Revert "SERVER-70127 change system operation threads to be killable by default"

This reverts commit 9f2867c9da77e2d64df3852f7d4578f10e6f0817.

Revert "SERVER-75352 OplogBatcher's ReplBatcher thread should be unkillable"

This reverts commit 26266d5b736f90961a328399dea5d299cd407ab2.

15 files changed, 18 insertions, 71 deletions

diff --git a/src/mongo/db/repl/bgsync.cpp b/src/mongo/db/repl/bgsync.cpp
index 3d7c0b325d3..340aca59e80 100644
--- a/src/mongo/db/repl/bgsync.cpp
+++ b/src/mongo/db/repl/bgsync.cpp
@@ -226,11 +226,6 @@ void BackgroundSync::_run() {
     Client::initThread("BackgroundSync");
     AuthorizationSession::get(cc())->grantInternalAuthorization(&cc());
 
-    {
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
-
     while (!inShutdown()) {
         try {
             _runProducer();
diff --git a/src/mongo/db/repl/noop_writer.cpp b/src/mongo/db/repl/noop_writer.cpp
index 74a3312c30a..4bf8188010b 100644
--- a/src/mongo/db/repl/noop_writer.cpp
+++ b/src/mongo/db/repl/noop_writer.cpp
@@ -83,7 +83,6 @@ public:
 private:
     void run(Seconds waitTime, NoopWriteFn noopWrite) {
         Client::initThread("NoopWriter");
-
         while (true) {
             const ServiceContext::UniqueOperationContext opCtxPtr = cc().makeOperationContext();
             OperationContext& opCtx = *opCtxPtr;
diff --git a/src/mongo/db/repl/oplog_applier.cpp b/src/mongo/db/repl/oplog_applier.cpp
index 2d0493e5c39..af33eaf9633 100644
--- a/src/mongo/db/repl/oplog_applier.cpp
+++ b/src/mongo/db/repl/oplog_applier.cpp
@@ -171,9 +171,9 @@ std::unique_ptr<ThreadPool> makeReplWriterPool(int threadCount,
         auto client = Client::getCurrent();
         AuthorizationSession::get(*client)->grantInternalAuthorization(client);
 
-        if (!isKillableByStepdown) {
+        if (isKillableByStepdown) {
             stdx::lock_guard<Client> lk(*client);
-            client->setSystemOperationUnKillableByStepdown(lk);
+            client->setSystemOperationKillableByStepdown(lk);
         }
     };
     auto pool = std::make_unique<ThreadPool>(options);
diff --git a/src/mongo/db/repl/oplog_applier_impl.cpp b/src/mongo/db/repl/oplog_applier_impl.cpp
index 83c15ae106c..7617e6afd46 100644
--- a/src/mongo/db/repl/oplog_applier_impl.cpp
+++ b/src/mongo/db/repl/oplog_applier_impl.cpp
@@ -285,11 +285,6 @@ void ApplyBatchFinalizerForJournal::record(const OpTimeAndWallTime& newOpTimeAnd
 void ApplyBatchFinalizerForJournal::_run() {
     Client::initThread("ApplyBatchFinalizerForJournal");
 
-    {
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
-
     while (true) {
         OpTimeAndWallTime latestOpTimeAndWallTime = {OpTime(), Date_t()};
 
diff --git a/src/mongo/db/repl/oplog_batcher.cpp b/src/mongo/db/repl/oplog_batcher.cpp
index f606c0bae03..9d5edbd2bb5 100644
--- a/src/mongo/db/repl/oplog_batcher.cpp
+++ b/src/mongo/db/repl/oplog_batcher.cpp
@@ -273,13 +273,6 @@ void OplogBatcher::_consume(OperationContext* opCtx, OplogBuffer* oplogBuffer) {
 void OplogBatcher::_run(StorageInterface* storageInterface) {
     Client::initThread("ReplBatcher");
 
-    {
-        // The OplogBatcher's thread has its own shutdown sequence triggered by the OplogApplier,
-        // so we don't want it to be killed in other ways.
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
-
     BatchLimits batchLimits;
 
     while (true) {
diff --git a/src/mongo/db/repl/primary_only_service.cpp b/src/mongo/db/repl/primary_only_service.cpp
index b3513e481fa..44c2d446cbf 100644
--- a/src/mongo/db/repl/primary_only_service.cpp
+++ b/src/mongo/db/repl/primary_only_service.cpp
@@ -335,6 +335,9 @@ void PrimaryOnlyService::startup(OperationContext* opCtx) {
         auto client = Client::getCurrent();
         AuthorizationSession::get(*client)->grantInternalAuthorization(&cc());
 
