Mongo Transaction Wrappers

transaction-utils.js

async function commitWithRetry(session) {
    try {
        await session.commitTransaction();
    } catch (error) {
        if (
            error.errorLabels &&
            error.errorLabels.includes('UnknownTransactionCommitResult')
        ) {
            log.error(
                'UnknownTransactionCommitResult, retrying commit operation ...'
            );
            await commitWithRetry(session);
        } else {
            log.error('Error during commit ...');
            throw error;
        }
    }
}

async function runTransactionWithRetry(txnFunc, session) {
    session.startTransaction();
    try {
        await txnFunc();
        await commitWithRetry(session);
    } catch (error) {
        await session.abortTransaction();
        log.error('Transaction aborted. Caught exception during transaction.');

        // If transient error, retry the whole transaction
        if (
            error.errorLabels &&
            error.errorLabels.includes('TransientTransactionError')
        ) {
            log.error('TransientTransactionError, retrying transaction ...');
            await runTransactionWithRetry(txnFunc);
        } else {
            throw error;
        }
    }
}

export const wrapInTransaction = (client, txnFunc) => async db => {
    const session = client.startSession();
    const innerFunc = () => txnFunc(db);
    try {
        await runTransactionWithRetry(innerFunc, session);
    } finally {
        await session.endSession();
    }
};