Cannot access the query profile or error logs if it fails.

[ishaan]

Use Case:

Run a query through impyla, and the query fails. I want to get some additional information, namely:
- The error log (via cursor.get_log())
- The query profile (via cursor.get_profile())

Problem:
I get the following error:

In [17]: cursor.get_log()

AttributeError Traceback (most recent call last)
in ()
----> 1 cursor.get_log()

/home/ishaan/cmf/systest/target/env/src/impyla/impala/hiveserver2.pyc in get_log(self)
396
397 def get_log(self):
--> 398 return self._last_operation.get_log()
399
400 def get_profile(self):

AttributeError: 'NoneType' object has no attribute 'get_log'

Both of these methods internally call last_operation.get{log, profile}()
However, when a query fails, _last_operation is set to None (which is should not be).

[julienbaley]

@wesm can we get some help on this issue? This problem still exists in 0.13.7, except the _last_operation is not None anymore. When calling .get_log() on the cursor after a failed query, thriftpy sends thriftpy.thrift.TApplicationException: Invalid method name: 'GetLog'

This is a problem for us as we let user write their own SQL and we'd like to let them know what went wrong with their query..