在nodejs中使用cron与redlock和集群

Question

我想每分钟运行一次任务，为此我选择了cron。现在，我使用集群模块运行节点，它生成了4个进程，但我希望每分钟只在每个进程上运行cron一次。

现在，解决这个问题的一个解决方案是在master中运行它。但是，如果我在每个实例上启动多个带有集群的实例，这将于事无补。

所以我决定寻找锁定机制。我找到了redlock，这是示例代码：

const redlock = new Redlock([redisClient], {
    driftFactor: 0.01, // time in ms
    retryCount: 2,
    retryDelay: 200 // time in ms
});

redlock.on('clientError', function (err) {
    console.error('REDLOCK REDIS ERROR: ', err);
});

const LOCK_KEY = "GOHAN_REMINDER_LOCK";
const LOCK_KEY_TTL = 10000;


const job = new CronJob({
    cronTime: '* * * * *',
    onTick: function () {
        /*
         * Runs every minute
         */
        redlock.lock(LOCK_KEY, LOCK_KEY_TTL).then(function (lock) {

            return Bluebird.try(function () {
                const currentMilitaryTime = moment.utc().format("HH:mm");

                return ChildReminder.getRemindersByDate(currentMilitaryTime).then(function (reminders) {
                    console.log("REMINDERS FOR TIME " + currentMilitaryTime + " :", reminders);
                });
            }).then(function () {
                return lock.unlock()
                    .catch(function (err) {
                        console.error("REDLOCK UNLOCK ERROR: ", err);
                    });
            });
        });

    },
    start: false,
    timeZone: 'UTC'
});

job.start();

我得到的日志：

REMINDERS FOR TIME 06:08 : [ anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 4,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399630',
    created_at: 2016-11-29T06:07:12.296Z,
    updated_at: 2016-11-29T06:07:12.296Z,
    time: '06:08',
    repeat: '1111111',
    on: true },
  anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 5,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399638',
    created_at: 2016-11-29T06:07:19.385Z,
    updated_at: 2016-11-29T06:07:19.385Z,
    time: '06:08',
    repeat: '1111111',
    on: true } ]
REMINDERS FOR TIME 06:08 : [ anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 4,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399630',
    created_at: 2016-11-29T06:07:12.296Z,
    updated_at: 2016-11-29T06:07:12.296Z,
    time: '06:08',
    repeat: '1111111',
    on: true },
  anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 5,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399638',
    created_at: 2016-11-29T06:07:19.385Z,
    updated_at: 2016-11-29T06:07:19.385Z,
    time: '06:08',
    repeat: '1111111',
    on: true } ]
REMINDERS FOR TIME 06:08 : [ anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 4,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399630',
    created_at: 2016-11-29T06:07:12.296Z,
    updated_at: 2016-11-29T06:07:12.296Z,
    time: '06:08',
    repeat: '1111111',
    on: true },
  anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 5,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399638',
    created_at: 2016-11-29T06:07:19.385Z,
    updated_at: 2016-11-29T06:07:19.385Z,
    time: '06:08',
    repeat: '1111111',
    on: true } ]
REMINDERS FOR TIME 06:08 : [ anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 4,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399630',
    created_at: 2016-11-29T06:07:12.296Z,
    updated_at: 2016-11-29T06:07:12.296Z,
    time: '06:08',
    repeat: '1111111',
    on: true },
  anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 5,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399638',
    created_at: 2016-11-29T06:07:19.385Z,
    updated_at: 2016-11-29T06:07:19.385Z,
    time: '06:08',
    repeat: '1111111',
    on: true } ]
REMINDERS FOR TIME 06:08 : [ anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 4,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399630',
    created_at: 2016-11-29T06:07:12.296Z,
    updated_at: 2016-11-29T06:07:12.296Z,
    time: '06:08',
    repeat: '1111111',
    on: true },
  anonymous {
    user_id: '764418c2-a874-495c-b8c1-cc555ce9b202',
    child_id: '8c8a273f-3a84-4a66-9fa7-bb9e6c5fcf0a',
    reminder_id: 5,
    label: 'textvoice1',
    mode: 'textvoice',
    text_message: 'How you doin\'',
    voice_message: '1480399638',
    created_at: 2016-11-29T06:07:19.385Z,
    updated_at: 2016-11-29T06:07:19.385Z,
    time: '06:08',
    repeat: '1111111',
    on: true } ]

基本上，这项工作是执行4-5倍，我不想。任何帮助都将不胜感激。谢谢。

编辑1:我尝试将retryCount更改为0并增加/减少TTL，但没有得到我想要的结果。

与软件包的链接：

1. 雷德洛克
2. 克隆

Answer 1

看起来，如果一个实例在第二个实例尝试获取锁之前获得并释放了它，那么这两个实例都将运行。你需要一些更健壮的东西。

我刚刚为节点编写了一个小模块，克罗尼沃，它使用了后置just和redis，它应该适合您，至少它可以给您一些想法。