SERVER-26515 Create collection with v=2 index should include full index spec in oplog

8 files changed, 48 insertions, 21 deletions

diff --git a/src/mongo/db/catalog/collection.cpp b/src/mongo/db/catalog/collection.cpp
index 0df69a9d2e6..cccaa6b257b 100644
--- a/src/mongo/db/catalog/collection.cpp
+++ b/src/mongo/db/catalog/collection.cpp
@@ -918,7 +918,7 @@ Status Collection::truncate(OperationContext* txn) {
 
     // 4) re-create indexes
     for (size_t i = 0; i < indexSpecs.size(); i++) {
-        status = _indexCatalog.createIndexOnEmptyCollection(txn, indexSpecs[i]);
+        status = _indexCatalog.createIndexOnEmptyCollection(txn, indexSpecs[i]).getStatus();
         if (!status.isOK())
             return status;
     }
diff --git a/src/mongo/db/catalog/database.cpp b/src/mongo/db/catalog/database.cpp
index b667e5022a3..438c8ed91fe 100644
--- a/src/mongo/db/catalog/database.cpp
+++ b/src/mongo/db/catalog/database.cpp
@@ -579,22 +579,16 @@ Collection* Database::createCollection(OperationContext* txn,
     invariant(collection);
     _collections[ns] = collection;
 
+    BSONObj fullIdIndexSpec;
+
     if (createIdIndex) {
         if (collection->requiresIdIndex()) {
             if (options.autoIndexId == CollectionOptions::YES ||
                 options.autoIndexId == CollectionOptions::DEFAULT) {
-                // The creation of the _id index isn't replicated and is instead implicit in the
-                // creation of the collection. This means that the version of the _id index to build
-                // is technically unspecified. However, we're able to use the
-                // featureCompatibilityVersion of this server to determine the default index version
-                // to use because we apply commands (opType == 'c') in their own batch. This
-                // guarantees the write to the admin.system.version collection from the
-                // "setFeatureCompatibilityVersion" command either happens entirely before the
-                // collection creation or it happens entirely after.
                 const auto featureCompatibilityVersion =
                     serverGlobalParams.featureCompatibility.version.load();
                 IndexCatalog* ic = collection->getIndexCatalog();
-                uassertStatusOK(ic->createIndexOnEmptyCollection(
+                fullIdIndexSpec = uassertStatusOK(ic->createIndexOnEmptyCollection(
                     txn,
                     !idIndex.isEmpty() ? idIndex
                                        : ic->getDefaultIdIndexSpec(featureCompatibilityVersion)));
@@ -608,7 +602,7 @@ Collection* Database::createCollection(OperationContext* txn,
 
     auto opObserver = getGlobalServiceContext()->getOpObserver();
     if (opObserver)
-        opObserver->onCreateCollection(txn, nss, options);
+        opObserver->onCreateCollection(txn, nss, options, fullIdIndexSpec);
 
     return collection;
 }
diff --git a/src/mongo/db/catalog/index_catalog.cpp b/src/mongo/db/catalog/index_catalog.cpp
index e680a852360..f8d3a04f4c1 100644
--- a/src/mongo/db/catalog/index_catalog.cpp
+++ b/src/mongo/db/catalog/index_catalog.cpp
@@ -299,7 +299,8 @@ StatusWith<BSONObj> IndexCatalog::prepareSpecForCreate(OperationContext* txn,
     return fixed;
 }
 
-Status IndexCatalog::createIndexOnEmptyCollection(OperationContext* txn, BSONObj spec) {
+StatusWith<BSONObj> IndexCatalog::createIndexOnEmptyCollection(OperationContext* txn,
+                                                               BSONObj spec) {
     invariant(txn->lockState()->isCollectionLockedForMode(_collection->ns().toString(), MODE_X));
     invariant(_collection->numRecords(txn) == 0);
 
@@ -342,7 +343,7 @@ Status IndexCatalog::createIndexOnEmptyCollection(OperationContext* txn, BSONObj
     // sanity check
     invariant(_collection->getCatalogEntry()->isIndexReady(txn, descriptor->indexName()));
 
-    return Status::OK();
+    return spec;
 }
 
 IndexCatalog::IndexBuildBlock::IndexBuildBlock(OperationContext* txn,
diff --git a/src/mongo/db/catalog/index_catalog.h b/src/mongo/db/catalog/index_catalog.h
index 446a949ff2f..bd0c919076a 100644
--- a/src/mongo/db/catalog/index_catalog.h
+++ b/src/mongo/db/catalog/index_catalog.h
@@ -211,9 +211,10 @@ public:
 
     /**
      * Call this only on an empty collection from inside a WriteUnitOfWork. Index creation on an
-     * empty collection can be rolled back as part of a larger WUOW.
+     * empty collection can be rolled back as part of a larger WUOW. Returns the full specification
+     * of the created index, as it is stored in this index catalog.
      */
-    Status createIndexOnEmptyCollection(OperationContext* txn, BSONObj spec);
+    StatusWith<BSONObj> createIndexOnEmptyCollection(OperationContext* txn, BSONObj spec);
 
     StatusWith<BSONObj> prepareSpecForCreate(OperationContext* txn, const BSONObj& original) const;
 
