end());
+      if (q != logic.acked_me.begin())
         *_dout << ",";
       *_dout << " mon." << p->first << ":"
              << " features " << p->second.cluster_features
@@ -366,13 +375,13 @@ void Elector::handle_ack(MonOpRequestRef op)
     *_dout << " }" << dendl;
 
     // is that _everyone_?
-    if (acked_me.size() == mon->monmap->size()) {
+    if (logic.acked_me.size() == mon->monmap->size()) {
       // if yes, shortcut to election finish
       victory();
     }
   } else {
     // ignore, i'm deferring already.
-    ceph_assert(leader_acked >= 0);
+    ceph_assert(logic.leader_acked >= 0);
   }
 }
 
@@ -390,10 +399,10 @@ void Elector::handle_victory(MonOpRequestRef op)
   ceph_assert(from < mon->rank);
   ceph_assert(m->epoch % 2 == 0);  
 
-  leader_acked = -1;
+  logic.leader_acked = -1;
 
   // i should have seen this election if i'm getting the victory.
-  if (m->epoch != epoch + 1) { 
+  if (m->epoch != logic.epoch + 1) { 
     dout(5) << "woah, that's a funny epoch, i must have rebooted.  bumping and re-starting!" << dendl;
     bump_epoch(m->epoch);
     start();
@@ -403,7 +412,7 @@ void Elector::handle_victory(MonOpRequestRef op)
   bump_epoch(m->epoch);
 
   // they win
-  mon->lose_election(epoch, m->quorum, from,
+  mon->lose_election(logic.epoch, m->quorum, from,
                      m->quorum_features, m->mon_features, m->mon_release);
 
   // cancel my timer
@@ -531,7 +540,7 @@ void Elector::dispatch(MonOpRequestRef op)
        return;
       }
 
-      if (em->epoch < epoch) {
+      if (em->epoch < logic.epoch) {
        dout(5) << "old epoch, dropping" << dendl;
        break;
       }

diff --git a/src/mon/Elector.h b/src/mon/Elector.h
index e83e434afac1352679e400738480ed0f2082e3a6..2b4b8020800a075a399b9790dd6628ea9e8cddc3 100644 (file)
--- a/src/mon/Elector.h
+++ b/src/mon/Elector.h
@@ -25,6 +25,20 @@
 
 class Monitor;
 
+class Elector;
+
+class ElectionLogic {
+public:
+  Elector *elector;
+  epoch_t epoch;
+  bool electing_me;
+  set<int> acked_me;
+  int leader_acked;
+
+  ElectionLogic(Elector *e) : elector(e), epoch(0),
+                             electing_me(false), leader_acked(-1) {}
+};
+
 /**
  * This class is responsible for maintaining the local state when electing
  * a new Leader. We may win or we may lose. If we win, it means we became the
@@ -36,6 +50,7 @@ class Elector {
    * @{
    */
  private:
+  ElectionLogic logic;
    /**
    * @defgroup Elector_h_internal_types Internal Types
    * @{
@@ -94,7 +109,7 @@ class Elector {
    * @remarks if its value is odd, we're electing; if it's even, then we're
    *         stable.
    */
-  epoch_t epoch;
+  //epoch_t epoch;
 
   /**
    * Indicates if we are participating in the quorum.
@@ -120,14 +135,14 @@ class Elector {
    * to be elected if we think we might have a chance (i.e., the other guy's
    * rank is lower than ours).
    */
-  bool     electing_me;
+  //  bool     electing_me;
   /**
    * Set containing all those that acked our proposal to become the Leader.
    *
    * If we are acked by everyone in the MonMap, we will declare
    * victory.  Also note each peer's feature set.
    */
-  map<int, elector_info_t> acked_me;
+  map<int, elector_info_t> peer_info;
   /**
    * @}
    */
@@ -138,7 +153,7 @@ class Elector {
   /**
    * Indicates who we have acked
    */
-  int      leader_acked;
+  //  int          leader_acked;
   /**
    * @}
    */
@@ -327,11 +342,9 @@ class Elector {
    *
    * @param m A Monitor instance
    */
-  explicit Elector(Monitor *m) : mon(m),
-                       epoch(0),
-                       participating(true),
-                       electing_me(false),
-                       leader_acked(-1) { }
+  explicit Elector(Monitor *m) : logic(this),
+                       mon(m),
+                                participating(true) {}
 
   /**
    * Initiate the Elector class.
@@ -356,7 +369,7 @@ class Elector {
    *
    * @returns Our current epoch number
    */
-  epoch_t get_epoch() { return epoch; }
+  epoch_t get_epoch() { return logic.epoch; }
 
   /**
    * advance_epoch
@@ -364,7 +377,7 @@ class Elector {
    * increase election epoch by 1
    */
   void advance_epoch() {
-    bump_epoch(epoch + 1);
+    bump_epoch(logic.epoch + 1);
   }
 
   /**