My team is using Amazon Kinesis to output the results of queries on other datasets to our own S3 bucket.
Although we were not running the queries often at all, we saw that in our billing console, we were still using 24,000 shard hours so far in December alone.
Does anyone now if Kinesis charges when the shards are actually running, or if they are just up and existing?
You are charged for each shard at an hourly rate. If you enable Extended Data Protection you are charged an additional rate on each shard hour. It does not matter if you are actually using the shard.