SERVER-47121: Introduce pre/post handshake error handling in the RSM

1 files changed, 210 insertions, 0 deletions

diff --git a/src/mongo/client/streamable_replica_set_monitor_error_handler_test.cpp b/src/mongo/client/streamable_replica_set_monitor_error_handler_test.cpp
new file mode 100644
index 00000000000..45aea46b787
--- /dev/null
+++ b/src/mongo/client/streamable_replica_set_monitor_error_handler_test.cpp
@@ -0,0 +1,210 @@
+/**
+ *    Copyright (C) 2020-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kNetwork
+#include "mongo/client/streamable_replica_set_monitor_error_handler.h"
+
+#include <boost/optional/optional_io.hpp>
+
+#include "mongo/client/sdam/sdam.h"
+#include "mongo/logv2/log.h"
+#include "mongo/platform/basic.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+using HandshakeStage = StreamableReplicaSetMonitorErrorHandler::HandshakeStage;
+using ErrorActions = StreamableReplicaSetMonitorErrorHandler::ErrorActions;
+using Error = ErrorCodes::Error;
+
+class StreamableReplicaSetMonitorErrorHandlerTestFixture : public unittest::Test {
+public:
+    Status makeStatus(Error error) {
+        return Status(error, kErrorMessage);
+    }
+
+    void verifyActions(ErrorActions result, ErrorActions expectedResult) {
+        ASSERT_EQUALS(result.dropConnections, expectedResult.dropConnections);
+        ASSERT_EQUALS(result.requestImmediateCheck, expectedResult.requestImmediateCheck);
+        if (expectedResult.isMasterOutcome) {
+            ASSERT_FALSE(result.isMasterOutcome->isSuccess());
+            std::string resultError = result.isMasterOutcome->getErrorMsg();
+            ASSERT_NOT_EQUALS(resultError.find(expectedResult.isMasterOutcome->getErrorMsg()),
+                              std::string::npos);
+        } else {
+            ASSERT_FALSE(result.isMasterOutcome);
+        }
+    }
+
+    void testScenario(HandshakeStage stage,
+                      bool isApplicationOperation,
+                      std::vector<Error> errors,
+                      std::function<ErrorActions(const Status&)> expectedResultGenerator,
+                      int numAttempts = 1) {
+        auto testSubject = subject();
+
+        const auto prePost = (stage == HandshakeStage::kPreHandshake) ? "pre" : "post";
+        const auto applicationOperation = (isApplicationOperation) ? "application" : "monitoring";
+        LOGV2_INFO(4712105,
+                   "Check Scenario",
+                   "handshake"_attr = prePost,
+                   "operationType"_attr = applicationOperation);
+        for (auto error : errors) {
+            LOGV2_INFO(4712106, "Check error ", "error"_attr = ErrorCodes::errorString(error));
+            for (int attempt = 0; attempt < numAttempts; attempt++) {
+                auto result = testSubject->computeErrorActions(
+                    kHost, makeStatus(error), stage, isApplicationOperation, kErrorBson);
+                verifyActions(result, expectedResultGenerator(makeStatus(error)));
+                LOGV2_INFO(4712107, "Attempt Successful", "num"_attr = attempt);
+            }
+        }
+    }
+
+    void testScenario(HandshakeStage stage,
+                      bool isApplicationOperation,
+                      std::vector<Error> errors,
+                      ErrorActions expectedResult,
+                      int numAttempts = 1) {
+        testScenario(stage, isApplicationOperation, errors, [expectedResult](const Status&) {
+            return expectedResult;
+        });
+    }
+
+    std::unique_ptr<StreamableReplicaSetMonitorErrorHandler> subject() {
+        return std::make_unique<SdamErrorHandler>(kSetName);
+    }
+
+    inline static const std::vector<Error> kNetworkErrors{ErrorCodes::SocketException,
+                                                          ErrorCodes::NetworkTimeout,
+                                                          ErrorCodes::HostNotFound,
+                                                          ErrorCodes::HostUnreachable};
+    inline static const std::vector<Error> kNetworkErrorsNoTimeout{
+        ErrorCodes::SocketException, ErrorCodes::HostNotFound, ErrorCodes::HostUnreachable};
+    inline static const std::vector<Error> kInternalError{ErrorCodes::InternalError};
+    inline static const std::vector<Error> kNotMasterAndNodeRecovering{
+        ErrorCodes::InterruptedAtShutdown,
+        ErrorCodes::InterruptedDueToReplStateChange,
+        ErrorCodes::NotMasterOrSecondary,
