I am dealing with a workflow where I need to start three processes. I have the first process which is to be scheduled at the beginning of every hour and the rest two at 45th minute of every hour and the 52nd minute of every hour.
But Instead of making the client schedule two different jobs on their server what I would rather want is to have just one job configured to run in the beginning of every hour which does a bunch of stuff and then starts these cron jobs at their respective times. i.e. 45th minute and 52nd minute of the hour.
Is there any way to do this.
I don't have any experience with shell scripting and always schedule cron jobs manually on cron-tab.
Thanks!
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Is it possible to execute a Cron job such that between certain hours, it executes every 30 minutes, but other hours, only every 1 hour?
I was unable to figure this out using my basic Cron abilities.
I have a cron job that runs every 30 minutes, starting 10 minutes past a whole hour:
0+10/30+*+*+*+?
Now, this needs to be changed, so that in a specific time interval, it runs every 15 minutes instead. E.g. at 7.50, 8.05, 8.20 and 8.35. Then every 30 minutes again.
Is this possible with a single cron job and if so, how? Or do I need multiple jobs to accomplish this?
Thank you in advance.
not easy in a single cron, and that is also hard to read.
multiple jobs may work fine and show much clear
// This will start at 1:10am, and every 30minutes run once.
0+10/30+1-23/2+*+*+?
// This will start at 0:10am, and every 15minutes run once.
0+10/15+0-24/2+*+*+?
you may also consider to void the two job running at the same time.
As far as I've understood, this is not possible within a single cron job.
setup cron from morning to evening only points out that three different cron jobs are needed, so I am closing my question.
I have to perform 2 jobs - A and B. Job 'A' is to be prformed at 9:00 am of every weekday. I dont know the duration for job 'A' though, duration may vary.
Also I want to perform job 'B' after 3mins of completion of job 'A'.
Can anyone suggest the cron expression for this please.
Assuming you are trying to run the second job three minutes after the first job completes, let's say you have Job A which involves calling /home/user/job_a.sh and then once that completes, you want to run /home/user/job_b.sh. Instead of trying to set up two different Cron jobs, you could just make a separate script, say job_c.sh. And all job_c.sh does is run Job A, wait three minutes and then run Job B.
Basically, rather than calling two Cron Jobs and trying to sort out timing for both of them, you can just establish one Cron Job which runs both jobs.
On the other hand, if you want to run the second job three minutes after the first one starts then you might as well create two Cron Jobs with three minutes between them which would look something like this:
00 9 * * 1-5 /home/user/job_a.sh
03 9 * * 1-5 /home/user/job_b.sh
I have scheduled the K8s cron to run every 30 mins.
If the current job is still running and the next cron schedule has reached it shouldn't create a new job but rather wait for the next schedule.
And repeat the same process if the previous job is still in Running state.
set the following property to Forbid in CronJob yaml
.spec.concurrencyPolicy
https://kubernetes.io/docs/tasks/job/automated-tasks-with-cron-jobs/#concurrency-policy
spec.concurrencyPolicy: Forbid will hold off starting a second job if there is still an old one running. However that job will be queued to start immediately after the old job finishes.
To skip running a new job entirely and instead wait until the next scheduled time, set .spec.startingDeadlineSeconds to be smaller than the cronjob interval (but larger than the max expected startup time of the job).
If you're running a job every 30 minutes and know the job will never take more than one minute to start, set .spec.startingDeadlineSeconds: 60
I have written a shell script for data extraction that accepts two parameters - Start time and end time in YYDDMMHHSSSS format. The shell script in turn will run sql queries and fetch data between these two date parameters.
My intention is to deploy the shell script as a cron job which should run at least once every day(preferably every 6 hours). The second time it runs it should use that last End time as the Start time, and the new End time as, say (Starttime + 6 hours). So all data is always extracted once. Another job will kick off at say 12 in the midnight everyday and it will pick up the data that the shell scrip deposited for that day.
I have never setup a cron job before but it looks doable from what I have read, I'm not sure if the above thing can be done though?
Cron executes jobs at specific times and/or days with all parameters for the script defined at the time the job is placed into the cron job table. The script needs to handle all other requirements. If your requirements are based on the current time and the last time the script was executed, then the script will need to preserve the time of execution each time it is run and the obtain the last time it was invoked from the information preserved.
In this particular case, because you are accessing a database, I suggest that you use the database to preserve time of the previous script execution.