The “leap second bug” hit just as the web was recovering from a major outage to Amazon Web Services, an online operation that runs as much as one percent of the internet. Some operations, including Google, saw the leap second coming and prepared for it, but others weren’t so diligent.
In a post to Twitter, Reddit — the popular news aggregation and discussion site owned by the same parent company as Wired — said it was experiencing problems with “Java/Cassandra,” referring to the open source database, and it attributed these problems to the leap second. Originally designed by Facebook and now used across the web and beyond, Cassandra is built with Java.