SERVER-27067 Remove unnecessary references to setLastOpToSystemLastOpTime

(cherry picked from commit 50cbe6d35a3b61ce674eb0d8fae173f70f1dddd5)

5 files changed, 9 insertions, 66 deletions

diff --git a/src/mongo/db/commands/apply_ops_cmd.cpp b/src/mongo/db/commands/apply_ops_cmd.cpp
index c252b8fd073..262e8ef93d3 100644
--- a/src/mongo/db/commands/apply_ops_cmd.cpp
+++ b/src/mongo/db/commands/apply_ops_cmd.cpp
@@ -116,22 +116,17 @@ public:
             }
         }
 
-        auto client = txn->getClient();
-        auto lastOpAtOperationStart = repl::ReplClientInfo::forClient(client).getLastOp();
-        ScopeGuard lastOpSetterGuard =
-            MakeObjGuard(repl::ReplClientInfo::forClient(client),
-                         &repl::ReplClientInfo::setLastOpToSystemLastOpTime,
-                         txn);
-
+        // TODO (SERVER-30217): When a write concern is provided to the applyOps command, we
+        // normally wait on the OpTime of whichever operation successfully completed last. This is
+        // erroneous, however, if the last operation in the array happens to be a write no-op and
+        // thus isn’t assigned an OpTime. Let the second to last operation in the applyOps be write
+        // A, the last operation in applyOps be write B. Let B do a no-op write and let the
+        // operation that caused B to be a no-op be C. If C has an OpTime after A but before B,
+        // then we won’t wait for C to be replicated and it could be rolled back, even though B
+        // was acknowledged. To fix this, we should wait for replication of the node’s last applied
+        // OpTime if the last write operation was a no-op write.
         auto applyOpsStatus = appendCommandStatus(result, applyOps(txn, dbname, cmdObj, &result));
 
-        if (repl::ReplClientInfo::forClient(client).getLastOp() != lastOpAtOperationStart) {
-            // If this operation has already generated a new lastOp, don't bother setting it
-            // here. No-op applyOps will not generate a new lastOp, so we still need the guard to
-            // fire in that case.
-            lastOpSetterGuard.Dismiss();
-        }
-
         return applyOpsStatus;
     }
 
diff --git a/src/mongo/db/commands/create_indexes.cpp b/src/mongo/db/commands/create_indexes.cpp
index 489e080f7a6..ee0133da46b 100644
--- a/src/mongo/db/commands/create_indexes.cpp
+++ b/src/mongo/db/commands/create_indexes.cpp
@@ -290,12 +290,6 @@ public:
         const int numIndexesBefore = collection->getIndexCatalog()->numIndexesTotal(txn);
         result.append("numIndexesBefore", numIndexesBefore);
 
-        auto client = txn->getClient();
-        ScopeGuard lastOpSetterGuard =
-            MakeObjGuard(repl::ReplClientInfo::forClient(client),
-                         &repl::ReplClientInfo::setLastOpToSystemLastOpTime,
-                         txn);
-
         MultiIndexBlock indexer(txn, collection);
         indexer.allowBackgroundBuilding();
         indexer.allowInterruption();
@@ -403,8 +397,6 @@ public:
 
         result.append("numIndexesAfter", collection->getIndexCatalog()->numIndexesTotal(txn));
 
-        lastOpSetterGuard.Dismiss();
-
         return true;
     }
 
diff --git a/src/mongo/db/commands/find_and_modify.cpp b/src/mongo/db/commands/find_and_modify.cpp
index 79ee34203ce..61dbc4f6509 100644
--- a/src/mongo/db/commands/find_and_modify.cpp
+++ b/src/mongo/db/commands/find_and_modify.cpp
@@ -364,18 +364,6 @@ public:
         if (shouldBypassDocumentValidationForCommand(cmdObj))
             maybeDisableValidation.emplace(txn);
 
