SERVER-40382 Add a serverStatus metric to report plan cache memory consumption

1 files changed, 156 insertions, 0 deletions

diff --git a/src/mongo/db/exec/plan_stats.h b/src/mongo/db/exec/plan_stats.h
index 938a633e342..9ec4d0b69a5 100644
--- a/src/mongo/db/exec/plan_stats.h
+++ b/src/mongo/db/exec/plan_stats.h
@@ -37,6 +37,7 @@
 #include "mongo/db/index/multikey_paths.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/query/stage_types.h"
+#include "mongo/util/container_size_helper.h"
 #include "mongo/util/time_support.h"
 
 namespace mongo {
@@ -51,6 +52,8 @@ struct SpecificStats {
      * Make a deep copy.
      */
     virtual SpecificStats* clone() const = 0;
+
+    virtual uint64_t estimateObjectSizeInBytes() const = 0;
 };
 
 // Every stage has CommonStats.
@@ -66,6 +69,10 @@ struct CommonStats {
           executionTimeMillis(0),
           failed(false),
           isEOF(false) {}
+
+    uint64_t estimateObjectSizeInBytes() const {
+        return filter.objsize() + sizeof(*this);
+    }
     // String giving the type of the stage. Not owned.
     const char* stageTypeStr;
 
@@ -121,6 +128,20 @@ struct PlanStageStats {
         return stats;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return  // Add size of each element in 'children' vector.
+            container_size_helper::estimateObjectSizeInBytes(
+                children,
+                [](const auto& child) { return child->estimateObjectSizeInBytes(); },
+                true) +
+            // Exclude the size of 'common' object since is being added later.
+            (common.estimateObjectSizeInBytes() - sizeof(common)) +
+            // Add 'specific' object size if exists.
+            (specific ? specific->estimateObjectSizeInBytes() : 0) +
+            // Add size of the object.
+            sizeof(*this);
+    }
+
     // See query/stage_type.h
     StageType stageType;
 
@@ -146,6 +167,10 @@ struct AndHashStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return container_size_helper::estimateObjectSizeInBytes(mapAfterChild) + sizeof(*this);
+    }
+
     // How many entries are in the map after each child?
     // child 'i' produced children[i].common.advanced RecordIds, of which mapAfterChild[i] were
     // intersections.
@@ -169,6 +194,10 @@ struct AndSortedStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return container_size_helper::estimateObjectSizeInBytes(failedAnd) + sizeof(*this);
+    }
+
     // How many results from each child did not pass the AND?
     std::vector<size_t> failedAnd;
 };
@@ -180,6 +209,10 @@ struct CachedPlanStats : public SpecificStats {
         return new CachedPlanStats(*this);
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     bool replanned;
 };
 
@@ -191,6 +224,11 @@ struct CollectionScanStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
+
     // How many documents did we check against our filter?
     size_t docsTested;
 
@@ -217,6 +255,10 @@ struct CountStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     // The result of the count.
     long long nCounted;
 
@@ -243,6 +285,18 @@ struct CountScanStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return container_size_helper::estimateObjectSizeInBytes(
+                   multiKeyPaths,
+                   [](const auto& keyPath) {
+                       // Calculate the size of each std::set in 'multiKeyPaths'.
+                       return container_size_helper::estimateObjectSizeInBytes(keyPath);
+                   },
+                   true) +
+            keyPattern.objsize() + collation.objsize() + startKey.objsize() + endKey.objsize() +
+            indexName.capacity() + sizeof(*this);
+    }
+
     std::string indexName;
 
     BSONObj keyPattern;
@@ -280,6 +334,10 @@ struct DeleteStats : public SpecificStats {
         return new DeleteStats(*this);
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t docsDeleted = 0u;
 };
 
@@ -293,6 +351,18 @@ struct DistinctScanStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return container_size_helper::estimateObjectSizeInBytes(
+                   multiKeyPaths,
+                   [](const auto& keyPath) {
+                       // Calculate the size of each std::set in 'multiKeyPaths'.
+                       return container_size_helper::estimateObjectSizeInBytes(keyPath);
+                   },
+                   true) +
+            keyPattern.objsize() + collation.objsize() + indexBounds.objsize() +
+            indexName.capacity() + sizeof(*this);
+    }
+
     // How many keys did we look at while distinct-ing?
     size_t keysExamined = 0;
 
