In my website till the last week crons was working fine and suddenly stopped working and even stopped scheduling in the cron_schedule table. so i had truncated cron_schedule and executed php cron.php file through ssh and jobs has been scheduled but this jobs are not executing and status of this jobs are still pending.
Please Help me in debbuging this issue.
It sounds like you have two issues.
For #1, you should check whether someone changed the server configuration that called cron.sh. You want to ensure that some crontab on your system lists a command like this.
*/5 * * * * sh /path/to/your/magento/site/root/cron.sh
You can commonly find cron jobs by running commands like this. Note that you'll need sudo permissions.
echo Display system-wide crontab
sudo cat /etc/crontab
echo Display crontabs for all users on system
for user in $(cut -f1 -d: /etc/passwd); do echo $user; sudo crontab -u $user -l; done
More details available in this post.
How to configure Magento cron job
To schedule, configure and to now status of cron you can use cron scheduler module.
you can try this module --
There is a possibility that a cron process has got stuck
If you have shell access
ps aux | grep php
Locate process id next to cron.php
kill -9 123456 where 123456 is the process I'd
Once the stuck process is terminated the schedule should refresh and resume
bin/sh /mahentoroot/cron.shvia ssh and see what error is coming