path: root/src/mongo/db/commands/txn_cmds.cpp

/**
 *    Copyright (C) 2018-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.
 */


#include "mongo/platform/basic.h"

#include "mongo/bson/bsonobj.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/txn_cmds_gen.h"
#include "mongo/db/curop_failpoint_helpers.h"
#include "mongo/db/op_observer/op_observer.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/repl_client_info.h"
#include "mongo/db/s/sharding_state.h"
#include "mongo/db/s/transaction_coordinator_service.h"
#include "mongo/db/service_context.h"
#include "mongo/db/transaction/transaction_participant.h"
#include "mongo/db/transaction_validation.h"
#include "mongo/logv2/log.h"

#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kTransaction


namespace mongo {
namespace {

MONGO_FAIL_POINT_DEFINE(participantReturnNetworkErrorForAbortAfterExecutingAbortLogic);
MONGO_FAIL_POINT_DEFINE(participantReturnNetworkErrorForCommitAfterExecutingCommitLogic);
MONGO_FAIL_POINT_DEFINE(hangBeforeCommitingTxn);
MONGO_FAIL_POINT_DEFINE(hangBeforeAbortingTxn);
// TODO SERVER-39704: Remove this fail point once the router can safely retry within a transaction
// on stale version and snapshot errors.
MONGO_FAIL_POINT_DEFINE(dontRemoveTxnCoordinatorOnAbort);

class CmdCommitTxn final : public CommitTransactionCmdVersion1Gen<CmdCommitTxn> {
public:
    CmdCommitTxn() = default;

    AllowedOnSecondary secondaryAllowed(ServiceContext*) const final {
        return AllowedOnSecondary::kNever;
    }

    bool adminOnly() const final {
        return true;
    }

    bool collectsResourceConsumptionMetrics() const final {
        return true;
    }

    std::string help() const final {
        return "Commits a transaction";
    }

    bool isTransactionCommand() const final {
        return true;
    }

    bool allowedInTransactions() const final {
        return true;
    }

    bool allowedWithSecurityToken() const final {
        return true;
    }

    class Invocation final : public InvocationBaseGen {
    public:
        using InvocationBaseGen::InvocationBaseGen;

        bool supportsWriteConcern() const final {
            return true;
        }

        NamespaceString ns() const final {
            return NamespaceString(request().getDbName());
        }

        Reply typedRun(OperationContext* opCtx) final {
            auto txnParticipant = TransactionParticipant::get(opCtx);
            uassert(ErrorCodes::CommandFailed,
                    "commitTransaction must be run within a transaction",
                    txnParticipant);

            const TxnNumberAndRetryCounter txnNumberAndRetryCounter{*opCtx->getTxnNumber(),
                                                                    *opCtx->getTxnRetryCounter()};

            LOGV2_DEBUG(20507,
                        3,
                        "Received commitTransaction for transaction with "
                        "{txnNumberAndRetryCounter} on session {sessionId}",
                        "Received commitTransaction",
                        "txnNumberAndRetryCounter"_attr = txnNumberAndRetryCounter,
                        "sessionId"_attr = opCtx->getLogicalSessionId()->toBSON());

            // commitTransaction is retryable.
            if (txnParticipant.transactionIsCommitted()) {
                // We set the client last op to the last optime observed by the system to ensure
                // that we wait for the specified write concern on an optime greater than or equal
                // to the commit oplog entry.
                auto& replClient = repl::ReplClientInfo::forClient(opCtx->getClient());
                replClient.setLastOpToSystemLastOpTime(opCtx);
                if (MONGO_unlikely(participantReturnNetworkErrorForCommitAfterExecutingCommitLogic
                                       .shouldFail())) {
                    uasserted(ErrorCodes::HostUnreachable,
                              "returning network error because failpoint is on");
                }

                return Reply();
            }

            uassert(ErrorCodes::NoSuchTransaction,
                    "Transaction isn't in progress",
                    txnParticipant.transactionIsOpen());

            CurOpFailpointHelpers::waitWhileFailPointEnabled(
                &hangBeforeCommitingTxn, opCtx, "hangBeforeCommitingTxn");

            auto optionalCommitTimestamp = request().getCommitTimestamp();
            if (optionalCommitTimestamp) {
                // commitPreparedTransaction will throw if the transaction is not prepared.
                txnParticipant.commitPreparedTransaction(
                    opCtx, optionalCommitTimestamp.value(), {});
            } else {
                if (ShardingState::get(opCtx)->canAcceptShardedCommands().isOK() ||
                    serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
                    TransactionCoordinatorService::get(opCtx)->cancelIfCommitNotYetStarted(
                        opCtx, *opCtx->getLogicalSessionId(), txnNumberAndRetryCounter);
                }