+        stdx::lock_guard<Client> lk(*client);
+        client->setSystemOperationKillableByStepdown(lk);
+
         // Associate this Client with this PrimaryOnlyService
         primaryOnlyServiceStateForClient(client).primaryOnlyService = this;
     };
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index 7342f419fb7..fabe5d1f02e 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -147,12 +147,6 @@ auto makeThreadPool(const std::string& poolName, const std::string& threadName)
     threadPoolOptions.poolName = poolName;
     threadPoolOptions.onCreateThread = [](const std::string& threadName) {
         Client::initThread(threadName.c_str());
-
-        {
-            stdx::lock_guard<Client> lk(cc());
-            cc().setSystemOperationUnKillableByStepdown(lk);
-        }
-
         AuthorizationSession::get(cc())->grantInternalAuthorization(&cc());
     };
     return std::make_unique<ThreadPool>(threadPoolOptions);
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 113f911bc0d..83be62085c9 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -2651,11 +2651,6 @@ void ReplicationCoordinatorImpl::AutoGetRstlForStepUpStepDown::_killOpThreadFn()
 
     invariant(!cc().isFromUserConnection());
 
-    {
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
-
     LOGV2(21343, "Starting to kill user operations");
     auto uniqueOpCtx = cc().makeOperationContext();
     OperationContext* opCtx = uniqueOpCtx.get();
diff --git a/src/mongo/db/repl/replication_coordinator_test_fixture.cpp b/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
index 291383fef85..744e1cf824f 100644
--- a/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
+++ b/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
@@ -116,10 +116,7 @@ void ReplCoordTest::addSelf(const HostAndPort& selfHost) {
 void ReplCoordTest::init() {
     invariant(!_repl);
     invariant(!_callShutdown);
-    {
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
+
     auto service = getGlobalServiceContext();
     _storageInterface = new StorageInterfaceMock();
     StorageInterface::set(service, std::unique_ptr<StorageInterface>(_storageInterface));
@@ -163,9 +160,6 @@ void ReplCoordTest::init() {
     executor::ThreadPoolMock::Options tpOptions;
     tpOptions.onCreateThread = []() {
         Client::initThread("replexec");
-
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
     };
     auto pool = std::make_unique<executor::ThreadPoolMock>(_net, seed, tpOptions);
     auto replExec =
diff --git a/src/mongo/db/repl/rollback_test_fixture.cpp b/src/mongo/db/repl/rollback_test_fixture.cpp
index 511bf2fc298..f88973b38b9 100644
--- a/src/mongo/db/repl/rollback_test_fixture.cpp
+++ b/src/mongo/db/repl/rollback_test_fixture.cpp
@@ -88,10 +88,7 @@ public:
 
 void RollbackTest::setUp() {
     ServiceContextMongoDTest::setUp();
-    {
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
+
     _storageInterface = new StorageInterfaceRollback();
     auto serviceContext = getServiceContext();
     auto consistencyMarkers = std::make_unique<ReplicationConsistencyMarkersMock>();
diff --git a/src/mongo/db/repl/storage_interface_impl.cpp b/src/mongo/db/repl/storage_interface_impl.cpp
index b1d42571985..0c8a3614aed 100644
--- a/src/mongo/db/repl/storage_interface_impl.cpp
+++ b/src/mongo/db/repl/storage_interface_impl.cpp
@@ -225,12 +225,6 @@ StorageInterfaceImpl::createCollectionForBulkLoading(
     auto opCtx = cc().makeOperationContext();
     opCtx->setEnforceConstraints(false);
 
