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Type:
Bug
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Resolution: Fixed
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Priority:
Major - P3
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Affects Version/s: None
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Component/s: None
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Labels:None
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Fully Compatible
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ALL
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QO 2021-11-15
This is a test-only bug.
When I run setRandomSeed() with no arguments, the seed it prints appears to be wrong, or not reproducible somehow. When I paste the seed back in I get something deterministic but not the same as the original run with no arguments.
After looking a JSSRand() I think the seed that is printed loses some precision when it's converted from int64_t to a Javascript number (a double).
ubuntu@ip-10-122-11-128:~/mongo$ build/debug/install/bin/mongo --nodb --eval 'Random.setRandomSeed(); print(Random.rand())' MongoDB shell version v5.1.0-alpha-1440-gcab0aa7 setting random seed: 6952011769478614000 0.3131460341608944 ubuntu@ip-10-122-11-128:~/mongo$ build/debug/install/bin/mongo --nodb --eval 'Random.setRandomSeed(6952011769478614000); print(Random.rand())' MongoDB shell version v5.1.0-alpha-1440-gcab0aa7 setting random seed: 6952011769478614000 0.31309103118094894 ubuntu@ip-10-122-11-128:~/mongo$ build/debug/install/bin/mongo --nodb --eval 'Random.setRandomSeed(6952011769478614000); print(Random.rand())' MongoDB shell version v5.1.0-alpha-1440-gcab0aa7 setting random seed: 6952011769478614000 0.31309103118094894