                // commitUnpreparedTransaction will throw if the transaction is prepared.
                txnParticipant.commitUnpreparedTransaction(opCtx);
            }

            if (MONGO_unlikely(
                    participantReturnNetworkErrorForCommitAfterExecutingCommitLogic.shouldFail())) {
                uasserted(ErrorCodes::HostUnreachable,
                          "returning network error because failpoint is on");
            }

            return Reply();
        }
    };

} commitTxn;

static const Status kOnlyTransactionsReadConcernsSupported{
    ErrorCodes::InvalidOptions, "only read concerns valid in transactions are supported"};
static const Status kDefaultReadConcernNotPermitted{ErrorCodes::InvalidOptions,
                                                    "default read concern not permitted"};

class CmdAbortTxn final : public AbortTransactionCmdVersion1Gen<CmdAbortTxn> {
public:
    CmdAbortTxn() = default;

    AllowedOnSecondary secondaryAllowed(ServiceContext*) const final {
        return AllowedOnSecondary::kNever;
    }

    bool adminOnly() const final {
        return true;
    }

    bool collectsResourceConsumptionMetrics() const final {
        return true;
    }

    std::string help() const final {
        return "Aborts a transaction";
    }

    bool isTransactionCommand() const final {
        return true;
    }

    bool allowedInTransactions() const final {
        return true;
    }

    bool allowedWithSecurityToken() const final {
        return true;
    }

    class Invocation final : public InvocationBaseGen {
    public:
        using InvocationBaseGen::InvocationBaseGen;

        bool supportsWriteConcern() const final {
            return true;
        }

        ReadConcernSupportResult supportsReadConcern(repl::ReadConcernLevel level,
                                                     bool isImplicitDefault) const final {
            // abortTransaction commences running inside a transaction (even though the transaction
            // will be ended by the time it completes).  Therefore it needs to accept any
            // readConcern which is valid within a transaction.  However it is not appropriate to
            // apply the default readConcern, since the readConcern of the transaction (set by the
            // first operation) is what must apply.
            return {{!isReadConcernLevelAllowedInTransaction(level),
                     kOnlyTransactionsReadConcernsSupported},
                    {kDefaultReadConcernNotPermitted}};
        }

        NamespaceString ns() const final {
            return NamespaceString(request().getDbName());
        }

        Reply typedRun(OperationContext* opCtx) final {
            auto txnParticipant = TransactionParticipant::get(opCtx);
            uassert(ErrorCodes::CommandFailed,
                    "abortTransaction must be run within a transaction",
                    txnParticipant);

            const TxnNumberAndRetryCounter txnNumberAndRetryCounter{*opCtx->getTxnNumber(),
                                                                    *opCtx->getTxnRetryCounter()};

            LOGV2_DEBUG(20508,
                        3,
                        "Received abortTransaction for transaction with {txnNumberAndRetryCounter} "
                        "on session {sessionId}",
                        "Received abortTransaction",
                        "txnNumberAndRetryCounter"_attr = txnNumberAndRetryCounter,
                        "sessionId"_attr = opCtx->getLogicalSessionId()->toBSON());

            uassert(ErrorCodes::NoSuchTransaction,
                    "Transaction isn't in progress",
                    txnParticipant.transactionIsOpen());

            CurOpFailpointHelpers::waitWhileFailPointEnabled(
                &hangBeforeAbortingTxn, opCtx, "hangBeforeAbortingTxn");

            if (!MONGO_unlikely(dontRemoveTxnCoordinatorOnAbort.shouldFail()) &&
                (ShardingState::get(opCtx)->canAcceptShardedCommands().isOK() ||
                 serverGlobalParams.clusterRole == ClusterRole::ConfigServer)) {
                TransactionCoordinatorService::get(opCtx)->cancelIfCommitNotYetStarted(
                    opCtx, *opCtx->getLogicalSessionId(), txnNumberAndRetryCounter);
            }

            txnParticipant.abortTransaction(opCtx);

            if (MONGO_unlikely(
                    participantReturnNetworkErrorForAbortAfterExecutingAbortLogic.shouldFail())) {
                uasserted(ErrorCodes::HostUnreachable,
                          "returning network error because failpoint is on");
            }

            return Reply();
        }
    };
} abortTxn;

}  // namespace
}  // namespace mongo