SERVER-47641 Report total number of range deletion tasks in serverStatus rather than per collection

(cherry picked from commit fa945325938ada67a088e7dbe951404d092e8771)
(cherry picked from commit 9717e231da81bddfeef636fd99b93725a2c2a1c2)

9 files changed, 42 insertions, 44 deletions

diff --git a/jstests/sharding/range_deleter_server_status.js b/jstests/sharding/range_deleter_server_status.js
index c9f49bfdf32..47eb893794c 100644
--- a/jstests/sharding/range_deleter_server_status.js
+++ b/jstests/sharding/range_deleter_server_status.js
@@ -48,11 +48,7 @@ assert.commandWorked(
 
 let shardDB = st.rs0.getPrimary().getDB('test');
 let serverStatusRes = shardDB.runCommand({serverStatus: 1});
-
-let expectedList = [{'test.foo': 2}, {'test.bar': 1}];
-let taskList = serverStatusRes.shardingStatistics.rangeDeleterTasks;
-assert.eq(2, taskList.length, tojson(taskList));
-assert.sameMembers(expectedList, taskList);
+assert.eq(3, serverStatusRes.shardingStatistics.rangeDeleterTasks);
 
 // Close the cursors so the range deleter tasks can proceed and so there won't be tasks that
 // can't make progress when the check orphan hooks runs.
diff --git a/src/mongo/db/s/collection_sharding_runtime.cpp b/src/mongo/db/s/collection_sharding_runtime.cpp
index 0130c1d2f23..f233adf743a 100644
--- a/src/mongo/db/s/collection_sharding_runtime.cpp
+++ b/src/mongo/db/s/collection_sharding_runtime.cpp
@@ -404,19 +404,20 @@ CollectionShardingRuntime::_getMetadataWithVersionCheckAt(
     MONGO_UNREACHABLE;
 }
 
-void CollectionShardingRuntime::appendInfoForServerStatus(BSONArrayBuilder* builder) {
-    stdx::lock_guard lk(_metadataManagerLock);
-    if (_metadataManager) {
-        _metadataManager->appendForServerStatus(builder);
-    }
-}
-
 void CollectionShardingRuntime::clearReceivingChunks() {
     stdx::lock_guard lk(_metadataManagerLock);
     invariant(_metadataType == MetadataType::kSharded);
     _metadataManager->clearReceivingChunks();
 }
 
+size_t CollectionShardingRuntime::numberOfRangesScheduledForDeletion() const {
+    stdx::lock_guard lk(_metadataManagerLock);
+    if (_metadataManager) {
+        return _metadataManager->numberOfRangesScheduledForDeletion();
+    }
+    return 0;
+}
+
 CollectionCriticalSection::CollectionCriticalSection(OperationContext* opCtx, NamespaceString ns)
     : _nss(std::move(ns)), _opCtx(opCtx) {
     AutoGetCollection autoColl(_opCtx,
diff --git a/src/mongo/db/s/collection_sharding_runtime.h b/src/mongo/db/s/collection_sharding_runtime.h
index 009e012441f..3d22f8e8240 100644
--- a/src/mongo/db/s/collection_sharding_runtime.h
+++ b/src/mongo/db/s/collection_sharding_runtime.h
@@ -105,7 +105,7 @@ public:
 
     void setFilteringMetadata(OperationContext* opCtx, CollectionMetadata newMetadata) override;
 
-    void appendInfoForServerStatus(BSONArrayBuilder* builder) override;
+    size_t numberOfRangesScheduledForDeletion() const override;
 
     /**
      * Marks the collection's filtering metadata as UNKNOWN, meaning that all attempts to check for
diff --git a/src/mongo/db/s/collection_sharding_state.cpp b/src/mongo/db/s/collection_sharding_state.cpp
index c50c00a9a06..1e7c2e06056 100644
--- a/src/mongo/db/s/collection_sharding_state.cpp
+++ b/src/mongo/db/s/collection_sharding_state.cpp
@@ -92,16 +92,18 @@ public:
     }
 
     void appendInfoForServerStatus(BSONObjBuilder* builder) {
-        BSONArrayBuilder rangeDeleterArrayBuilder(builder->subarrayStart("rangeDeleterTasks"));
-
-        {
+        auto totalNumberOfRangesScheduledForDeletion = ([this] {
             stdx::lock_guard lg(_mutex);
-            for (auto& coll : _collections) {
-                coll.second->appendInfoForServerStatus(&rangeDeleterArrayBuilder);
-            }
-        }
-
-        rangeDeleterArrayBuilder.done();
+            return std::accumulate(_collections.begin(),
+                                   _collections.end(),
+                                   0LL,
+                                   [](long long total, const auto& coll) {
+                                       return total +
+                                           coll.second->numberOfRangesScheduledForDeletion();
+                                   });
+        })();
+
+        builder->appendNumber("rangeDeleterTasks", totalNumberOfRangesScheduledForDeletion);
     }
 
 private:
diff --git a/src/mongo/db/s/collection_sharding_state.h b/src/mongo/db/s/collection_sharding_state.h
index 2b46af3274c..6885b1d0c7e 100644
--- a/src/mongo/db/s/collection_sharding_state.h
+++ b/src/mongo/db/s/collection_sharding_state.h
@@ -182,9 +182,9 @@ public:
     virtual void setFilteringMetadata(OperationContext* opCtx, CollectionMetadata newMetadata) = 0;
 
