Distributed Systems — Replication

  1. Real-Time Sync- The replicas have to be in sync with the master. what does in-sync mean? Let's take a Database for example. In most databases, any writes going to the database are generally written to WAL (write-ahead log) first. Assuming the database storage is actually distributed over several storage servers, the data needs to be replicated as well for availability, scalability, and in the case of server crash/failure as a fallback mechanism. But to fallback, as in the server to start serving API requests from the fallback server, it needs to be in sync with the master.
    For eg an application serving hotel bookings to customers. As soon as a write occurs on the portion of the database in the master server, the replicated server needs to be in sync because if the master crashes before the write gets replicated that booking becomes invalid and might get rebooked to someone else.
    So how do we keep replicas in sync near real-time, it is one of the tough problems in computer science to solve out there.

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Data Engineering

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Harry Singh

Harry Singh

Data Engineering

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