We are using H2O (latest version 3.22.1.1) to read parquet data from s3. We use python to talk to H2O. This is single H2O instance - not cluster.
Sometimes we get this error:
Server error water.exceptions.H2OIllegalArgumentException:
  Error: Cannot determine file type. for s3a://BUCKET_NAME/5c2e3fdc0c9c1800019c73f9/part-00001-c33635a2-76dc-4e49-948b-465726b7e3d9-c000.snappy.parquet
File exists and is valid parquet file. Subsequent imports work fine.
This is our python code to import file into H2O
h2o.import_file(path='s3a://BUCKET_NAME/5c2e3fdc0c9c1800019c73f9/part-00001-c33635a2-76dc-4e49-948b-465726b7e3d9-c000.snappy.parquet')
Is there any way to force h2o to use parquet type?
H20 Manual says to do it like df = h2o.import_file("/pathToFile/fileName")  When 
 you need to load data from the machine(s) running H2O to the machine running Python. 
So if your server is not running H20 probably that's why it is showing error.
h2o and parquet - can not determine file type error