SERVER-50286 Indicate in logs whether an operation involves a view

3 files changed, 90 insertions, 0 deletions

diff --git a/src/mongo/db/curop.cpp b/src/mongo/db/curop.cpp
index 32dd1a531d4..20bc4610e65 100644
--- a/src/mongo/db/curop.cpp
+++ b/src/mongo/db/curop.cpp
@@ -882,6 +882,10 @@ string OpDebug::report(OperationContext* opCtx, const SingleThreadedLockStats* l
         s << " dataThroughputAverage: " << *dataThroughputAverage << " MB/sec";
     }
 
+    if (!resolvedViews.empty()) {
+        s << " resolvedViews: " << getResolvedViewsInfo();
+    }
+
     OPDEBUG_TOSTRING_HELP(nShards);
     OPDEBUG_TOSTRING_HELP(cursorid);
     if (mongotCursorId) {
@@ -1061,6 +1065,10 @@ void OpDebug::report(OperationContext* opCtx,
         pAttrs->add("dataThroughputAverageMBPerSec", *dataThroughputAverage);
     }
 
+    if (!resolvedViews.empty()) {
+        pAttrs->add("resolvedViews", getResolvedViewsInfo());
+    }
+
     OPDEBUG_TOATTR_HELP(nShards);
     OPDEBUG_TOATTR_HELP(cursorid);
     if (mongotCursorId) {
@@ -1205,6 +1213,10 @@ void OpDebug::append(OperationContext* opCtx,
         appendAsObjOrString("originatingCommand", originatingCommand, appendMaxElementSize, &b);
     }
 
+    if (!resolvedViews.empty()) {
+        appendResolvedViewsInfo(b);
+    }
+
     OPDEBUG_APPEND_NUMBER(b, nShards);
     OPDEBUG_APPEND_NUMBER(b, cursorid);
     if (mongotCursorId) {
@@ -1667,6 +1679,55 @@ BSONObj OpDebug::makeMongotDebugStatsObject() const {
     return cursorBuilder.obj();
 }
 
+void OpDebug::addResolvedViews(const std::vector<NamespaceString>& namespaces,
+                               const std::vector<BSONObj>& pipeline) {
+    if (namespaces.empty())
+        return;
+
+    if (resolvedViews.find(namespaces.front()) == resolvedViews.end()) {
+        resolvedViews[namespaces.front()] = std::make_pair(namespaces, pipeline);
+    }
+}
+
+static void appendResolvedViewsInfoImpl(
+    BSONArrayBuilder& resolvedViewsArr,
+    const std::map<NamespaceString, std::pair<std::vector<NamespaceString>, std::vector<BSONObj>>>&
+        resolvedViews) {
+    for (const auto& kv : resolvedViews) {
+        const NamespaceString& viewNss = kv.first;
+        const std::vector<NamespaceString>& dependencies = kv.second.first;
+        const std::vector<BSONObj>& pipeline = kv.second.second;
+
+        BSONObjBuilder aView;
+        aView.append("viewNamespace", viewNss.ns());
+
+        BSONArrayBuilder dependenciesArr(aView.subarrayStart("dependencyChain"));
+        for (const auto& nss : dependencies) {
+            dependenciesArr.append(nss.coll().toString());
+        }
+        dependenciesArr.doneFast();
+
+        BSONArrayBuilder pipelineArr(aView.subarrayStart("resolvedPipeline"));
+        for (const auto& stage : pipeline) {
+            pipelineArr.append(stage);
+        }
+        pipelineArr.doneFast();
+
+        resolvedViewsArr.append(redact(aView.done()));
+    }
+}
+
+BSONArray OpDebug::getResolvedViewsInfo() const {
+    BSONArrayBuilder resolvedViewsArr;
+    appendResolvedViewsInfoImpl(resolvedViewsArr, this->resolvedViews);
+    return resolvedViewsArr.arr();
+}
+
+void OpDebug::appendResolvedViewsInfo(BSONObjBuilder& builder) const {
+    BSONArrayBuilder resolvedViewsArr(builder.subarrayStart("resolvedViews"));
+    appendResolvedViewsInfoImpl(resolvedViewsArr, this->resolvedViews);
+    resolvedViewsArr.doneFast();
+}
 
