SERVER-22048 Record index access stats for aggregation and mapReduce

3 files changed, 32 insertions, 0 deletions

diff --git a/jstests/core/index_stats.js b/jstests/core/index_stats.js
index 5ef871bf2da..acf2951213b 100644
--- a/jstests/core/index_stats.js
+++ b/jstests/core/index_stats.js
@@ -88,6 +88,23 @@
     countB++;
     assert.eq(countB, getUsageCount("b_1_c_1"));
 
+    // Confirm index stats tick on aggregate w/ match.
+    res = db.runCommand({aggregate: colName,
+                         pipeline: [{$match: {b: 1}}]});
+    assert.commandWorked(res);
+    countB++;
+    assert.eq(countB, getUsageCount("b_1_c_1"));
+
+    // Confirm index stats tick on mapReduce with query.
+    res = db.runCommand({mapReduce: colName,
+                         map: function() {emit(this.b, this.c);},
+                         reduce: function(key, val) {return val;},
+                         query: {b: 2},
+                         out: {inline: true}});
+    assert.commandWorked(res);
+    countB++;
+    assert.eq(countB, getUsageCount("b_1_c_1"));
+
     // Confirm index stats tick on update().
     assert.writeOK(col.update({a: 2}, {$set: {d: 2}}));
     countA++;
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index d0066e7e066..27edf464286 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -1465,6 +1465,11 @@ public:
                     if (config.limit && numInputs >= config.limit)
                         break;
                 }
+
+                // Record the indexes used by the PlanExecutor.
+                PlanSummaryStats stats;
+                Explain::getSummaryStats(*exec, &stats);
+                coll->infoCache()->notifyOfQuery(txn, stats.indexesUsed);
             }
             pm.finished();
 
diff --git a/src/mongo/db/commands/pipeline_command.cpp b/src/mongo/db/commands/pipeline_command.cpp
index ada7e33e311..f8bbf2fc81c 100644
--- a/src/mongo/db/commands/pipeline_command.cpp
+++ b/src/mongo/db/commands/pipeline_command.cpp
@@ -228,6 +228,16 @@ public:
                 PipelineD::prepareCursorSource(txn, collection, pPipeline, pCtx);
             pPipeline->stitch();
 
+            if (collection && input) {
+                // Record the indexes used by the input executor. Retrieval of summary stats for a
+                // PlanExecutor is normally done post execution. DocumentSourceCursor however will
+                // destroy the input PlanExecutor once the result set has been exhausted. For
+                // that reason we need to collect the indexes used prior to plan execution.
+                PlanSummaryStats stats;
+                Explain::getSummaryStats(*input, &stats);
+                collection->infoCache()->notifyOfQuery(txn, stats.indexesUsed);
+            }
+
             // Create the PlanExecutor which returns results from the pipeline. The WorkingSet
             // ('ws') and the PipelineProxyStage ('proxy') will be owned by the created
             // PlanExecutor.