BigchainDB relies heavily on a global notification system to be able to react every time there is a change in the database
How We Integrated With MongoDB
Rodolphe Marques

How do database-holding nodes notify the data changes to their neighbor or elsewhere? It would be nice to share the topology and casting scheme you’re building on. How is your system different than existing distributed hash table (DHT) schemes being used since the early 2000s?