SERVER-63642 Add serverStatus histogram metrics to measure multi-planning performance

1 files changed, 104 insertions, 0 deletions

diff --git a/jstests/noPassthrough/server_status_multiplanner.js b/jstests/noPassthrough/server_status_multiplanner.js
new file mode 100644
index 00000000000..f185cdb7841
--- /dev/null
+++ b/jstests/noPassthrough/server_status_multiplanner.js
@@ -0,0 +1,104 @@
+/**
+ * Tests the serverStatus and FTDC metrics for multi planner execution (both classic and SBE).
+ */
+(function() {
+"use strict";
+
+function sumHistogramBucketCounts(histogram) {
+    let sum = 0;
+    for (const bucket of histogram) {
+        sum += bucket.count;
+    }
+    return sum;
+}
+
+load("jstests/libs/ftdc.js");
+
+const collName = jsTestName();
+const dbName = jsTestName();
+
+// Use an isolated server instance to obtain predictible serverStatus planning metrics.
+const conn = MongoRunner.runMongod({});
+assert.neq(conn, null, "mongod failed to start");
+const db = conn.getDB(dbName);
+
+let coll = db.getCollection(collName);
+coll.drop();
+
+assert.commandWorked(coll.insert({_id: 3, a: 1, b: 1}));
+assert.commandWorked(coll.insert({_id: 5, a: 1, b: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
+assert.commandWorked(coll.createIndex({b: 1}));
+
+let multiPlannerMetrics = db.serverStatus().metrics.query.multiPlanner;
+
+// Verify initial metrics.
+assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.classicMicros), 0);
+assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.classicNumPlans), 0);
+assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.classicWorks), 0);
+assert.eq(multiPlannerMetrics.classicCount, 0);
+assert.eq(multiPlannerMetrics.classicMicros, 0);
+assert.eq(multiPlannerMetrics.classicWorks, 0);
+
+assert.eq(multiPlannerMetrics.histograms.classicMicros[0].lowerBound, 0);
+
+// Run with classic engine and verify metrics.
+{
+    assert.commandWorked(db.adminCommand({setParameter: 1, internalQueryForceClassicEngine: true}));
+    assert.commandWorked(coll.find({a: 1, b: 1, c: 1}).explain());
+
+    multiPlannerMetrics = db.serverStatus().metrics.query.multiPlanner;
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.sbeMicros), 0);
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.sbeNumReads), 0);
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.sbeNumPlans), 0);
+    assert.eq(multiPlannerMetrics.sbeMicros, 0);
+    assert.eq(multiPlannerMetrics.sbeNumReads, 0);
+    assert.eq(multiPlannerMetrics.sbeCount, 0);
+
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.classicMicros), 1);
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.classicNumPlans), 1);
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.classicWorks), 1);
+    assert.eq(multiPlannerMetrics.classicCount, 1);
+    assert.gt(multiPlannerMetrics.classicMicros, 0);
+    assert.gt(multiPlannerMetrics.classicWorks, 0);
+}
+
+// Run with SBE and verify metrics.
+{
+    assert.commandWorked(
+        db.adminCommand({setParameter: 1, internalQueryForceClassicEngine: false}));
+    assert.commandWorked(coll.find({a: 1, b: 1, c: 1}).explain());
+
+    multiPlannerMetrics = db.serverStatus().metrics.query.multiPlanner;
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.sbeMicros), 1);
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.sbeNumReads), 1);
+    assert.eq(sumHistogramBucketCounts(multiPlannerMetrics.histograms.sbeNumPlans), 1);
+    assert.gt(multiPlannerMetrics.sbeMicros, 0);
+    assert.gt(multiPlannerMetrics.sbeNumReads, 0);
+    assert.eq(multiPlannerMetrics.sbeCount, 1);
+
+    // Sanity check.
+    assert.eq(multiPlannerMetrics.classicCount, 1);
+}
+
+assert.soon(() => {
+    // Verify FTDC includes aggregate metrics.
+    const multiPlannerMetricsFtdc =
+        verifyGetDiagnosticData(conn.getDB("admin")).serverStatus.metrics.query.multiPlanner;
+    if (multiPlannerMetricsFtdc.classicCount == 0 || multiPlannerMetricsFtdc.sbeCount == 0) {
+        // This is an indication we haven't retrieve the expected serverStatus metrics yet.
+        return false;
+    }
+    assert.eq(multiPlannerMetricsFtdc.classicCount, 1);
+    assert.gt(multiPlannerMetricsFtdc.classicMicros, 0);
+    assert.gt(multiPlannerMetricsFtdc.classicWorks, 0);
+    assert.eq(multiPlannerMetricsFtdc.sbeCount, 1);
+    assert.gt(multiPlannerMetricsFtdc.sbeMicros, 0);
+    assert.gt(multiPlannerMetricsFtdc.sbeNumReads, 0);
+    // Verify FTDC omits detailed histograms.
+    assert(!multiPlannerMetricsFtdc.hasOwnProperty("histograms"));
+    return true;
+}, "FTDC output should eventually reflect observed serverStatus metrics.");
+
+MongoRunner.stopMongod(conn);
+}());