SERVER-69056 Show resource consumption metrics in explain

2 files changed, 89 insertions, 1 deletions

diff --git a/jstests/noPassthrough/explain_operation_metrics.js b/jstests/noPassthrough/explain_operation_metrics.js
new file mode 100644
index 00000000000..a50ae0c69c6
--- /dev/null
+++ b/jstests/noPassthrough/explain_operation_metrics.js
@@ -0,0 +1,75 @@
+/**
+ * Tests explain when profileOperationResourceConsumptionMetrics is set to true and explain
+ * verbosity is "executionStats" or "allPlansExecution".
+ * @tags: [
+ *   requires_replication,
+ *   requires_sharding,
+ *   requires_wiredtiger
+ * ]
+ */
+(function() {
+"use strict";
+const dbName = jsTestName();
+const collName = 'coll';
+
+const runTest = (db) => {
+    for (const verbosity of ["executionStats", "allPlansExecution"]) {
+        jsTestLog("Testing with verbosity: " + verbosity);
+        const coll = db[collName];
+        coll.drop();
+        const docs = [{a: 0, b: 0}, {a: 0, b: 0}, {a: 0, b: 0}];
+        assert.commandWorked(coll.insertMany(docs));
+
+        const result = assert.commandWorked(coll.find().explain(verbosity));
+        assert(result.hasOwnProperty("executionStats"), result);
+        const execStats = result.executionStats;
+        assert(execStats.hasOwnProperty("operationMetrics"), execStats);
+        const operationMetrics = execStats.operationMetrics;
+        assert.eq(132, operationMetrics.docBytesRead);
+        assert.eq(3, operationMetrics.docUnitsRead);
+
+        const aggResult =
+            assert.commandWorked(coll.explain(verbosity).aggregate({$project: {a: "$a"}}));
+        assert(aggResult.hasOwnProperty("executionStats"), aggResult);
+        const aggExecStats = aggResult.executionStats;
+        assert(aggExecStats.hasOwnProperty("operationMetrics"), aggExecStats);
+        const aggOperationMetrics = aggExecStats.operationMetrics;
+        assert.eq(132, aggOperationMetrics.docBytesRead);
+        assert.eq(3, aggOperationMetrics.docUnitsRead);
+
+        assert.commandWorked(coll.createIndex({a: 1}));
+        const idxFindResult = assert.commandWorked(coll.find({a: 0}).explain(verbosity));
+        assert(idxFindResult.hasOwnProperty("executionStats"), idxFindResult);
+        const idxFindExecutionStats = idxFindResult.executionStats;
+        assert(idxFindExecutionStats.hasOwnProperty("operationMetrics"), idxFindExecutionStats);
+        const idxFindOperationMetrics = idxFindExecutionStats.operationMetrics;
+        assert.eq(132, idxFindOperationMetrics.docBytesRead);
+        assert.eq(3, idxFindOperationMetrics.docUnitsRead);
+        assert.eq(12, idxFindOperationMetrics.idxEntryBytesRead);
+        assert.eq(3, idxFindOperationMetrics.idxEntryUnitsRead);
+        assert.eq(4, idxFindOperationMetrics.cursorSeeks);
+    }
+};
+
+const setParams = {
+    profileOperationResourceConsumptionMetrics: true
+};
+
+jsTestLog("Testing standalone");
+(function testStandalone() {
+    const conn = MongoRunner.runMongod({setParameter: setParams});
+    const db = conn.getDB(dbName);
+    runTest(db);
+    MongoRunner.stopMongod(conn);
+})();
+
+jsTestLog("Testing replica set");
+(function testReplicaSet() {
+    const rst = new ReplSetTest({nodes: 2, nodeOptions: {setParameter: setParams}});
+    rst.startSet();
+    rst.initiate();
+    const db = rst.getPrimary().getDB(dbName);
+    runTest(db);
+    rst.stopSet();
+})();
+})();
diff --git a/src/mongo/db/query/explain.cpp b/src/mongo/db/query/explain.cpp
index 3c9cbe69c1d..9a460447ba8 100644
--- a/src/mongo/db/query/explain.cpp
+++ b/src/mongo/db/query/explain.cpp
@@ -59,6 +59,7 @@
 #include "mongo/db/query/query_settings_decoration.h"
 #include "mongo/db/query/stage_builder.h"
 #include "mongo/db/server_options.h"
+#include "mongo/db/stats/resource_consumption_metrics.h"
 #include "mongo/util/hex.h"
 #include "mongo/util/net/socket_utils.h"
 #include "mongo/util/overloaded_visitor.h"
@@ -222,6 +223,18 @@ void generateSinglePlanExecutionInfo(const PlanExplainer::PlanStatsDetails& deta
     out->append("executionStages", stats);
 }
 
+void generateOperationMetrics(PlanExecutor* exec, BSONObjBuilder* out) {
+    if (ResourceConsumption::isMetricsProfilingEnabled()) {
+        auto& metricsCollector = ResourceConsumption::MetricsCollector::get(exec->getOpCtx());
+        if (metricsCollector.hasCollectedMetrics()) {
+            BSONObjBuilder metricsBuilder(out->subobjStart("operationMetrics"));
+            auto& metrics = metricsCollector.getMetrics();
+            metrics.toBsonNonZeroFields(&metricsBuilder);
+            metricsBuilder.doneFast();
+        }
+    }
+}
+
 /**
  * Adds the "executionStats" field to out. Assumes that the PlanExecutor has already been executed
  * to the point of reaching EOF. Also assumes that verbosity >= kExecStats.
@@ -287,7 +300,7 @@ void generateExecutionInfo(PlanExecutor* exec,
         }
         allPlansBob.doneFast();
     }
-
+    generateOperationMetrics(exec, &execBob);
     execBob.doneFast();
 }