在nodejs中使用带有redlock和集群的cron

Question

我想每分钟运行一个任务，为此我选择了 cron。现在我正在使用集群模块运行节点，它产生了 4 个进程，但我想每分钟每个进程只运行一次 cron。

现在解决这个问题的一种方法是在 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，那将无济于事。

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，该作业会执行 4-5 次，这是我不想要的。任何帮助，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。

包链接：

1. Redlock
2. Cron

Answer 1

似乎如果一个实例在第二个实例尝试获取它之前获得了锁并释放它，那么两者都会运行。你需要一些更强大的东西。

我刚刚为node写了一个小模块cronivo，它使用了latestJs和redis，应该对你有用，至少它可以给你一些想法。