I think that’s a large oversimplification of Facebook. While it’s true a lot of FB storage is MySQL backed they also created many complex systems such as:
- Cassandra (based on dynamo/big table)
- wrote a custom KV store named RocksDb that is open source/now a company
- wrote a custom photos storage system that replaced an NFS based design
- wrote another custom binary object store
- wrote a custom geo distributed graph db (Tao)
- wrote an in house distributed FS replacement for HDFS
https://www.cs.cornell.edu/projects/ladis2009/papers/lakshma...
https://www.usenix.org/legacy/event/osdi10/tech/full_papers/...
https://www.usenix.org/system/files/conference/osdi14/osdi14...
https://www.usenix.org/system/files/conference/atc13/atc13-b...
https://www.cs.princeton.edu/~wlloyd/papers/tectonic-fast21....
https://m.facebook.com/nt/screen/?params=%7B%22note_id%22%3A...