Node JS Bull Queue，使用并发处理多个作业

Question

我们如何使用Bull并发在Node JS队列中一次处理多个作业？ 现在，基于下面的代码示例，我们是否可以处理一次添加到队列中的多个作业？因为我当前的实现现在可以一一处理了，

并发性

https://github.com/OptimalBits/bull/blob/develop/REFERENCE.md#queueprocess

向Qeueue添加多个作业

  for(value of results.data) {
                    if(value.ImageList) {

                        //since image urls are comma delimited , we will split it to convert into an array
                        let ImageList = value.ImageList.split(',')

                        //adding jobs to th queue
                        queue.add({ ImageList: ImageList });
                    }
                }

处理作业

const downloadFiles = function () {

                queue.process(function processor(job, done) {

                    let List = job.data.ImageList
                    let promises = [];

                    let download = function (url, filename, callback) {

                        request.get(url)
                            .pipe(crypto.createHash('md5'))
                            .on('finish', function () {
                                let hash = this.read().toString('hex')

                                gfs.findOne({ md5: hash }, function (err, file) {
                                    if (!file) {

                                        const file = filename
                                        const fileStorage = gfs.createWriteStream({ filename: file, metadata: job.opts.VIN });

                                        request.get(url)
                                            .on('error', function (err) { console.log(err) })
                                            .pipe(fileStorage)
                                            .on('close', callback);

                                    } else {
                                        console.log("File already existed")
                                    }
                                });

                                if (callback) {
                                    callback(null, this.read());
                                }
                            });

                    };

                    List.forEach(function (str) {
                        let filename = str.split('/').pop();

                        console.log('Downloading ' + filename);

                        promises.push(new Promise(function p(resolve, reject) {

                            download(str, filename, function () {

                                console.log('Finished Downloading' + "" + filename);

                                resolve(filename);
                            });
                        }
                        ));
                    });

                    Promise.all(promises)
                        .then(function d(filenames) {
                            done(null, filenames);
                        })
                        .catch(function e(error) {
                            done(error);
                        })

                });

            }

Answer 1

docs you linked to explain this：

注意：如果未指定，则并发默认为1。

/**
 * Consider these as overloaded functions. Since method overloading doesn't exist in javacript
 * bull recognizes the desired function call by checking the parameters' types. Make sure you
 * comply with one of the below defined patterns.
 *
 * Note: Concurrency defaults to 1 if not specified.
 */
process(processor: ((job, done?) => Promise<any>) | string)
process(concurrency: number, processor: ((job, done?) => Promise<any>) | string)
process(name: string, processor: ((job, done?) => Promise<any>) | string)
process(name: string, concurrency: number, processor: ((job, done?) => Promise<any>) | string)

尝试设置更高的并发性：

 const workerConcurrency = 2;
 queue.process(workerConcurrency, function processor(job, done) {