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https://issues.apache.org/jira/browse/ARROW-15645?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17490156#comment-17490156
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Ravi Gummadi commented on ARROW-15645:
--------------------------------------

The issue is seen only with pyarrow 5.0.0 and is not seen with pyarrow 3.0.0.
_________________________
Some investigation details from my side while debugging validate():

The offsets are having opposite byte-order with pyarrow 5.0.0 (from validate.cc)

(gdb) p data.buffers[1]->data()
$8 = (const uint8_t *) 0x3fff9680040 ""
(gdb) p data.buffers[1]->data()[4]
$9 = 26 '\032'

The same flight server is used for reading data. When I run the above sample 
code with pyarrow 3.0.0, I see the following correct offset values with the 
right byte-order.
>From data.h GetValues() called from validate.cc:

(gdb) p buffers[1]->data()
$11 = (const uint8_t *) 0x2aa00a544b2 ""
(gdb) p buffers[1]->data()[4]
$12 = 0 '\000'
(gdb) p buffers[1]->data()[5]
$13 = 0 '\000'
(gdb) p buffers[1]->data()[6]
$14 = 0 '\000'
(gdb) p buffers[1]->data()[7]
$15 = 26 '\032'

> Data read through Flight is having endianness issue on s390x
> ------------------------------------------------------------
>
>                 Key: ARROW-15645
>                 URL: https://issues.apache.org/jira/browse/ARROW-15645
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: C++, FlightRPC, Python
>    Affects Versions: 5.0.0
>         Environment: Linux s390x (big endian)
>            Reporter: Ravi Gummadi
>            Priority: Major
>
> Am facing an endianness issue on s390x(big endian) when converting the data 
> read through flight to pandas data frame.
> (1) table.validate() fails with error
> Traceback (most recent call last):
>   File "/tmp/2.py", line 51, in <module>
>     table.validate()
>   File "pyarrow/table.pxi", line 1232, in pyarrow.lib.Table.validate
>   File "pyarrow/error.pxi", line 99, in pyarrow.lib.check_status
> pyarrow.lib.ArrowInvalid: Column 1: In chunk 0: Invalid: Negative offsets in 
> binary array
> (2) table.to_pandas() gives a segmentation fault
> ____________
> Here is a sample code that I am using:
> from pyarrow import flight
> import os
> import json
> flight_endpoint = os.environ.get("flight_server_url", 
> "grpc+tls://...local:443")
> print(flight_endpoint)
> #
> class TokenClientAuthHandler(flight.ClientAuthHandler):
>     """An example implementation of authentication via handshake.
>        With the default constructor, the user token is read from the 
> environment: TokenClientAuthHandler().
>        You can also pass a user token as parameter to the constructor, 
> TokenClientAuthHandler(yourtoken).
>     """
>     def {_}__{_}init{_}__{_}(self, token: str = None):
>         super().{_}__{_}init{_}__{_}()
>         if( token != None):
>             strToken = strToken = 'Bearer {}'.format(token)
>         else:
>             strToken = 'Bearer {}'.format(os.environ.get("some_auth_token"))
>         self.token = strToken.encode('utf-8')
>         #print(self.token)
>     def authenticate(self, outgoing, incoming):
>         outgoing.write(self.token)
>         self.token = incoming.read()
>     def get_token(self):
>         return self.token
>     
> readClient = flight.FlightClient(flight_endpoint)
> readClient.authenticate(TokenClientAuthHandler())
> cmd = json.dumps(\{...})
> descriptor = flight.FlightDescriptor.for_command(cmd)
> flightInfo = readClient.get_flight_info(descriptor)
> reader = readClient.do_get(flightInfo.endpoints[0].ticket)
> table = reader.read_all()
> print(table)
> print(table.num_columns)
> print(table.num_rows)
> table.validate()
> table.to_pandas()



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