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Type:
Bug
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Resolution: Done
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Priority:
Major - P3
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Affects Version/s: 3.0
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Component/s: None
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Labels:None
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Environment:pymongo==3.0.1-2-81549e
This is a really strange one...
When connecting through a mongos, I'm seeing an issue where find_one with PRIMARY_PREFERRED doesn't return any output.
c = ...some_collection ...
c.with_options(read_preference=ReadPreference.PRIMARY_PREFERRED)
c.find_one({'symbol': symbol}, sort=[('version', pymongo.DESCENDING)])
returns None. Whereas:
c.find_one({'symbol': symbol})
return an item.
len(list(c.find({'symbol': symbol}))
Out[76]: 25
In [79]: [x for x in list(c.find({'symbol': symbol})) if x is None]
Out[79]: []
Note a normal find finds nothing too.
In [84]: c = lib._versions.with_options(read_preference=ReadPreference.PRIMARY_PREFERRED)
In [85]: len(list(c.find({'symbol': symbol}, sort=[('version', pymongo.DESCENDING)])))
Out[85]: 0
If I change the read-preference, it works!
In [82]: c = lib._versions.with_options(read_preference=ReadPreference.PRIMARY)
In [83]: len(list(c.find({'symbol': symbol}, sort=[('version', pymongo.DESCENDING)])))
Out[83]: 25
- is duplicated by
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- Closed
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