To remove the dependency on Python 2, existing scripts need to use
python3 rather than python. These commands find those
locations (for impala-python and regular python):
git grep impala-python | grep -v impala-python3 | grep -v impala-python-common | grep -v init-impala-python
git grep bin/python | grep -v python3
This removes or switches most of these locations by various means:
1. If a python file has a #!/bin/env impala-python (or python) but
doesn't have a main function, it removes the hash-bang and makes
sure that the file is not executable.
2. Most scripts can simply switch from impala-python to impala-python3
(or python to python3) with minimal changes.
3. The cm-api pypi package (which doesn't support Python 3) has been
replaced by the cm-client pypi package and interfaces have changed.
Rather than migrating the code (which hasn't been used in years), this
deletes the old code and stops installing cm-api into the virtualenv.
The code can be restored and revamped if there is any interest in
interacting with CM clusters.
4. This switches tests/comparison over to impala-python3, but this code has
bit-rotted. Some pieces can be run manually, but it can't be fully
verified with Python 3. It shouldn't hold back the migration on its own.
5. This also replaces locations of impala-python in comments / documentation /
READMEs.
6. kazoo (used for interacting with HBase) needed to be upgraded to a
version that supports Python 3. The newest version of kazoo requires
upgrades of other component versions, so this uses kazoo 2.8.0 to avoid
needing other upgrades.
The two remaining uses of impala-python are:
- bin/cmake_aux/create_virtualenv.sh
- bin/impala-env-versioned-python
These will be removed separately when we drop Python 2 support
completely. In particular, these are useful for testing impala-shell
with Python 2 until we stop supporting Python 2 for impala-shell.
The docker-based tests still use /usr/bin/python, but this can
be switched over independently (and doesn't impact impala-python)
Testing:
- Ran core job
- Ran build + dataload on Centos 7, Redhat 8
- Manual testing of individual scripts (except some bitrotted areas like the
random query generator)
Change-Id: If209b761290bc7e7c716c312ea757da3e3bca6dc
Reviewed-on: http://gerrit.cloudera.org:8080/23468
Reviewed-by: Michael Smith <michael.smith@cloudera.com>
Tested-by: Michael Smith <michael.smith@cloudera.com>
This puts all of the thrift-generated python code into the
impala_thrift_gen package. This is similar to what Impyla
does for its thrift-generated python code, except that it
uses the impala_thrift_gen package rather than impala._thrift_gen.
This is a preparatory patch for fixing the absolute import
issues.
This patches all of the thrift files to add the python namespace.
This has code to apply the patching to the thirdparty thrift
files (hive_metastore.thrift, fb303.thrift) to do the same.
Putting all the generated python into a package makes it easier
to understand where the imports are getting code. When the
subsequent change rearranges the shell code, the thrift generated
code can stay in a separate directory.
This uses isort to sort the imports for the affected Python files
with the provided .isort.cfg file. This also adds an impala-isort
shell script to make it easy to run.
Testing:
- Ran a core job
Change-Id: Ie2927f22c7257aa38a78084efe5bd76d566493c0
Reviewed-on: http://gerrit.cloudera.org:8080/20169
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Reviewed-by: Riza Suminto <riza.suminto@cloudera.com>
This takes steps to make Python 2 behave like Python 3 as
a way to flush out issues with running on Python 3. Specifically,
it handles two main differences:
1. Python 3 requires absolute imports within packages. This
can be emulated via "from __future__ import absolute_import"
2. Python 3 changed division to "true" division that doesn't
round to an integer. This can be emulated via
"from __future__ import division"
This changes all Python files to add imports for absolute_import
and division. For completeness, this also includes print_function in the
import.
I scrutinized each old-division location and converted some locations
to use the integer division '//' operator if it needed an integer
result (e.g. for indices, counts of records, etc). Some code was also using
relative imports and needed to be adjusted to handle absolute_import.
This fixes all Pylint warnings about no-absolute-import and old-division,
and these warnings are now banned.
Testing:
- Ran core tests
Change-Id: Idb0fcbd11f3e8791f5951c4944be44fb580e576b
Reviewed-on: http://gerrit.cloudera.org:8080/19588
Reviewed-by: Joe McDonnell <joemcdonnell@cloudera.com>
Tested-by: Joe McDonnell <joemcdonnell@cloudera.com>
Python 3 now treats print as a function and requires
the parenthesis in invocation.
print "Hello World!"
is now:
print("Hello World!")
This fixes all locations to use the function
invocation. This is more complicated when the output
is being redirected to a file or when avoiding the
usual newline.
print >> sys.stderr , "Hello World!"
is now:
print("Hello World!", file=sys.stderr)
To support this properly and guarantee equivalent behavior
between python 2 and python 3, all files that use print
now add this import:
from __future__ import print_function
This also fixes random flake8 issues that intersect with
the changes.
Testing:
- check-python-syntax.sh shows no errors related to print
Change-Id: Ib634958369ad777a41e72d80c8053b74384ac351
Reviewed-on: http://gerrit.cloudera.org:8080/19552
Reviewed-by: Joe McDonnell <joemcdonnell@cloudera.com>
Reviewed-by: Michael Smith <michael.smith@cloudera.com>
Tested-by: Michael Smith <michael.smith@cloudera.com>
Minor compactions can compact several delta directories into a single
delta directory. The current directory filtering algorithm had to be
modified to handle minor compacted directories and prefer those over
plain delta directories. This happens in the Frontend, mostly in
AcidUtils.java.
Hive Streaming Ingestion writes similar delta directories, but they
might contain rows Impala cannot see based on its valid write id list.
E.g. we can have the following delta directory:
full_acid/delta_0000001_0000010/0000 # minWriteId: 1
# maxWriteId: 10
This delta dir contains rows with write ids between 1 and 10. But maybe
we are only allowed to see write ids less than 5. Therefore we need to
check the ACID write id column (named originalTransaction) to determine
which rows are valid.
Delta directories written by Hive Streaming don't have a visibility txn
id, so we can recognize them based on the directory name. If there's
a visibilityTxnId and it is committed => every row is valid:
full_acid/delta_0000001_0000010_v01234 # has visibilityTxnId
# every row is valid
If there's no visibilityTxnId then it was created via Hive Streaming,
therefore we need to validate rows. Fortunately Hive Streaming writes
rows with different write ids into different ORC stripes, therefore we
don't need to validate the write id per row. If we had statistics,
we could validate per stripe, but since Hive Streaming doesn't write
statistics we validate the write id per ORC row batch (an alternative
could be to do a 2-pass read, first we'd read a single value from each
stripe's 'currentTransaction' field, then we'd read the stripe if the
write id is valid).
Testing
* the frontend logic is tested in AcidUtilsTest
* the backend row validation is tested in test_acid_row_validation
Change-Id: I5ed74585a2d73ebbcee763b0545be4412926299d
Reviewed-on: http://gerrit.cloudera.org:8080/15818
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