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index 920eb9aa980..3f2f13d2db0 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -424,8 +424,9 @@ void State::prepTempCollection() {
                                            << "_temp_0"
                                            << "v"
                                            << static_cast<int>(IndexVersion::kV2));
-            Status status =
-                incColl->getIndexCatalog()->createIndexOnEmptyCollection(_txn, indexSpec);
+            Status status = incColl->getIndexCatalog()
+                                ->createIndexOnEmptyCollection(_txn, indexSpec)
+                                .getStatus();
             if (!status.isOK()) {
                 uasserted(17305,
                           str::stream() << "createIndex failed for mr incLong ns: "
@@ -486,7 +487,8 @@ void State::prepTempCollection() {
 
         for (vector<BSONObj>::iterator it = indexesToInsert.begin(); it != indexesToInsert.end();
              ++it) {
-            Status status = tempColl->getIndexCatalog()->createIndexOnEmptyCollection(_txn, *it);
+            Status status =
+                tempColl->getIndexCatalog()->createIndexOnEmptyCollection(_txn, *it).getStatus();
             if (!status.isOK()) {
                 if (status.code() == ErrorCodes::IndexAlreadyExists) {
                     continue;
diff --git a/src/mongo/db/op_observer.cpp b/src/mongo/db/op_observer.cpp
index 8defc1c71fe..99e1fe2f649 100644
--- a/src/mongo/db/op_observer.cpp
+++ b/src/mongo/db/op_observer.cpp
@@ -34,6 +34,7 @@
 #include "mongo/db/catalog/collection_options.h"
 #include "mongo/db/commands/dbhash.h"
 #include "mongo/db/commands/feature_compatibility_version.h"
+#include "mongo/db/index/index_descriptor.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/operation_context.h"
 #include "mongo/db/repl/oplog.h"
@@ -173,11 +174,23 @@ void OpObserver::onOpMessage(OperationContext* txn, const BSONObj& msgObj) {
 
 void OpObserver::onCreateCollection(OperationContext* txn,
                                     const NamespaceString& collectionName,
-                                    const CollectionOptions& options) {
+                                    const CollectionOptions& options,
+                                    const BSONObj& idIndex) {
     std::string dbName = collectionName.db().toString() + ".$cmd";
     BSONObjBuilder b;
     b.append("create", collectionName.coll().toString());
     b.appendElements(options.toBSON());
+
+    // Include the full _id index spec in the oplog for index versions >= 2.
+    if (!idIndex.isEmpty()) {
+        auto versionElem = idIndex[IndexDescriptor::kIndexVersionFieldName];
+        invariant(versionElem.isNumber());
+        if (IndexDescriptor::IndexVersion::kV2 <=
+            static_cast<IndexDescriptor::IndexVersion>(versionElem.numberInt())) {
+            b.append("idIndex", idIndex);
+        }
+    }
+
     BSONObj cmdObj = b.obj();
 
     if (!collectionName.isSystemDotProfile()) {
diff --git a/src/mongo/db/op_observer.h b/src/mongo/db/op_observer.h
index b5a2d926489..e9c6f7d7425 100644
--- a/src/mongo/db/op_observer.h
+++ b/src/mongo/db/op_observer.h
@@ -95,7 +95,8 @@ public:
     void onOpMessage(OperationContext* txn, const BSONObj& msgObj);
     void onCreateCollection(OperationContext* txn,
                             const NamespaceString& collectionName,
-                            const CollectionOptions& options);
+                            const CollectionOptions& options,
+                            const BSONObj& idIndex);
     void onCollMod(OperationContext* txn, const std::string& dbName, const BSONObj& collModCmd);
     void onDropDatabase(OperationContext* txn, const std::string& dbName);
     void onDropCollection(OperationContext* txn, const NamespaceString& collectionName);
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index cfd4b5792cc..a2fd477ab9d 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -575,7 +575,22 @@ struct ApplyOpMetadata {
 std::map<std::string, ApplyOpMetadata> opsMap = {
     {"create",
      {[](OperationContext* txn, const char* ns, BSONObj& cmd) -> Status {
-          return createCollection(txn, NamespaceString(ns).db().toString(), cmd);
+          const NamespaceString nss(parseNs(ns, cmd));
+          if (auto idIndexElem = cmd["idIndex"]) {
+              // Remove "idIndex" field from command.
+              auto cmdWithoutIdIndex = cmd.removeField("idIndex");
+              return createCollection(
+                  txn, nss.db().toString(), cmdWithoutIdIndex, idIndexElem.Obj());
+          }
+
+          // No _id index spec was provided, so we should build a v:1 _id index.
+          BSONObjBuilder idIndexSpecBuilder;
+          idIndexSpecBuilder.append(IndexDescriptor::kIndexVersionFieldName,
+                                    static_cast<int>(IndexVersion::kV1));
+          idIndexSpecBuilder.append(IndexDescriptor::kIndexNameFieldName, "_id_");
+          idIndexSpecBuilder.append(IndexDescriptor::kNamespaceFieldName, nss.ns());
+          idIndexSpecBuilder.append(IndexDescriptor::kKeyPatternFieldName, BSON("_id" << 1));
+          return createCollection(txn, nss.db().toString(), cmd, idIndexSpecBuilder.done());
       },
       {ErrorCodes::NamespaceExists}}},
     {"collMod", {[](OperationContext* txn, const char* ns, BSONObj& cmd) -> Status {