Multiple PHP scripts run at same time in Cron

Question

I have a crontab that looks like the following

* 22 * * * php /var/www/domain1/cron.php
* 22 * * * php /var/www/domain2/cron.php
* 22 * * * php /var/www/domain3/cron.php
* 22 * * * php /var/www/domain4/cron.php
...

However the scrips shown above seems to mess up and run op to a hundred times each! Im not sure why this happens, but since they are all set to start at the same time i would try and change this. It should be said that if i run each cron file manually i see no such behavior and get the expected behavior.

Can i somehow let cron only run one line at a time ? So that when domain1/cron.php is run it will not run domain2/cron.php before domain1/cron.php has finished?

I cannot change the time for them, since i cannot be sure when each one finishes. On one domain it might take 3 seconds while on another it might take 30 minutes.

* 22 means to run the script at 22:00, 22:01, 22:02, 22:03 through 22:59. So each script will be run 60 times. — Barmar
– Barmar, Commented Jul 12, 2016 at 5:41
Turns out that this is my error. Stupid me. Ofcourse it should only run once, which means it should be 0 22 * * * — Daniel Jørgensen
– Daniel Jørgensen, Commented Jul 12, 2016 at 7:38

szenbalu · Accepted Answer · 2016-07-12 10:37:59Z

7

If you have the root permission you can try this way.

* 22 * * * /root/sbin/allDomainsCron.sh

Where allDomainsCron.sh contains your domains cron.php one by one:

#!bin/bash
php /var/www/domain1/cron.php
php /var/www/domain2/cron.php
php /var/www/domain3/cron.php
php /var/www/domain4/cron.php
...

So you can ensure that only one cron.php run at a time.

If you would run the script once a day at 22:00 this code will do the work:

0 22 * * * /root/sbin/allDomainsCron.sh

edited Jul 12, 2016 at 10:37

answered Jul 12, 2016 at 5:47

szenbalu

1931 gold badge4 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Daniel Jørgensen Over a year ago

I've chosen this approach along with fixing my error being that I've not intended to run the script every minute between 22 and 23, but only once.

Barmar Over a year ago

Why does he need root permission? The script doesn't have to be in /root, it can be in his own directory.

szenbalu Over a year ago

You're right, he don't need to have root permission if the script is elsewhere. He need to have root permission when use my example above, when the script is under the /root directory.

Barmar · Accepted Answer · 2016-07-12 05:42:54Z

5

Put them all on a single command line, so they will be run sequentially.

* 22 * * * php /var/www/domain1/cron.php; php /var/www/domain2/cron.php; php /var/www/domain3/cron.php; php /var/www/domain4/cron.php

But since this cron job runs every minute during hour 22, you'll still get overlap if they take more than a minute.

answered Jul 12, 2016 at 5:42

Barmar

789k57 gold badges554 silver badges669 bronze badges

Comments

Sherif · Accepted Answer · 2016-07-12 05:44:31Z

0

No, a crontab does not offer you in-order execution. It's also unreliable to use cron this way. What you're probably wanting instead is an actual queue or job manager that can effectively control the outcome and flow of your desired job execution much more reliably than crontabs can. You could checkout something like RabbitMQ, ZeroMQ, or Gearman for this. Or if you're using AWS, SQS is a good start.

answered Jul 12, 2016 at 5:44

Sherif

12k3 gold badges35 silver badges58 bronze badges

Collectives™ on Stack Overflow

Multiple PHP scripts run at same time in Cron

3 Answers 3

3 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related