Files
scylladb/test/boost
Nadav Har'El fc738ee9ce Merge '[backport 2025.1] token_range_vector: fragment' from Avi Kivity
token_range_vector is a sequence of intervals of tokens. It is used
to describe vnodes or token ranges owned by shards.

Since tokens are bloated (16 bytes instead of 8), and intervals are bloated
(40 byte of overhead instead of 8), and since we have plenty of token ranges,
such vectors can exceed our allocation unit of 128 kB and cause allocation stalls.

This series fixes that by first generalizing some helpers and then changing
token_range_vector to use chunked_vector.

Although this touches IDL, there is no compatibility problem since the encoding
for vector and chunked_vector are identical.

There is no performance concern since token_range_vector is never used on
any hot path (hot paths always contain a partition key).

Fixes #3335.
Fixes #24115.

Fixes #24156

Backport notes:

Due to compiler limitations in this toolchain, the template template parameters were replaced
by elaborate template metaprogramming, see patch 'partition_range_compat: generalize wrap/unwrap helpers'.

Closes scylladb/scylladb#25704

* github.com:scylladb/scylladb:
  dht: fragment token_range_vector
  partition_range_compat: generalize wrap/unwrap helpers
  utils: chunked_vector: add swap() method
  utils: chunked_vector: add range insert() overloads
2025-09-01 19:07:54 +03:00
..
2024-12-23 23:37:02 +01:00
2024-12-22 15:15:23 +02:00
2025-01-08 09:37:16 +02:00
2024-11-06 16:48:36 +02:00
2025-01-09 10:40:39 +00:00

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.

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.