     /**
-     * Append info to display in server status.
+     * Returns the number of ranges scheduled for deletion on the collection.
      */
-    virtual void appendInfoForServerStatus(BSONArrayBuilder* builder) = 0;
+    virtual size_t numberOfRangesScheduledForDeletion() const = 0;
 };
 
 /**
diff --git a/src/mongo/db/s/collection_sharding_state_factory_embedded.cpp b/src/mongo/db/s/collection_sharding_state_factory_embedded.cpp
index c46090d2034..bf00246ab6f 100644
--- a/src/mongo/db/s/collection_sharding_state_factory_embedded.cpp
+++ b/src/mongo/db/s/collection_sharding_state_factory_embedded.cpp
@@ -83,9 +83,12 @@ public:
     }
 
     void toBSONPending(BSONArrayBuilder&) const override {}
-    void appendInfoForServerStatus(BSONArrayBuilder* builder) {}
 
     void setFilteringMetadata(OperationContext*, CollectionMetadata) override {}
+
+    size_t numberOfRangesScheduledForDeletion() const override {
+        return 0;
+    }
 };
 
 class CollectionShardingStateFactoryEmbedded final : public CollectionShardingStateFactory {
diff --git a/src/mongo/db/s/collection_sharding_state_factory_standalone.cpp b/src/mongo/db/s/collection_sharding_state_factory_standalone.cpp
index c2ca5dd0c47..a405f728c68 100644
--- a/src/mongo/db/s/collection_sharding_state_factory_standalone.cpp
+++ b/src/mongo/db/s/collection_sharding_state_factory_standalone.cpp
@@ -76,9 +76,12 @@ public:
     }
 
     void toBSONPending(BSONArrayBuilder& bb) const noexcept override {}
-    void appendInfoForServerStatus(BSONArrayBuilder* builder) override {}
 
     void setFilteringMetadata(OperationContext*, CollectionMetadata) noexcept override {}
+
+    size_t numberOfRangesScheduledForDeletion() const override {
+        return 0;
+    }
 };
 
 }  // namespace
diff --git a/src/mongo/db/s/metadata_manager.cpp b/src/mongo/db/s/metadata_manager.cpp
index 84bf965a0b9..92921daa893 100644
--- a/src/mongo/db/s/metadata_manager.cpp
+++ b/src/mongo/db/s/metadata_manager.cpp
@@ -342,19 +342,6 @@ void MetadataManager::append(BSONObjBuilder* builder) const {
     amrArr.done();
 }
 
-void MetadataManager::appendForServerStatus(BSONArrayBuilder* builder) const {
-    auto numRangeDeletes = ([this] {
-        stdx::lock_guard<Latch> lg(_managerLock);
-        return _rangesScheduledForDeletion.size();
-    })();
-
-    if (numRangeDeletes > 0) {
-        BSONObjBuilder statBuilder;
-        statBuilder.appendNumber(_nss.ns(), numRangeDeletes);
-        builder->append(statBuilder.obj());
-    }
-}
-
 SharedSemiFuture<void> MetadataManager::beginReceive(ChunkRange const& range) {
     stdx::lock_guard<Latch> lg(_managerLock);
     invariant(!_metadata.empty());
@@ -481,6 +468,11 @@ size_t MetadataManager::numberOfRangesToClean() const {
     return _rangesScheduledForDeletion.size() - rangesToCleanInUse;
 }
 
+size_t MetadataManager::numberOfRangesScheduledForDeletion() const {
+    stdx::lock_guard<Latch> lg(_managerLock);
+    return _rangesScheduledForDeletion.size();
+}
+
 boost::optional<SharedSemiFuture<void>> MetadataManager::trackOrphanedDataCleanup(
     ChunkRange const& range) const {
     stdx::lock_guard<Latch> lg(_managerLock);
diff --git a/src/mongo/db/s/metadata_manager.h b/src/mongo/db/s/metadata_manager.h
index 832fb7aade7..20f126eabbf 100644
--- a/src/mongo/db/s/metadata_manager.h
+++ b/src/mongo/db/s/metadata_manager.h
@@ -124,11 +124,6 @@ public:
     void append(BSONObjBuilder* builder) const;
 
     /**
-     * Appends summarized information for server status.
-     */
-    void appendForServerStatus(BSONArrayBuilder* builder) const;
-
-    /**
      * Schedules any documents in `range` for immediate cleanup iff no running queries can depend
      * on them, and adds the range to the list of ranges currently being received.
      *
@@ -171,6 +166,12 @@ public:
     size_t numberOfRangesToCleanStillInUse() const;
 
     /**
+     * Returns the number of ranges scheduled for deletion, regardless of whether they may still be
+     * in use by running queries.
+     */
+    size_t numberOfRangesScheduledForDeletion() const;
+
+    /**
      * Reports whether any range still scheduled for deletion overlaps the argument range. If so,
      * returns a future that will be resolved when the newest overlapping range's deletion (possibly
      * the one of interest) completes or fails.