-    // TODO(SERVER-74656): Please revisit if this thread could be made killable.
-    {
-        stdx::lock_guard<Client> lk(cc());
-        cc().setSystemOperationUnKillableByStepdown(lk);
-    }
-
     // DocumentValidationSettings::kDisableInternalValidation is currently inert.
     // But, it's logically ok to disable internal validation as this function gets called
     // only during initial sync.
diff --git a/src/mongo/db/repl/tenant_migration_donor_service.cpp b/src/mongo/db/repl/tenant_migration_donor_service.cpp
index 0cac61b3888..1775b8479a1 100644
--- a/src/mongo/db/repl/tenant_migration_donor_service.cpp
+++ b/src/mongo/db/repl/tenant_migration_donor_service.cpp
@@ -382,6 +382,17 @@ TenantMigrationDonorService::Instance::_makeRecipientCmdExecutor() {
         Client::initThread(threadName.c_str());
         auto client = Client::getCurrent();
         AuthorizationSession::get(*client)->grantInternalAuthorization(&cc());
+
+        // Ideally, we should also associate the client created by _recipientCmdExecutor with the
+        // TenantMigrationDonorService to make the opCtxs created by the task executor get
+        // registered in the TenantMigrationDonorService, and killed on stepdown. But that would
+        // require passing the pointer to the TenantMigrationService into the Instance and making
+        // constructInstance not const so we can set the client's decoration here. Right now there
+        // is no need for that since the task executor is only used with scheduleRemoteCommand and
+        // no opCtx will be created (the cancellation token is responsible for canceling the
+        // outstanding work on the task executor).
+        stdx::lock_guard<Client> lk(*client);
+        client->setSystemOperationKillableByStepdown(lk);
     };
 
     auto hookList = std::make_unique<rpc::EgressMetadataHookList>();
diff --git a/src/mongo/db/repl/topology_version_observer.cpp b/src/mongo/db/repl/topology_version_observer.cpp
index 4c29ec8d972..07eb6c5f327 100644
--- a/src/mongo/db/repl/topology_version_observer.cpp
+++ b/src/mongo/db/repl/topology_version_observer.cpp
@@ -178,12 +178,6 @@ void TopologyVersionObserver::_workerThreadBody() noexcept try {
     invariant(_serviceContext);
     ThreadClient tc(kTopologyVersionObserverName, _serviceContext);
 
-    // TODO(SERVER-74656): Please revisit if this thread could be made killable.
-    {
-        stdx::lock_guard<Client> lk(*tc.get());
-        tc.get()->setSystemOperationUnKillableByStepdown(lk);
-    }
-
     auto getTopologyVersion = [&]() -> boost::optional<TopologyVersion> {
         // Only the observer thread updates `_cache`, thus there is no need to hold the lock before
         // accessing `_cache` here.
diff --git a/src/mongo/db/repl/transaction_oplog_application.cpp b/src/mongo/db/repl/transaction_oplog_application.cpp
index 0ae8e8b5a02..458691eaade 100644
--- a/src/mongo/db/repl/transaction_oplog_application.cpp
+++ b/src/mongo/db/repl/transaction_oplog_application.cpp
@@ -794,13 +794,6 @@ void reconstructPreparedTransactions(OperationContext* opCtx, repl::OplogApplica
             // transaction oplog entry.
             auto newClient =
                 opCtx->getServiceContext()->makeClient("reconstruct-prepared-transactions");
-
-            // TODO(SERVER-74656): Please revisit if this thread could be made killable.
-            {
-                stdx::lock_guard<Client> lk(*newClient.get());
-                newClient.get()->setSystemOperationUnKillableByStepdown(lk);
-            }
-
             AlternativeClientRegion acr(newClient);
             const auto newOpCtx = cc().makeOperationContext();
 
diff --git a/src/mongo/db/repl/wait_for_majority_service.cpp b/src/mongo/db/repl/wait_for_majority_service.cpp
index 37b34f35d1c..37d6407e0fe 100644
--- a/src/mongo/db/repl/wait_for_majority_service.cpp
+++ b/src/mongo/db/repl/wait_for_majority_service.cpp
@@ -107,16 +107,6 @@ void WaitForMajorityServiceImplBase::startup(ServiceContext* ctx) {
         ClientStrand::make(ctx->makeClient(kWaitClientName + _getReadOrWrite()));
     _waitForMajorityCancellationClient =
         ClientStrand::make(ctx->makeClient(kCancelClientName + _getReadOrWrite()));
-    // TODO(SERVER-74656): Please revisit if this thread could be made killable.
-    {
-        stdx::lock_guard<Client> lk(*_waitForMajorityClient->getClientPointer());
-        _waitForMajorityClient->getClientPointer()->setSystemOperationUnKillableByStepdown(lk);
-    }
-    {
-        stdx::lock_guard<Client> lk(*_waitForMajorityCancellationClient->getClientPointer());
-        _waitForMajorityCancellationClient->getClientPointer()
-            ->setSystemOperationUnKillableByStepdown(lk);
-    }
     _backgroundWorkComplete = _periodicallyWaitForMajority();
     _pool->startup();
     _state = State::kRunning;