mon: reduce CPU and memory manager pressure of pg health check

src/mon/PGMap.cc

@@ -914,7 +914,7 @@ void PGMap::dump_osd_sum_stats(ostream& ss) const
      << std::endl;
 }
 
-void PGMap::get_stuck_stats(int types, utime_t cutoff,
+void PGMap::get_stuck_stats(int types, const utime_t cutoff,
                             ceph::unordered_map<pg_t, pg_stat_t>& stuck_pgs) const
 {
   assert(types != 0);
@@ -955,6 +955,54 @@ void PGMap::get_stuck_stats(int types, utime_t cutoff,
   }
 }
 
+bool PGMap::get_stuck_counts(const utime_t cutoff, map<string, int>& note) const
+{
+  int inactive = 0;
+  int unclean = 0;
+  int degraded = 0;
+  int undersized = 0;
+  int stale = 0;
+
+  for (ceph::unordered_map<pg_t, pg_stat_t>::const_iterator i = pg_stat.begin();
+       i != pg_stat.end();
+       ++i) {
+
+    if (! (i->second.state & PG_STATE_ACTIVE)) {
+      if (i->second.last_active < cutoff)
+        ++inactive;
+    } else if (! (i->second.state & PG_STATE_CLEAN)) {
+      if (i->second.last_clean < cutoff)
+        ++unclean;
+    } else if (i->second.state & PG_STATE_DEGRADED) {
+      if (i->second.last_undegraded < cutoff)
+        ++degraded;
+    } else if (i->second.state & PG_STATE_UNDERSIZED) {
+      if (i->second.last_fullsized < cutoff)
+        ++undersized;
+    } else if (i->second.state & PG_STATE_STALE) {
+      if (i->second.last_unstale < cutoff)
+        ++stale;
+    }
+  }
+
+  if (inactive)
+    note["stuck inactive"] = inactive;
+
+  if (unclean)
+    note["stuck unclean"] = unclean;
+
+  if (undersized)
+    note["stuck undersized"] = undersized;
+
+  if (degraded)
+    note["stuck degraded"] = degraded;
+
+  if (stale)
+    note["stuck stale"] = stale; 
+
+  return inactive || unclean || undersized || degraded || stale;
+}
+
 void PGMap::dump_stuck(Formatter *f, int types, utime_t cutoff) const
 {
   ceph::unordered_map<pg_t, pg_stat_t> stuck_pg_stats;

src/mon/PGMap.h

@@ -282,8 +282,9 @@ class PGMap {
   void dump_pg_stats_plain(ostream& ss,
 			   const ceph::unordered_map<pg_t, pg_stat_t>& pg_stats,
 			   bool brief) const;
-  void get_stuck_stats(int types, utime_t cutoff,
+  void get_stuck_stats(int types, const utime_t cutoff,
 		       ceph::unordered_map<pg_t, pg_stat_t>& stuck_pgs) const;
+  bool get_stuck_counts(const utime_t cutoff, map<string, int>& note) const;
   void dump_stuck(Formatter *f, int types, utime_t cutoff) const;
   void dump_stuck_plain(ostream& ss, int types, utime_t cutoff) const;
 

src/mon/PGMonitor.cc

@@ -2145,46 +2145,60 @@ void PGMonitor::get_health(list<pair<health_status_t,string> >& summary,
   utime_t now(ceph_clock_now(g_ceph_context));
   utime_t cutoff = now - utime_t(g_conf->mon_pg_stuck_threshold, 0);
   uint64_t num_inactive_pgs = 0;
+
+  if (detail) {
+
+    // we need to collect details of stuck pgs, first do a quick check
+    // whether this will yield any results
+    if (pg_map.get_stuck_counts(cutoff, note)) {
+
+      // there are stuck pgs. gather details for specified statuses
+      // only if we know that there are pgs stuck in that status
+
+      if (note.find("stuck inactive") != note.end()) {
+        pg_map.get_stuck_stats(PGMap::STUCK_INACTIVE, cutoff, stuck_pgs);
+        note["stuck inactive"] = stuck_pgs.size();
+        num_inactive_pgs += stuck_pgs.size();
+        note_stuck_detail(PGMap::STUCK_INACTIVE, stuck_pgs, detail);
+        stuck_pgs.clear();
+      }
 