 namespace {
 
diff --git a/src/mongo/db/curop.h b/src/mongo/db/curop.h
index 44530fcfbfd..aab0d9fad30 100644
--- a/src/mongo/db/curop.h
+++ b/src/mongo/db/curop.h
@@ -201,6 +201,18 @@ public:
      */
     BSONObj makeMongotDebugStatsObject() const;
 
+    /**
+     * Accumulate resolved views.
+     */
+    void addResolvedViews(const std::vector<NamespaceString>& namespaces,
+                          const std::vector<BSONObj>& pipeline);
+
+    /**
+     * Get or append the array with resolved views' info.
+     */
+    BSONArray getResolvedViewsInfo() const;
+    void appendResolvedViewsInfo(BSONObjBuilder& builder) const;
+
     // -------------------
 
     // basic options
@@ -279,6 +291,12 @@ public:
 
     // Whether this is an oplog getMore operation for replication oplog fetching.
     bool isReplOplogGetMore{false};
+
+    // Maps namespace of a resolved view to its dependency chain and the fully unrolled pipeline. To
+    // make log line deterministic and easier to test, use ordered map. As we don't expect many
+    // resolved views per query, a hash map would unlikely provide any benefits.
+    std::map<NamespaceString, std::pair<std::vector<NamespaceString>, std::vector<BSONObj>>>
+        resolvedViews;
 };
 
 /**
diff --git a/src/mongo/db/views/view_catalog.cpp b/src/mongo/db/views/view_catalog.cpp
index de708b34df2..d74e9148350 100644
--- a/src/mongo/db/views/view_catalog.cpp
+++ b/src/mongo/db/views/view_catalog.cpp
@@ -43,6 +43,7 @@
 #include "mongo/db/audit.h"
 #include "mongo/db/catalog/collection_catalog.h"
 #include "mongo/db/catalog/database.h"
+#include "mongo/db/curop.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/operation_context.h"
 #include "mongo/db/pipeline/aggregate_command_gen.h"
@@ -695,6 +696,8 @@ StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
         // 'resolvedNss'.
         std::shared_ptr<ViewDefinition> lastViewDefinition;
 
+        std::vector<NamespaceString> dependencyChain{nss};
+
         int depth = 0;
         for (; depth < ViewGraph::kMaxViewDepth; depth++) {
             auto view =
@@ -710,6 +713,10 @@ StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
                             str::stream() << "View pipeline exceeds maximum size; maximum size is "
                                           << ViewGraph::kMaxViewPipelineSizeBytes};
                 }
+
+                auto curOp = CurOp::get(opCtx);
+                curOp->debug().addResolvedViews(dependencyChain, resolvedPipeline);
+
                 return StatusWith<ResolvedView>(
                     {*resolvedNss,
                      std::move(resolvedPipeline),
@@ -717,6 +724,7 @@ StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
             }
 
             resolvedNss = &view->viewOn();
+            dependencyChain.push_back(*resolvedNss);
             if (!collation) {
                 collation = view->defaultCollator() ? view->defaultCollator()->getSpec().toBSON()
                                                     : CollationSpec::kSimpleSpec;
@@ -728,6 +736,9 @@ StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
 
             // If the first stage is a $collStats, then we return early with the viewOn namespace.
             if (toPrepend.size() > 0 && !toPrepend[0]["$collStats"].eoo()) {
+                auto curOp = CurOp::get(opCtx);
+                curOp->debug().addResolvedViews(dependencyChain, resolvedPipeline);
+
                 return StatusWith<ResolvedView>(
                     {*resolvedNss, std::move(resolvedPipeline), std::move(collation.get())});
             }