Nice! Bash+API = powerful
Good not to flood the service you're grabbing data from TOO much.
Trick is to find the balance between speed and not getting banned.
So you are doing one request every 6 second then?
Could also throw in a randomized wait as well in between requests so it's not just a constant rhythm jackhammer.
I've done that on a few web scraper projects.
Since you are grabbing such a huge data set, if you are interested in speeding things up I would consider splitting it over a few virtual machines on different IP's and share the load.
Depends on your API access though... if it's linked to the one account then no matter. But on the other hand, if it's public data that's anonymous open access for all, split it up into a few cloned VM's
Could get fancy with shared backend MySQL on another server even.
Or just combine the results in the end, via one-way replication, have each VM node a MySQL master and publish back to your central data collector which is a slave to all the bots
http://dev.mysql.com/doc/refman/5.0/en/replication.html
Assuming you have unlimited time and budget to set this all up