+        ErrorCodes::PrimarySteppedDown,
+        ErrorCodes::ShutdownInProgress,
+        ErrorCodes::NotMaster,
+        ErrorCodes::NotMasterNoSlaveOk};
+
+    inline static const std::string kSetName = "setName";
+    inline static const HostAndPort kHost = HostAndPort("foobar:123");
+    inline static const std::string kErrorMessage = "an error message";
+    inline static const BSONObj kErrorBson = BSONObjBuilder().append("ok", 0).obj();
+    inline static const sdam::IsMasterOutcome kErrorIsMasterOutcome =
+        sdam::IsMasterOutcome(kHost.toString(), kErrorBson, kErrorMessage);
+
+    static constexpr bool kApplicationOperation = true;
+    static constexpr bool kMonitoringOperation = false;
+
+    static constexpr int kThreeAttempts = 3;
+};
+
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture, ApplicationNetworkErrorsPreHandshake) {
+    testScenario(
+        HandshakeStage::kPreHandshake,
+        kApplicationOperation,
+        kNetworkErrors,
+        StreamableReplicaSetMonitorErrorHandler::ErrorActions{true, false, kErrorIsMasterOutcome});
+};
+
+// https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-discovery-and-monitoring.rst#network-error-when-reading-or-writing
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture, ApplicationNetworkErrorsPostHandshake) {
+    testScenario(
+        HandshakeStage::kPostHandshake,
+        kApplicationOperation,
+        kNetworkErrorsNoTimeout,
+        StreamableReplicaSetMonitorErrorHandler::ErrorActions{true, false, kErrorIsMasterOutcome});
+};
+
+// https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-monitoring.rst#network-error-during-server-check
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture, MonitoringNetworkErrorsPostHandshake) {
+    // Two consecutive errors must occur to expect an unknown server description.
+    const auto errorServerDescriptionOnSecondNetworkFailure = [](const Status& status) {
+        static int count = 0;
+        count = (count + 1) % 2;
+        return (count == 1)
+            ? StreamableReplicaSetMonitorErrorHandler::ErrorActions{true, true, boost::none}
+            : StreamableReplicaSetMonitorErrorHandler::ErrorActions{
+                  true, false, kErrorIsMasterOutcome};
+    };
+
+    testScenario(HandshakeStage::kPostHandshake,
+                 kMonitoringOperation,
+                 kNetworkErrors,
+                 errorServerDescriptionOnSecondNetworkFailure,
+                 kThreeAttempts);
+}
+
+// https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-monitoring.rst#network-error-during-server-check
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture, MonitoringNetworkErrorsPreHandshake) {
+    testScenario(
+        HandshakeStage::kPreHandshake,
+        kMonitoringOperation,
+        kNetworkErrors,
+        StreamableReplicaSetMonitorErrorHandler::ErrorActions{true, false, kErrorIsMasterOutcome},
+        kThreeAttempts);
+}
+
+// https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-discovery-and-monitoring.rst#not-master-and-node-is-recovering
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture, ApplicationNotMasterOrNodeRecovering) {
+    const auto shutdownErrorsDropConnections = [](const Status& status) {
+        if (ErrorCodes::isA<ErrorCategory::ShutdownError>(status.code())) {
+            return StreamableReplicaSetMonitorErrorHandler::ErrorActions{
+                true, true, kErrorIsMasterOutcome};
+        } else {
+            return StreamableReplicaSetMonitorErrorHandler::ErrorActions{
+                false, true, kErrorIsMasterOutcome};
+        }
+    };
+
+    testScenario(HandshakeStage::kPostHandshake,
+                 kApplicationOperation,
+                 kNotMasterAndNodeRecovering,
+                 shutdownErrorsDropConnections);
+}
+
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture, MonitoringNonNetworkError) {
+    testScenario(
+        HandshakeStage::kPostHandshake,
+        kMonitoringOperation,
+        kInternalError,
+        StreamableReplicaSetMonitorErrorHandler::ErrorActions{false, false, kErrorIsMasterOutcome});
+}
+
+TEST_F(StreamableReplicaSetMonitorErrorHandlerTestFixture,
+       ApplicationNonNetworkIsMasterOrRecoveringError) {
+    testScenario(
+        HandshakeStage::kPostHandshake,
+        kMonitoringOperation,
+        kInternalError,
+        StreamableReplicaSetMonitorErrorHandler::ErrorActions{false, false, kErrorIsMasterOutcome});
+}
+}  // namespace mongo