Bankim Bhavsar has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/14745 )

Change subject: Import Impala's blocked based BloomFilter
......................................................................


Patch Set 4:

> Patch Set 4: Verified-1
>
> Build Failed
>
> http://jenkins.kudu.apache.org/job/kudu-gerrit/19688/ : FAILURE

> /home/jenkins-slave/workspace/kudu-master/1/src/kudu/util/block_bloom_filter-test.cc:179
> Expected: (found) <= (find_limit * expected_fpp * 8), actual: 51 vs 48.0793
> Too many false positives with -log2(fpp) = 11

Looks like change to use SeedRandom() that uses current time instead of earlier 
fixed seed srand(0) is exposing some issue in the false-positive rate observed.

I took a peek why the expected range of fpp is 1x >= expected fpp <= 8x but 
couldn't find a good reason looking at Impala git history.

Investigating further...


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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I89c54a051c5093cf5fb81481a47a0a6677d7d906
Gerrit-Change-Number: 14745
Gerrit-PatchSet: 4
Gerrit-Owner: Bankim Bhavsar <[email protected]>
Gerrit-Reviewer: Adar Dembo <[email protected]>
Gerrit-Reviewer: Alexey Serbin <[email protected]>
Gerrit-Reviewer: Andrew Wong <[email protected]>
Gerrit-Reviewer: Bankim Bhavsar <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Thomas Tauber-Marshall <[email protected]>
Gerrit-Reviewer: Tidy Bot (241)
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Todd Lipcon <[email protected]>
Gerrit-Comment-Date: Tue, 26 Nov 2019 19:19:27 +0000
Gerrit-HasComments: No

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