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Subbu Subramaniam

10/02/2020, 8:28 PM
@Elon the realtime consumer automatically adjusts to new tags that may be there in the cluster and removes segments from untagged ones. This is done over time. So, any new consuming segments are allocated ONLY amongst the tagged servers that exist at the time of newly created segment. The old segments (already consumed ones) are left to be retained out (unless you invoke rebalanlce). That said, if you had (say) 4 replicas configured, and only 3 tagged instances exist, then we continue consumption as before on an untagged host sine we don't want to run the risk of losing a replica
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Elon

10/02/2020, 8:42 PM
Thanks, that's good to know! I rebalanced all the tables and then the instances were successfully dropped. Since they didn't exist the rebalance completed quickly.
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Subbu Subramaniam

10/02/2020, 8:54 PM
normally you should not need the rebalance, If the old hosts are not decommissioned, the segemnts ther will just retain out.
Similarly for added capacity, You can just tag new hosts and leave it like that. Over time, new segments will start to be hosted in the new hosts
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Elon

10/02/2020, 8:55 PM
Thanks! I just tag with
Copy code
["DefaultTenant_OFFLINE","DefaultTenant_REALTIME"]
?
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Subbu Subramaniam

10/02/2020, 9:16 PM
multiple tags are always fine, of course
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Ravi Singal

10/05/2020, 8:11 PM
@Subbu Subramaniam question - will the old servers continue to serve the queries?
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Elon

10/05/2020, 8:12 PM
No, they never existed, I think another team that is trying out pinot accidentally added the instances. But just so I know if this ever happens again, what would we have to do if the servers did serve queries?
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Subbu Subramaniam

10/05/2020, 8:13 PM
@Ravi Singal yes
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Ravi Singal

10/05/2020, 8:14 PM
Thanks @Subbu Subramaniam. good to know that.