Files saved to the MerusCase system are immediately backed up in multiple data centers across several time zones. “Immediately” in this context is typically less than 500 milliseconds, but may take up to a few minutes with large files.
MerusCase uses the Amazon Simple Storage Service to facilitate this level of real time data redundancy. According to Amazon: “Amazon S3 is designed to provide 99.999999999% durability of objects over a given year. This durability level corresponds to an average annual expected loss of 0.000000001% of objects. For example, if you store 10,000 objects with Amazon S3, you can on average expect to incur a loss of a single object once every 10,000,000 years. In addition, Amazon S3 is designed to sustain the concurrent loss of data in two facilities.” (Retrieved from Amazon in April 2014.)
Database-driven transactions, i.e., non-file based data saved to MerusCase application directly in a browser, may take up to several minutes to propagate across redundant data storage facilities. A “snapshot” archive of the production database is created daily.
In the event of a zombie apocalypse, MerusCase engineering might have to revert to a snapshot archive from the night before and restore the dataset to a new data center that hasn’t been overrun by the walking dead. For your typical act of god, however, no data ever saved to MerusCase is ever in danger of being lost under any circumstances.