7ccb50514d
This patch introduces `view_building_coordinator`, a single entity within whole cluster responsible for building tablet-based views. The view building coordinator takes slightly different approach than the existing node-local view builder. The whole process is split into smaller view building tasks, one per each tablet replica of the base table. The coordinator builds one base table at a time and it can choose another when all views of currently processing base table are built. The tasks are started by setting `STARTED` state and they are executed by node-local view building worker. The tasks are scheduled in a way, that each shard processes only one tablet at a time (multiple tasks can be started for a shard on a node because a table can have multiple views but then all tasks have the same base table and tablet (last_token)). Once the coordinator starts the tasks, it sends `work_on_view_building_tasks` RPC to start the tasks and receive their results. This RPC is resilient to RPC failure or raft leader change, meaning if one RPC call started a batch of tasks but then failed (for instance the raft leader was changed and caller aborted waiting for the response), next RPC call will attach itself to the already started batch. The coordinator plugs into handling tablet operations (migration/resize/RF change) and adjusts its tasks accordingly. At the start of each tablet operation, the coordinator aborts necessary view building tasks to prevent https://github.com/scylladb/scylladb/issues/21564. Then, new adjusted tasks are created at the end of the operation. If the operation fails at any moment, aborted tasks are rollback. The view building coordinator can also handle staging sstables using process_staging view building tasks. We do this because we don't want to start generating view updates from a staging sstable prematurely, before the writes are directed to the new replica (https://github.com/scylladb/scylladb/issues/19149). For detailed description check: `docs/dev/view-building-coordinator.md` Fixes https://github.com/scylladb/scylladb/issues/22288 Fixes https://github.com/scylladb/scylladb/issues/19149 Fixes https://github.com/scylladb/scylladb/issues/21564 Fixes https://github.com/scylladb/scylladb/issues/17603 Fixes https://github.com/scylladb/scylladb/issues/22586 Fixes https://github.com/scylladb/scylladb/issues/18826 Fixes https://github.com/scylladb/scylladb/issues/23930 --- This PR is reimplementation of https://github.com/scylladb/scylladb/pull/21942 Closes scylladb/scylladb#23760 * github.com:scylladb/scylladb: test/cluster: add view build status tests test/cluster: add view building coordinator tests utils/error_injection: allow to abort `injection_handler::wait_for_message()` test: adjust existing tests utils/error_injection: add injection with `sleep_abortable()` db/view/view_builder: ignore `no_such_keyspace` exception docs/dev: add view building coordinator documentation db/view/view_building_worker: work on `process_staging` tasks db/view/view_building_worker: register staging sstable to view building coordinator when needed db/view/view_building_worker: discover staging sstables db/view/view_building_worker: add method to register staging sstable db/view/view_update_generator: add method to process staging sstables instantly db/view/view_update_generator: extract generating updates from staging sstables to a method db/view/view_update_generator: ignore tablet-based sstables db/view/view_building_coordinator: update view build status on node join/left db/view/view_building_coordinator: handle tablet operations db/view: add view building task mutation builder service/topology_coordinator: run view building coordinator db/view: introduce `view_building_coordinator` db/view/view_building_worker: update built views locally db/view: introduce `view_building_worker` db/view: extract common view building functionalities db/view: prepare to create abstract `view_consumer` message/messaging_service: add `work_on_view_building_tasks` RPC service/topology_coordinator: make `term_changed_error` public db/schema_tables: create/cleanup tasks when an index is created/dropped service/migration_manager: cleanup view building state on drop keyspace service/migration_manager: cleanup view building state on drop view service/migration_manager: create view building tasks on create view test/boost: enable proxy remote in some tests service/migration_manager: pass `storage_proxy` to `prepare_keyspace_drop_announcement()` service/migration_manager: coroutinize `prepare_new_view_announcement()` service/storage_proxy: expose references to `system_keyspace` and `view_building_state_machine` service: reload `view_building_state_machine` on group0 apply() service/vb_coordinator: add currently processing base db/system_keyspace: move `get_scylla_local_mutation()` up db/system_keyspace: add `view_building_tasks` table db/view: add view_building_state and views_state db/system_keyspace: add method to get view build status map db/view: extract `system.view_build_status_v2` cql statements to system_keyspace db/system_keyspace: move `internal_system_query_state()` function earlier db/view: ignore tablet-based views in `view_builder` gms/feature_service: add VIEW_BUILDING_COORDINATOR feature
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.