-  pg_map.get_stuck_stats(PGMap::STUCK_INACTIVE, cutoff, stuck_pgs);
-  if (!stuck_pgs.empty()) {
-    note["stuck inactive"] = stuck_pgs.size();
-    num_inactive_pgs += stuck_pgs.size();
-    if (detail)
-      note_stuck_detail(PGMap::STUCK_INACTIVE, stuck_pgs, detail);
-  }
-  stuck_pgs.clear();
-
-  pg_map.get_stuck_stats(PGMap::STUCK_UNCLEAN, cutoff, stuck_pgs);
-  if (!stuck_pgs.empty()) {
-    note["stuck unclean"] = stuck_pgs.size();
-    if (detail)
-      note_stuck_detail(PGMap::STUCK_UNCLEAN, stuck_pgs, detail);
-  }
-  stuck_pgs.clear();
+      if (note.find("stuck unclean") != note.end()) {
+        pg_map.get_stuck_stats(PGMap::STUCK_UNCLEAN, cutoff, stuck_pgs);
+        note["stuck unclean"] = stuck_pgs.size();
+        note_stuck_detail(PGMap::STUCK_UNCLEAN, stuck_pgs, detail);
+        stuck_pgs.clear();
+      }
 
-  pg_map.get_stuck_stats(PGMap::STUCK_UNDERSIZED, cutoff, stuck_pgs);
-  if (!stuck_pgs.empty()) {
-    note["stuck undersized"] = stuck_pgs.size();
-    if (detail)
-      note_stuck_detail(PGMap::STUCK_UNDERSIZED, stuck_pgs, detail);
-  }
-  stuck_pgs.clear();
+      if (note.find("stuck undersized") != note.end()) {
+        pg_map.get_stuck_stats(PGMap::STUCK_UNDERSIZED, cutoff, stuck_pgs);
+        note["stuck undersized"] = stuck_pgs.size();
+        note_stuck_detail(PGMap::STUCK_UNDERSIZED, stuck_pgs, detail);
+        stuck_pgs.clear();
+      }
 
-  pg_map.get_stuck_stats(PGMap::STUCK_DEGRADED, cutoff, stuck_pgs);
-  if (!stuck_pgs.empty()) {
-    note["stuck degraded"] = stuck_pgs.size();
-    if (detail)
-      note_stuck_detail(PGMap::STUCK_DEGRADED, stuck_pgs, detail);
-  }
-  stuck_pgs.clear();
+      if (note.find("stuck degraded") != note.end()) {
+        pg_map.get_stuck_stats(PGMap::STUCK_DEGRADED, cutoff, stuck_pgs);
+        note["stuck degraded"] = stuck_pgs.size();
+        note_stuck_detail(PGMap::STUCK_DEGRADED, stuck_pgs, detail);
+        stuck_pgs.clear();
+      }
 
-  pg_map.get_stuck_stats(PGMap::STUCK_STALE, cutoff, stuck_pgs);
-  if (!stuck_pgs.empty()) {
-    note["stuck stale"] = stuck_pgs.size();
-    num_inactive_pgs += stuck_pgs.size();
-    if (detail)
-      note_stuck_detail(PGMap::STUCK_STALE, stuck_pgs, detail);
+      if (note.find("stuck stale") != note.end()) {
+        pg_map.get_stuck_stats(PGMap::STUCK_STALE, cutoff, stuck_pgs);
+        note["stuck stale"] = stuck_pgs.size();
+        num_inactive_pgs += stuck_pgs.size();
+        note_stuck_detail(PGMap::STUCK_STALE, stuck_pgs, detail);
+      }
+    }
+  } else {
+    pg_map.get_stuck_counts(cutoff, note);
+    map<string,int>::const_iterator p = note.find("stuck inactive");
+    if (p != note.end()) 
+      num_inactive_pgs += p->second;
+    p = note.find("stuck stale");
+    if (p != note.end()) 
+      num_inactive_pgs += p->second;
   }
 
   if (g_conf->mon_pg_min_inactive > 0 && num_inactive_pgs >= g_conf->mon_pg_min_inactive) {