Data recovery in multi-leader distributed systems

A method comprising:

• determining whether a first data storage unit of a first computer system in a distributed system has failed, wherein the first computer system is one of a plurality of computer systems in the distributed system and wherein each of the computer systems includes at least a read-write computer and a data storage unit;
• responsive to a determination that the first data storage unit has failed, determining if the data from the first data storage unit is replicated to other computer systems in the distributed system that have subscribed to the data from the first computer system;
• responsive to a determination that the data from the first data storage unit is not replicated to the other computer systems, determining a particular data storage unit in the distributed system that has latest data corresponding to the first data storage unit;
• and
• replicating, via a publish-subscribe model, the latest data from the particular data storage unit to the other computer systems.

An apparatus comprising:

• a distributed system having a plurality of computer systems, each of the computer systems having at least
• a read-write computer to serve a read request and/or a write request from a client,
• a data storage unit to store data forwarded from the read-write computer, and
• a replication module to replicate, via a publish-subscribe model, the data stored in the data storage unit of a computer system to data storage units of other computer systems, wherein the other computer systems are computer systems that have subscribed to data from the data storage unit and wherein the replication module transmits the data from the data storage unit to read-write computers of the other computer systems.