@@ -329,6 +399,10 @@ struct EnsureSortedStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     // The number of out-of-order results that were dropped.
     long long nDropped;
 };
@@ -341,6 +415,10 @@ struct FetchStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     // Have we seen anything that already had an object?
     size_t alreadyHasObj = 0u;
 
@@ -356,6 +434,10 @@ struct IDHackStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return indexName.capacity() + sizeof(*this);
+    }
+
     std::string indexName;
 
     // Number of entries retrieved from the index while executing the idhack.
@@ -387,6 +469,18 @@ struct IndexScanStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return container_size_helper::estimateObjectSizeInBytes(
+                   multiKeyPaths,
+                   [](const auto& keyPath) {
+                       // Calculate the size of each std::set in 'multiKeyPaths'.
+                       return container_size_helper::estimateObjectSizeInBytes(keyPath);
+                   },
+                   true) +
+            keyPattern.objsize() + collation.objsize() + indexBounds.objsize() +
+            indexName.capacity() + indexType.capacity() + sizeof(*this);
+    }
+
     // Index type being used.
     std::string indexType;
 
@@ -436,6 +530,10 @@ struct LimitStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t limit;
 };
 
@@ -445,6 +543,10 @@ struct MockStats : public SpecificStats {
     SpecificStats* clone() const final {
         return new MockStats(*this);
     }
+
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
 };
 
 struct MultiPlanStats : public SpecificStats {
@@ -453,6 +555,10 @@ struct MultiPlanStats : public SpecificStats {
     SpecificStats* clone() const final {
         return new MultiPlanStats(*this);
     }
+
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
 };
 
 struct OrStats : public SpecificStats {
@@ -463,6 +569,10 @@ struct OrStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t dupsTested = 0u;
     size_t dupsDropped = 0u;
 };
@@ -475,6 +585,10 @@ struct ProjectionStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return projObj.objsize() + sizeof(*this);
+    }
+
     // Object specifying the projection transformation to apply.
     BSONObj projObj;
 };
@@ -487,6 +601,10 @@ struct SortStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sortPattern.objsize() + sizeof(*this);
+    }
+
     // What's our current memory usage?
     size_t memUsage = 0u;
 
@@ -508,6 +626,10 @@ struct MergeSortStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sortPattern.objsize() + sizeof(*this);
+    }
+
     size_t dupsTested = 0u;
     size_t dupsDropped = 0u;
 
@@ -523,6 +645,10 @@ struct ShardingFilterStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t chunkSkips;
 };
 
@@ -534,6 +660,10 @@ struct SkipStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t skip;
 };
 
@@ -558,6 +688,11 @@ struct NearStats : public SpecificStats {
         return new NearStats(*this);
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return container_size_helper::estimateObjectSizeInBytes(intervalStats) +
+            keyPattern.objsize() + indexName.capacity() + sizeof(*this);
+    }
+
     std::vector<IntervalStats> intervalStats;
     std::string indexName;
     // btree index version, not geo index version
@@ -572,6 +707,10 @@ struct UpdateStats : public SpecificStats {
         return new UpdateStats(*this);
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return objInserted.objsize() + sizeof(*this);
+    }
+
     // The number of documents which match the query part of the update.
     size_t nMatched;
 
@@ -596,6 +735,11 @@ struct TextStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return parsedTextQuery.objsize() + indexPrefix.objsize() + indexName.capacity() +
+            sizeof(*this);
+    }
+
     std::string indexName;
 
     // Human-readable form of the FTSQuery associated with the text stage.
@@ -615,6 +759,10 @@ struct TextMatchStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t docsRejected;
 };
 
@@ -626,6 +774,10 @@ struct TextOrStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t fetches;
 };
 
@@ -635,6 +787,10 @@ struct TrialStats : public SpecificStats {
         return specific;
     }
 
+    uint64_t estimateObjectSizeInBytes() const {
+        return sizeof(*this);
+    }
+
     size_t trialPeriodMaxWorks = 0;
     double successThreshold = 0;