5f55787e50
initial implementation to support CDC in tablets-enabled keyspaces. The design is described in https://docs.google.com/document/d/1qO5f2q5QoN5z1-rYOQFu6tqVLD3Ha6pphXKEqbtSNiU/edit?usp=sharing It is followed closely for the most part except "Deciding when to change streams" - instead, streams are changed synchronously with tablet split / merge. Instead of the stream switching algorithm with the double writes, we use a scheme similar to the previous method for vnodes - we add the new streams with timestamp that is sufficiently far into the future. In this PR we: * add new group0-based internal system tables for tablet stream metadata and loading it into in-memory CDC metadata * add virtual tables for CDC consumers * the write coordinator chooses a stream by looking up the appropriate stream in the CDC metadata * enable creating tables with CDC enabled in tablets-enabled keyspaces. tablets are allocated for the CDC table, and a stream is created per each tablet. * on tablet resize (split / merge), the topology coordinator creates a new stream set with a new stream for each new tablet. * the cdc tablets are co-located with the base tablets Fixes https://github.com/scylladb/scylladb/issues/22576 backport not needed - new feature update dtests: https://github.com/scylladb/scylla-dtest/pull/5897 update java cdc library: https://github.com/scylladb/scylla-cdc-java/pull/102 update rust cdc library: https://github.com/scylladb/scylla-cdc-rust/pull/136 Closes scylladb/scylladb#23795 * github.com:scylladb/scylladb: docs/dev: update CDC dev docs for tablets doc: update CDC docs for tablets test: cluster_events: enable add_cdc and drop_cdc test/cql: enable cql cdc tests to run with tablets test: test_cdc_with_alter: adjust for cdc with tablets test/cqlpy: adjust cdc tests for tablets test/cluster/test_cdc_with_tablets: introduce cdc with tablets tests cdc: enable cdc with tablets topology coordinator: change streams on tablet split/merge cdc: virtual tables for cdc with tablets cdc: generate_stream_diff helper function cdc: choose stream in tablets enabled keyspaces cdc: rename get_stream to get_vnode_stream cdc: load tablet streams metadata from tables cdc: helper functions for reading metadata from tables cdc: colocate cdc table with base cdc: remove streams when dropping CDC table cdc: create streams when allocating tablets migration_listener: add on_before_allocate_tablet_map notification cdc: notify when creating or dropping cdc table cdc: move cdc table creation to pre_create cdc: add internal tables for cdc with tablets cdc: add cdc_with_tablets feature flag cdc: add is_log_schema helper
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.