fc64333040
This is yet another part in the BTI index project.
Overarching issue: https://github.com/scylladb/scylladb/issues/19191
Previous part: https://github.com/scylladb/scylladb/pull/25506/
Next part: plugging the BTI index readers and writers into sstable readers and writers.
The new code added in this PR isn't used outside of tests yet, but it's posted as a separate PR for reviewability.
This series implements, on top of the key translation logic, and abstract trie writing and traversal logic, a writer and a reader of sstable index files (which map primary keys to positions in Data.db), as described in f16fb6765b/src/java/org/apache/cassandra/io/sstable/format/bti/BtiFormat.md.
Caveats:
1. I think the added test has reasonable coverage, but that depends on running it multiple times. (Though it shouldn't need more than a few runs to catch any bug it covers). It's somewhat awkward as a test meant for running in CI, it's better as something you run many times after a relevant change.
2. These readers and writers are intended to be compatible with Cassandra, but I did *NOT* do any compatibility testing. The writers and readers added here have only been tested against each other, not against Cassandra's readers and writers.
3. This didn't undergo any proper benchmarking and optimization work. I was doing some measurements in the past, but everything was rewritten so much since then that the my old measurements are effectively invalidated. Frankly I have no idea what the performance of all this branchy-branchy logic is now.
No backports needed, new functionality.
Closes scylladb/scylladb#25626
* github.com:scylladb/scylladb:
test/manual: add bti_cassandra_compatibility_test
test/lib/random_schema: add some constraints for generated uuid and time/date values
test/lib/random_utils: add a variant of get_bytes which takes an `engine&`
test/boost: add bti_index_test
sstables/writer: add an accessor for the current write position in Data.db
sstables/trie: introduce bti_index_reader
sstables/trie: add bti_partition_index_writer.cc
sstables/trie: add bti_row_index_writer.cc
utils/bit_cast: add a new overload of write_unaligned()
sstables/trie: add trie_writer::add_partial()
sstables/consumer: add read_56()
sstables/trie: make bti_node_reader::page_ptr copy-constructible
sstables: extract abstract_index_reader from index_reader.hh to its own header
sstables/trie: add an accessor to the file_writer under bti_node_sink
sstables/types: make `deletion_time::operator tombstone()` const
sstables/types: add sstables::deletion_time::make_live()
sstables/trie: fix a special case in max_offset_from_child
sstables/trie: handle `partition_region`s other than `clustered` in BTI position encoding
sstables/trie: rewrite lcb_mismatch to handle fragment invalidation
test/boost/bti_key_translation_test: fix a compilation error hidden behind `if constexpr`
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:
-
Some simple tests that check stand-alone C++ functions or classes use Boost's
BOOST_AUTO_TEST_CASE. -
Some tests require Seastar features, and need to be declared with Seastar's extensions to Boost.Test, namely
SEASTAR_TEST_CASE. -
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()ordo_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.