Details
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Improvement
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Resolution: Won't Fix
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Minor
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None
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Mad Hatter
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1
Description
First I understand that vBuckets != 1024 is not supported (but we do have 64 vBuckets for macOS).
When exploring Eventing performance characteristics on a non-MDS one node server ( e.g. why is it slow on a single Linux node) at various vBuckets settings 1024, 512, 256, 128 and 64 - these all worked.
SELECT count(*) cnt, type from `travel-sample` group by type
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1968 airport
917 hotel
4495 landmark
24024 route
187 airline
I then tried 340 (which is not a factor of 1024) to emulate a 3 node KV system my eventing test worked as expected BUT queries did not.
1024/340 = 3.0117
We get wrong answers via N1QL if COUCHBASE_NUM_VBUCKETS is set to a non factor of 1024:
export COUCHBASE_NUM_VBUCKETS=340
install couchbase and setup then load `travel-sample` run these two queries
SELECT count(*) cnt from `travel-sample`
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cnt
31591
SELECT count(*) cnt, type from `travel-sample` group by type
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|
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4 airline
18 airport
8 hotel
56 landmark
312 route
SELECT count(*) cnt from `travel-sample` where type = 'hotel'
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cnt
917