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jainendra tarun

07/01/2021, 7:48 PM
Hello Team, I am observing a few issues - 1) I changed the replicas for a table from 1 to 3. All the segments that are created after the change have 3 replicas, but the pre-existing segments continue to have only 1 replica. 2) When a server node goes down, its hosted segments are not created on another node to maintain 3 replicas for the segments. 3) When I add a new server, no redistribution of segments happen automatically. What are the expectations from Pinot in the above cases?
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Neha Pawar

07/01/2021, 7:52 PM
you have to run a rebalance
for pre existing segments to increase replicas, and also for redistribution of preexisting segments onto the new servers
2 is also not expected to happen automatically. the replication factor is expected to cover for that
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jainendra tarun

07/01/2021, 8:07 PM
@Neha Pawar Thanks for the clarification. Is there any recommendation for the number of replicas in a 10 machine cluster ?
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Neha Pawar

07/01/2021, 8:53 PM
no recommendation as such. Practically i’ve seen production evnironments set it to 3
usually depends on, if you encounter a node failure, then all your query load will go to the remaining replica servers. So can your server handle say 50% more load, or 33% more load, etc