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@gortiz gortiz commented Apr 17, 2023

The description that explains the case when replica is 1 wasn't very clear. Specifically, when increasing the number of replicas.

This PR adds a couple of paragraphs to specifically focus on the replica 1 case.

| bootstrap | false | Rebalances all segments again, **as if adding segments to an empty table**. If this is false, then the rebalance will try to minimize segment movements. |

### Rebalance with only 1 replica
In general, when the table config uses only 1 replica, the downtime may be affected.
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@swaminathanmanish swaminathanmanish Apr 17, 2023

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Just a minor reword if it makes sense.

"The downtime option is not relevant when rebalance is initiated on a table with a replication factor of 1 and there's no further change to the replication factor. In this case, there'll be a downtime during rebalance.

However when the rebalance is initiated for increasing replication (from 1 to > 1), the downtime flag can be used (set to false) to avoid downtime."

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i think with downtime = false and replication = 1 (with no changes to final replication count), the rebalance will itself be blocked. So this would be untrue "In this case, there'll be a downtime during rebalance"

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What do you mean with the rebalance itself will be blocked?

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I've recently found this PR is still open. I'm going to apply the change suggested by Manish. About the suggestion from Neha... do we know the actual behavior? IIRC I didn't actually tested that and the written here is what I inferred seen the code, but I may be wrong.

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@npawar, is this one good to merge re @gortiz comment above?

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4 participants