cron fails on two servers, approximately same time, without error

I have two aws servers, identical setup:
lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 18.04.2 LTS Release: 18.04 Codename: bionic
uname -r 4.15.0-1035-aws
node --version v8.16.0
cat package.json | grep cron "cron": "^1.7.1",

both have cron running with this code:
new CronJob('*/10 * * * * *', procNewBlock, null, true, 'Europe/Berlin');

both stopped running at approximately the same time, the first was running the last time at:
May 2 09:05:47 UTC

the second last run was at:
May 2 09:06:30 UTC

so far this was the only time that this happend (running for about 1 month now). To me it looks as if some scheduled system task outside of nodejs is killing the crons. But any help greatly appreciated. The nodejs processes did not see any interruption.

probably related:
#231
#232

For me, it does not seem to depend on the server load: one of my servers is rather idle, the other rather busy. Both have the same resources.
Also, even though both crons stopped at almost the same time, their starting times are more than 1 day apart.

[ncb000gt]

That's really strange. Is there a service that both crons are using? What I'm wondering is if there is a possibility that they were using the same service that went down at some time which caused an exception in your calling code which cascaded and caused the crons to die.

Let me know, thanks!

Both servers synchronize to the ubuntu time server every 30 min, but at different times. However, sometimes the synchronization shows some timeouts (10s) - see the second log - which are longer than the cron interval. Could this be a problem?

Server 1:
09:00:57 May 2 09:00:57 ip-10-0-0-162 systemd-timesyncd[6168]: Network configuration changed, trying to establish connection. May 2 09:00:57 ip-10-0-0-162 systemd-timesyncd[6168]: Network configuration changed, trying to establish connection. 09:00:57 May 2 09:00:57 ip-10-0-0-162 systemd-timesyncd[6168]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com).

Server 2:
May 2 09:18:17 ip-10-0-0-7 systemd-timesyncd[23072]: Network configuration changed, trying to establish connection. May 2 09:18:17 ip-10-0-0-7 systemd-timesyncd[23072]: Network configuration changed, trying to establish connection. 09:18:27 May 2 09:18:27 ip-10-0-0-7 systemd-timesyncd[23072]: Timed out waiting for reply from 91.189.89.199:123 (ntp.ubuntu.com). 09:18:27 May 2 09:18:27 ip-10-0-0-7 systemd-timesyncd[23072]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com).

[jSherz]

Hi @ChristophDFine . Did you ever get to the bottom of what caused this?

No, not yet. I am still waiting that it happens again so I get more debug info.
So far it happened once more, which showed me that:
a) it is actually not related to the cron package but some deeper source in nodejs
b) it was probably a coincidence that it happend on both servers at the same time

[eero-lehtinen]

Hey,
I've had the exact same issue. Once a month timers would just stop working. Turned out that node v10 has an integer overflow issue that kills all timers after 25 days. It's fixed in v10.9.

Edit: might not be the same issue since your processes were launched at different times and stopped at the same time.

[ncb000gt]

Has anyone been able to reproduce this issue? If not I'll close the issue and chalk it up to a node issue.

Let me know. Thanks.

[EdClaus]

This morning I got this same error and tried out with a fresh new install of rasbian and node-red. I was able to pinpoint it to an inject node with specific content. With this (below) node it crashed, with other configurated inject nodes there are no problems.

[{"id":"a02e32cd.28c53","type":"tab","label":"Flow 6","disabled":false,"info":""},{"id":"a78a0f31.f1bc9","type":"inject","z":"a02e32cd.28c53","name":"Init & reset","topic":"","payload":"auto","payloadType":"str","repeat":"","crontab":"*/20 2 * * *","once":true,"onceDelay":0.1,"x":130,"y":120,"wires":[[]]}]

[awaismehmood88]

Hi,
I have same issue code runs 2 3 days then stops without error.

Code

let cronJob = null;
let isRunning = false;
const options = {
    cronTime: `*/5 * * * * *`,
    onTick: fireTick,
    onComplete: () => logger.debug('CRON:TICK job completed'),
    runOnInit: true,
};
cronJob = new CronJob(options);
cronJob.start();

function fireTick() {
    if (isRunning) {
        logger.debug('CRON:TICK Already in execution');
        return true;
    }
    isRunning = true;
    logger.debug('CRON:TICK Finding X job start');
    findJob()
        .then(() => {
            logger.debug('CRON:TICK Finding X job end');
            isRunning = false;
        })
        .catch(e => {
            isRunning = false;
        })
    return true;
}

Logs

{"level":"debug","message":"CRON:TICK Finding X job start","timestamp":"2023-01-21 03:06:10"}
{"level":"debug","message":"CRON:TICK job completed","timestamp":"2023-01-21 03:06:10"}
{"level":"debug","message":"CRON:TICK Finding X job end","timestamp":"2023-01-21 03:06:10"}
{"level":"debug","message":"CRON:TICK Finding X job start","timestamp":"2023-01-21 03:06:15"}
{"level":"debug","message":"CRON:TICK job completed","timestamp":"2023-01-21 03:06:15"}
{"level":"debug","message":"CRON:TICK Finding X job end","timestamp":"2023-01-21 03:06:15"}
{"level":"debug","message":"CRON:TICK Finding X job start","timestamp":"2023-01-21 03:06:20"}
{"level":"debug","message":"CRON:TICK job completed","timestamp":"2023-01-21 03:06:20"}
{"level":"debug","message":"CRON:TICK Finding X job end","timestamp":"2023-01-21 03:06:20"}
{"level":"debug","message":"CRON:TICK job completed","timestamp":"2023-01-21 03:06:39"}
{"level":"debug","message":"CRON:TICK Finding X job start","timestamp":"2023-01-21 03:06:40"}
{"level":"debug","message":"CRON:TICK job completed","timestamp":"2023-01-21 03:06:41"}
{"level":"debug","message":"CRON:TICK Finding X job end","timestamp":"2023-01-21 03:06:44"}

[intcreator]

@awaismehmood88 are you able to reproduce this behavior?

@ChristophDFine what indicates that the error is with Node as opposed to node-cron?

[awaismehmood88]

Yes, unfortunately I had to choose other library over this.

[gramakri]

@awaismehmood88 out of curiosity, which other library did you choose?

[awaismehmood88]

Using node-cron

[intcreator]

@awaismehmood88 I'm trying to reproduce your issue. what does the findJob function do? I use this library for processes that run for months without stopping so it must only happen under specific circumstances