Commit Graph

4 Commits

Author SHA1 Message Date
Nadav Har'El
c298088375 alternator test: use ConsistentRead=True for full_query/scan
Many of the Alternator tests use the convenience functions full_query()/
full_scan() to read from the table. Almost all these tests need to be able
to read their own writes, i.e., want ConsistentRead=True, but none of them
explicitly specified this parameter. Such tests may sporadically fail when
running on cluster with multiple nodes.

So this patch follows a TODO in the code, and makes ConsistentRead=True
the default for the full_*() functions. The caller can still override it
with ConsistentRead=False - and this is necessary in the GSI tests, because
ConsistentRead=True is not allowed in GSIs.

Note that while ConsistentRead=True is now the default for the full_*()
convenience functions, but it is still not the default for the lower level
boto3 functions scan(), query() and get_item() - so usages of those should
be evaluated as well and missing ConsistentRead=True, if any, should be
added.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200616073821.824784-1-nyh@scylladb.com>
2020-06-17 14:57:45 +02:00
Nadav Har'El
0d337a716b alternator test: confirm understanding of query paging with filtering
This test (which passes successfully on both Alternator and DynamoDB)
was written to confirm our understanding of how the *paging* feature
works.

Our understanding, based on DynamoDB documentation, has been that the
"Limit" parameter determines the number of pre-filtering items, *not*
the actual number of items returned after having passed the filter.
So the number of items actually returned may be lower than Limit - in
some cases even zero.

This test tries an extreme case: We scan a collection of 20 items with
a filter matching only 10 (or so) of them, with Limit=1, and count
the number of pages that we needed to request until collecting all these
10 (or so) matches. We note that the result is 21 - i.e., DynamoDB and
Alternator really went through the 20 pre-filtering items one by one,
and for the items which didn't match the filter returned an empty page.
The last page (the 21st) is always empty: DynamoDB or Alternator doesn't
know whether or not there is a 21st item, and it takes a 21st request
to discover there isn't.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200602145015.361694-1-nyh@scylladb.com>
2020-06-02 16:57:49 +02:00
Nadav Har'El
43138c0e5e alternator test: test Count/ScannedCount return of Query
This test reproduces a bug in the current implementation of
QueryFilter, which returns for ScannedCount the count of
post-filter items, whereas it should return the pre-filter
count.

The test tests both ScannedCount and Count, when QueryFilter
is used and when it isn't used.

The test currently xfails on Alternator, passes on DynamoDB.

Refs #5028

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200602125924.358636-1-nyh@scylladb.com>
2020-06-02 16:57:49 +02:00
Nadav Har'El
4e2bf28b84 alternator-test: make Alternator tests runnable from test.py
To make the tests in alternator-test runnable by test.py, we need to
move the directory alternator-test/ to test/alternator, because test.py
only looks for tests in subdirectories of test/. Then, we need to create
a test/alternator/suite.yaml saying that this test directory is of type
"Run", i.e., it has a single run script "run" which runs all its tests.

The "run" script had to be slightly modified to be aware of its new
location relative to the source directory.

To run the Alternator tests from test.py, do:

	./test.py --mode dev alternator

Note that in this version, the "--mode" has no effect - test/alternator/run
always runs the latest compiled Scylla, regardless of the chosen mode.

The Alternator tests can still be run manually and individually against
a running Scylla or DynamoDB as before - just go to the test/alternator
directory (instead of alternator-test previously) and run "pytest" with
the desired parameters.

Fixes #6046

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2020-04-12 16:27:45 +03:00