-        auto client = txn->getClient();
-        auto lastOpAtOperationStart = repl::ReplClientInfo::forClient(client).getLastOp();
-        ScopeGuard lastOpSetterGuard =
-            MakeObjGuard(repl::ReplClientInfo::forClient(client),
-                         &repl::ReplClientInfo::setLastOpToSystemLastOpTime,
-                         txn);
-
-        // If this is the local database, don't set last op.
-        if (dbName == "local") {
-            lastOpSetterGuard.Dismiss();
-        }
-
         auto curOp = CurOp::get(txn);
         OpDebug* opDebug = &curOp->debug();
 
@@ -567,13 +555,6 @@ public:
         }
         MONGO_WRITE_CONFLICT_RETRY_LOOP_END(txn, "findAndModify", nsString.ns());
 
-        if (repl::ReplClientInfo::forClient(client).getLastOp() != lastOpAtOperationStart) {
-            // If this operation has already generated a new lastOp, don't bother setting it here.
-            // No-op updates will not generate a new lastOp, so we still need the guard to fire in
-            // that case.
-            lastOpSetterGuard.Dismiss();
-        }
-
         return true;
     }
 
diff --git a/src/mongo/db/ops/delete.cpp b/src/mongo/db/ops/delete.cpp
index 7f509308ad4..6a7da15ee74 100644
--- a/src/mongo/db/ops/delete.cpp
+++ b/src/mongo/db/ops/delete.cpp
@@ -63,19 +63,11 @@ long long deleteObjects(OperationContext* txn,
     ParsedDelete parsedDelete(txn, &request);
     uassertStatusOK(parsedDelete.parseRequest());
 
-    auto client = txn->getClient();
-    auto lastOpAtOperationStart = repl::ReplClientInfo::forClient(client).getLastOp();
-
     std::unique_ptr<PlanExecutor> exec = uassertStatusOK(
         getExecutorDelete(txn, &CurOp::get(txn)->debug(), collection, &parsedDelete));
 
     uassertStatusOK(exec->executePlan());
 
-    // No-ops need to reset lastOp in the client, for write concern.
-    if (repl::ReplClientInfo::forClient(client).getLastOp() == lastOpAtOperationStart) {
-        repl::ReplClientInfo::forClient(client).setLastOpToSystemLastOpTime(txn);
-    }
-
     return DeleteStage::getNumDeleted(*exec);
 }
 
diff --git a/src/mongo/db/ops/update.cpp b/src/mongo/db/ops/update.cpp
index 5e0763f9eac..bc3c595dc6c 100644
--- a/src/mongo/db/ops/update.cpp
+++ b/src/mongo/db/ops/update.cpp
@@ -63,20 +63,9 @@ UpdateResult update(OperationContext* txn, Database* db, const UpdateRequest& re
     // Explain should never use this helper.
     invariant(!request.isExplain());
 
-    auto client = txn->getClient();
-    auto lastOpAtOperationStart = repl::ReplClientInfo::forClient(client).getLastOp();
-    ScopeGuard lastOpSetterGuard = MakeObjGuard(repl::ReplClientInfo::forClient(client),
-                                                &repl::ReplClientInfo::setLastOpToSystemLastOpTime,
-                                                txn);
-
     const NamespaceString& nsString = request.getNamespaceString();
     Collection* collection = db->getCollection(nsString.ns());
 
-    // If this is the local database, don't set last op.
-    if (db->name() == "local") {
-        lastOpSetterGuard.Dismiss();
-    }
-
     // The update stage does not create its own collection.  As such, if the update is
     // an upsert, create the collection that the update stage inserts into beforehand.
     if (!collection && request.isUpsert()) {
@@ -116,12 +105,6 @@ UpdateResult update(OperationContext* txn, Database* db, const UpdateRequest& re
         uassertStatusOK(getExecutorUpdate(txn, nullOpDebug, collection, &parsedUpdate));
 
     uassertStatusOK(exec->executePlan());
-    if (repl::ReplClientInfo::forClient(client).getLastOp() != lastOpAtOperationStart) {
-        // If this operation has already generated a new lastOp, don't bother setting it here.
-        // No-op updates will not generate a new lastOp, so we still need the guard to fire in that
-        // case.
-        lastOpSetterGuard.Dismiss();
-    }
 
     const UpdateStats* updateStats = UpdateStage::getUpdateStats(exec.get());