Most elegant way to execute a AWS lambda function with preloaded parameters on a specific time

Question

I am looking for the following workflow:

• Add an entry to a table of my Postgres database with a end_date and state (with the following values: active or done) columns.
• Execute a lambda at the exact end_date value to update the state of this specific entry from active to done

The only ressources I found on Google about how scheduling a lambda function was for repetitive execution but I'm looking for single execution at specific date and time.

Any suggestions?

• JeffO: Can you share what you found on Google? It may improve the answer to show how to make a minor change instead of creating a whole new example?
• Dan Pichelman: How many entries in the database are we talking about? The right answer for 20 records won't be the right answer for 20,000 or 20 million.
• Dan Pichelman: Also, how 'exact' do you need to be? Within a couple of hours? a couple of minutes? no more than 10 milliseconds from the end_date?
• Jean Lbr: @JeffO Here is what I found: alestic.com/2015/05/aws-lambda-recurring-schedule Clearly after few more readings, I think the correct approach is to execute a lambda recurrently and check if I need to switch the status from active to done on all the rows of the table that are marked as active
• Jean Lbr: @DanPichelman We're talking about few hundreds (maybe few thousands in a couple of months) entries in the table and the exactitude span should be between minutes and hours.

Answer 1

You can schedule a lambda function to run as a crontab entry, and in the crontab entry set the exact date/time with no repetition.

• JeffO: How does this execute on the exact end date? Assuming there's more than one unique value across all records.