7f843e0a5c
Fix an issue in the voter calculator where existing voters were not retained across data centers and racks in certain scenarios. This occurred when voters were distributed across more data centers and racks than the maximum allowed number of voters. Previously, the prioritization logic for data centers and racks did not consider the number of existing assigned voters. It only prioritized nodes within a single data center or rack, which could result in unnecessary reassignment of voters. Improved the prioritization logic to account for the number of existing assigned voters in each data center and rack. Additionally, the limited voters feature did not account for the existing topology coordinator (Raft leader) when selecting voters to be removed. As a result, the limited voters calculator could inadvertently remove the votership of the topology coordinator, triggering unnecessary Raft leader re-election. To address this, the topology coordinator's votership status is now preserved unless absolutely necessary. When choosing between otherwise equivalent voters, the node other than the existing topology coordinator is prioritized for removal. This change ensures a more stable voter distribution and reduces unnecessary voter reassignments. The limited voters calculator is refactored to use a priority queue for sorting nodes by their priorities. This change simplifies the voter selection logic and makes it more extensible for future enhancements, such as supporting more complex priority calculations. Fixes: scylladb/scylladb#23950 Fixes: scylladb/scylladb#23588 Fixes: scylladb/scylladb#23786 No backport: The limited voters feature is currently only present in master. Closes scylladb/scylladb#23888 * https://github.com/scylladb/scylladb: raft: ensure topology coordinator retains votership raft: retain existing voters across data centers and racks raft: refactor limited voters calculator to prioritize nodes raft: replace pointer with reference for non-null output parameter raft: reduce code duplication in group0 voter handler raft: unify and optimize datacenter and rack info creation
Scylla in-source tests.
For details on how to run the tests, see docs/dev/testing.md
Shared C++ utils, libraries are in lib/, for Python - pylib/
alternator - Python tests which connect to a single server and use the DynamoDB API unit, boost, raft - unit tests in C++ cqlpy - Python tests which connect to a single server and use CQL topology* - tests that set up clusters and add/remove nodes cql - approval tests that use CQL and pre-recorded output rest_api - tests for Scylla REST API Port 9000 scylla-gdb - tests for scylla-gdb.py helper script nodetool - tests for C++ implementation of nodetool
If you can use an existing folder, consider adding your test to it. New folders should be used for new large categories/subsystems, or when the test environment is significantly different from some existing suite, e.g. you plan to start scylladb with different configuration, and you intend to add many tests and would like them to reuse an existing Scylla cluster (clusters can be reused for tests within the same folder).
To add a new folder, create a new directory, and then
copy & edit its suite.ini.