How JunoDB is designed to achieve six 9's of availability

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In this video, I delved into JunoDB's data redundancy for achieving high availability in a payments platform like PayPal. Explained the importance of redundancy in ensuring system resilience against outages. Discussed JunoDB's elegant grid-based storage layout for data replication across multiple zones. Detailed the process of synchronous replication within a data center and asynchronous replication between data centers for disaster recovery. Highlighted the critical role of redundancy in maintaining uninterrupted service for financial transactions. It's crucial for engineers to grasp these concepts for designing robust distributed data stores.
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[@pollathajeeva23]

Hi Arpit, Juno DB mentioned that the "quorum-based protocol to sync replicas and uses etcd" which means it uses Raft for consensus?

[@rajivsarkar277]

i have a doubt here .what is mapping that juno proxy maintains is it shard to storage server or shard to storage group

[@UtkarshRathore]

Async replication across different data centers can result in inconsistent data if site A goes down before data can be replicated to site B, right?

[@the10xdev]

Might be async, but it’s not fire and forget. I guess it would track the keys it wasn’t able to replicate ( followers down etc.. ), it’ll track it and send it to follower when it comes back up.

[@varundey9790]

I had the same question. @@the10xdev reads from site B could still be missed in this case since data was written to A but could not be replicated to B. Now A is down and the reads are happening from B. Assuming this is the case of running in degraded mode.

[@UtkarshRathore]

@@the10xdev Yes, my point is until site A is back up (which can run into hours) and the reconciliation process for unreplicated data is complete, any reads from site B can potentially return inconsistent data. This may be acceptable for some systems but not for a payment system.

[@venkatsh6r]

@@UtkarshRathore In the event of network partition (failure), a system can achieve either consistency or availability, but not both.