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One of the advantages of ElasticSearch is that it's easily scalable, we can replicate it easily in



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communities we deploy replicated database applications, always using stateful set component.



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Why?



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Because Stateful Said has an additional mechanism that helps manage the replicas in the cluster database.



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For example, it gives a master database and the slave databases their own sticky identities, so each



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replica knows its role even after it dies and gets recreated.



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It also supports directly addressing the master for right requests using a service name.



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And this is important because Master is the only one allowed to write to the data so that no data inconsistency



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happens.



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Stateful said also supports reattaching the right storage to the restarted pod when he dies, because



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instead of all applications, as the name suggests, each pod will have a state and when it restarts,



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it will need the old state to continue from where it left off.



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And since the state is stored in the volume with external storage, it's important that the same storage



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with the previous state gets reattached to the same pod when it dies and gets recreated so that it can



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load its previous state and continue where it left off.



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In comparison, deployment doesn't care about all this stuff.



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It manages and replicate stateless applications.



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So when parts of such application restart, they always start from a fresh new state.



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Also, there is no master or slave in the set up.



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Each pod replica of stateless application is identical, so there's no complexity of replicating these



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kind of applications.



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And that's the difference between deployment and stateful, said component's.