Files
scylladb/test/boost
Pavel Emelyanov 54a117b19d Merge 'retry_strategy: Switch to using seastar's retry_strategy (take two)' from Ernest Zaslavsky
With the recent introduction of retry_strategy to Seastar, the pure virtual class previously defined in ScyllaDB is now redundant. This change allows us to streamline our codebase by directly inheriting from Seastar’s implementation, eliminating duplication in ScyllaDB.

Despite this update is purely a refactoring effort and does not introduce functional changes it should be ported back to 2025.3 and 2025.4 otherwise it will make future backports of bugfixes/improvements related to `s3_client` near to impossible

ref: https://github.com/scylladb/seastar/issues/2803

depends on: https://github.com/scylladb/seastar/pull/2960

Closes scylladb/scylladb#25801

* github.com:scylladb/scylladb:
  s3_client: remove unnecessary `co_await` in `make_request`
  s3 cleanup: remove obsolete retry-related classes
  s3_client: remove unused `filler_exception`
  s3_client: fix indentation
  s3_client: simplify chunked download error handling using `make_request`
  s3_client: reformat `make_request` functions for readability
  s3_client: eliminate duplication in `make_request` by using overload
  s3_client: reformat `make_request` function declarations for readability
  s3_client: reorder `make_request` and helper declarations
  s3_client: add `make_request` override with custom retry and error handler
  s3_client: migrate s3_client to Seastar HTTP client
  s3_client: fix crash in `copy_s3_object` due to dangling stream
  s3_client: coroutinize `copy_s3_object` response callback
  aws_error: handle missing `unexpected_status_error` case
  s3_creds: use Seastar HTTP client with retry strategy
  retry_strategy: add exponential backoff to `default_aws_retry_strategy`
  retry_strategy: introduce Seastar-based retry strategy
  retry_strategy: update CMake and configure.py for new strategy
  retry_strategy: rename `default_retry_strategy` to `default_aws_retry_strategy`
  retry_strategy: fix include
  retry_strategy: Copied utils/s3/retry_strategy.hh to utils/s3/default_aws_retry_strategy.hh
  retry_strategy: Copied utils/s3/retry_strategy.cc to utils/s3/default_aws_retry_strategy.cc
2025-10-28 13:08:42 +03:00
..
2025-10-22 14:14:43 +03:00
2025-01-08 09:37:16 +02:00

Scylla unit tests using C++ and the Boost test framework

The source files in this directory are Scylla unit tests written in C++ using the Boost.Test framework. These unit tests come in three flavors:

  1. Some simple tests that check stand-alone C++ functions or classes use Boost's BOOST_AUTO_TEST_CASE.

  2. Some tests require Seastar features, and need to be declared with Seastar's extensions to Boost.Test, namely SEASTAR_TEST_CASE.

  3. Even more elaborate tests require not just a functioning Seastar environment but also a complete (or partial) Scylla environment. Those tests use the do_with_cql_env() or do_with_cql_env_thread() function to set up a mostly-functioning environment behaving like a single-node Scylla, in which the test can run.

While we have many tests of the third flavor, writing new tests of this type should be reserved to white box tests - tests where it is necessary to inspect or control Scylla internals that do not have user-facing APIs such as CQL. In contrast, black-box tests - tests that can be written only using user-facing APIs, should be written in one of newer test frameworks that we offer - such as test/cqlpy or test/alternator (in Python, using the CQL or DynamoDB APIs respectively) or test/cql (using textual CQL commands), or - if more than one Scylla node is needed for a test - using the test/topology* framework.

Running tests

Because these are C++ tests, they need to be compiled before running. To compile a single test executable row_cache_test, use a command like

ninja build/dev/test/boost/row_cache_test

You can also use ninja dev-test to build all C++ tests, or use ninja deb-build to build the C++ tests and also the full Scylla executable (however, note that full Scylla executable isn't needed to run Boost tests).

Replace "dev" by "debug" or "release" in the examples above and below to use the "debug" build mode (which, importantly, compiles the test with ASAN and UBSAN enabling on and helps catch difficult-to-catch use-after-free bugs) or the "release" build mode (optimized for run speed).

To run an entire test file row_cache_test, including all its test functions, use a command like:

build/dev/test/boost/row_cache_test -- -c1 -m1G 

to run a single test function test_reproduce_18045() from the longer test file, use a command like:

build/dev/test/boost/row_cache_test -t test_reproduce_18045 -- -c1 -m1G 

In these command lines, the parameters before the -- are passed to Boost.Test, while the parameters after the -- are passed to the test code, and in particular to Seastar. In this example Seastar is asked to run on one CPU (-c1) and use 1G of memory (-m1G) instead of hogging the entire machine. The Boost.Test option -t test_reproduce_18045 asks it to run just this one test function instead of all the test functions in the executable.

Unfortunately, interrupting a running test with control-C while doesn't work. This is a known bug (#5696). Kill a test with SIGKILL (-9) if you need to kill it while it's running.

Boost tests can also be run using test.py - which is a script that provides a uniform way to run all tests in scylladb.git - C++ tests, Python tests, etc.

Execution with pytest

To run all tests with pytest execute

pytest test/boost

To execute all tests in one file, provide the path to the source filename as a parameter

pytest test/boost/aggregate_fcts_test.cc

Since it's a normal path, autocompletion works in the terminal out of the box.

To execute only one test function, provide the path to the source file and function name

pytest --mode dev test/boost/aggregate_fcts_test.cc::test_aggregate_avg

To provide a specific mode, use the next parameter --mode dev, if parameter isn't provided pytest tries to use ninja mode_list to find out the compiled modes.

Parallel execution is controlled by pytest-xdist and the parameter -n auto. This command starts tests with the number of workers equal to CPU cores. The useful command to discover the tests in the file or directory is

pytest --collect-only -q --mode dev test/boost/aggregate_fcts_test.cc

That will return all test functions in the file. To execute only one function from the test, you can invoke the output from the previous command. However, suffix for mode should be skipped. For example, output shows in the terminal something like this test/boost/aggregate_fcts_test.cc::test_aggregate_avg.dev. So to execute this specific test function, please use the next command

pytest --mode dev test/boost/aggregate_fcts_test.cc::test_aggregate_avg

Writing tests

Because of the large build time and build size of each separate test executable, it is recommended to put test functions into relatively large source files. But not too large - to keep compilation time of a single source file (during development) at reasonable levels.

When adding new source files in test/boost, don't forget to list the new source file in configure.py and also in CMakeLists.txt. The former is needed by our CI, but the latter is preferred by some developers.