200bc82913
In commit acfa180766 we added to
test/cql-pytest a mechanism to detect when Scylla crashes in the middle
of a test function - in which case we report the culprit test and exit
immediately to avoid having a hundred more tests report that they failed
as well just because Scylla was down.
However, if Scylla was *never* up - e.g., if the user ran "pytest" without
ever running Scylla - we still report hundreds of tests as having failed,
which is confusing and not helpful.
So with this patch, if a connection cannot be made to Scylla at all,
the test exits immediately, explaining what went wrong, not blaming
any specific test:
$ pytest
...
! _pytest.outcomes.Exit: Cannot connect to Scylla at --host=localhost --port=9042 !
============================ no tests ran in 0.55s =============================
Beyond being a helpful reminder for a developer who runs "pytest" without
having started Scylla first (or using test/cql-pytest/run or test.py to
start Scylla easily), this patch is also important when running tests
through test.py if it reuses an instance of Scylla that crashed during an
earlier pytest file's run.
This patch does not fix test.py - it can still try to run pytest with
a dead Scylla server without checking. But at least with this patch
pytest will notice this problem immediately and won't report hundreds of
test functions having failed. The only report the user will see will be
the last test which crashed Scylla, which will make it easier to find
this failure without being hidden between hundreds of spurious failures.
Fixes #12360
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes #12401
Single-node functional tests for Scylla's CQL features.
These tests use the Python CQL library and the pytest frameworks. By using an actual CQL library for the tests, they can be run against any implementation of CQL - both Scylla and Cassandra. Most tests - except in rare cases - should pass on both, to ensure that Scylla is compatible with Cassandra in most features.
To run all tests against an already-running local installation of Scylla
or Cassandra on localhost, just run pytest. The "--host" and "--port"
can be used to give a different location for the running Scylla or Cassanra.
The "--ssl" option can be used to use an encrypted (TLSv1.2) connection.
More conveniently, we have two scripts - "run" and "run-cassandra" - which do all the work necessary to start Scylla or Cassandra (respectively), and run the tests on them. The Scylla or Cassandra process is run in a temporary directory which is automatically deleted when the test ends.
"run" automatically picks the most recently compiled version of Scylla in
build/*/scylla - but this choice of Scylla executable can be overridden with
the SCYLLA environment variable. "run-cassandra" defaults to running the
command cassandra from the user's path, but this can be overriden by setting
the CASSANDRA environment variable to the path of the cassandra script,
e.g., export CASSANDRA=$HOME/apache-cassandra-3.11.10/bin/cassandra.
A few of the tests also require the nodetool when running on Cassandra -
this tool is again expected to be in the user's path, or be overridden with
the NODETOOL environment variable. Nodetool is not needed to test
Scylla.
Additional options can be passed to "pytest" or to "run" / "run-cassandra" to control which tests to run:
- To run all tests in a single file, do
pytest test_table.py. - To run a single specific test, do
pytest test_table.py::test_create_table_unsupported_names. - To run the same test or tests 100 times, add the
--count=100option. This is faster than runningrun100 times, because Scylla is only run once, and also counts for you how many of the runs failed. Forpytestto support the--countoption, you need to install a pytest extension:pip install pytest-repeat
Additional useful pytest options, especially useful for debugging tests:
- -v: show the names of each individual test running instead of just dots.
- -s: show the full output of running tests (by default, pytest captures the test's output and only displays it if a test fails)