ISSUE
When the restlet script is triggered in quick succession, multiple custom records are created. Only a single custom record is expected to be created per day. But when resltet script is triggered at the same time, custom records are created multiple times.
SOLUTION
This issue can be handled by adding an external Id to the custom record which should be unique for each day. When the restlet is triggered, if the custom record is not created on that day, a custom record will be created and an external id will be set to it. Next time when restlet script is triggered and tried to set the external Id to the custom record, an error will be thrown notifying that the external Id is duplicate and so that another custom record will not be created.