June 2026 monthly summary for scylladb/scylla-cluster-tests. Focused on cleaning up deprecated logic and stabilizing test behavior in multi-NIC environments to improve reliability, reduce maintenance debt, and accelerate downstream validation for cluster configurations.

May 2026: Scylla cluster-tests improvements focused on test harness performance, reliability, and maintainability. Key deliverables: 1) Default compaction strategy switched to Incremental Compaction Strategy (ICS) for pre-created schemas, removing dependence on SizeTieredCompactionStrategy and deleting obsolete files/configs (SCT-341). 2) Test harness optimization: cassandra-stress can create/overwrite tables without existence checks, eliminating per-table cfstats overhead and addressing a ~9-hour stall in longevity-5000-tables tests. 3) Repository hygiene: removed obsolete files and configurations related to the old strategy to simplify maintenance. Impact: faster CI/test cycles, more reliable test results, and clearer configuration boundaries. Technologies/skills demonstrated: test harness scripting, performance tuning, configuration management, and code cleanup.

Monthly summary for 2026-03 focused on key business value and technical achievements in scylladb/scylla-cluster-tests. The month delivered robust topology handling, CI enhancements for large-scale tests, and deprecation/fixes that reduce risk and improve stability.

February 2026 monthly summary focusing on key accomplishments, features shipped, and impact for ScyllaDB repositories. Highlights include stability improvements to Scylla GDB test interactions via batch mode and robustness enhancements for distributed cluster management.

January 2026: Focused on reliability improvements, CI maintenance, and test infrastructure enhancements across two repos. Key outcomes include reducing failure noise during decommissioning, simplifying CI configuration, and improving test speed and debuggability with modern GDB integration and flexible test markers, while maintaining compatibility with updated Azure SDKs.

November 2025 monthly summary for scylladb/scylla-cluster-tests. Focused on stabilizing raft topology drain RPC event handling by removing a redundant filter, simplifying the event handling path, and preventing duplicate matches. This change reduces test flakiness and enhances reliability of cluster drain workflows.

October 2025: Focused on improving test reliability and speed for GDB-based debugging in ScyllaDB by introducing a pexpect-driven test harness in the scylladb/scylladb repository. Implemented persistent GDB control with pattern reads and timeouts to reduce flaky failures and shorten test times for the scylla_gdb tests. Updated dependencies by adding python3-pexpect and integrating it into install-dependencies.sh. Included build-tooling optimizations with clang 21.1.8 and toolchain regeneration for improved performance. Linked work to scylladb/scylladb#26419 and scylladb/scylladb#28134. Business value: faster, more reliable debugging feedback and more stable CI.

Monthly summary for 2025-08 focusing on test reliability enhancements in scylla-cluster-tests. Implemented Longevity Test Replication Reliability Fix by increasing n_db_nodes from 3 to 6 to enhance Nemesis test coverage and address replication factor failures. Commit: 8ed6ca0b5f291050112e6e64c4e2e42d9772ca6b. Impact: more stable longevity tests, reduced flakiness under RF=3, improved confidence in cluster stability and release readiness.

Month: 2025-07 – Performance summary for scylla-cluster-tests. Focused on reliability improvements around schema consistency after replication strategy changes. Delivered a targeted bug fix that ensures cluster-wide schema consensus before proceeding with operations, reducing errors due to out-of-sync schemas across nodes. This work enhances stability of test clusters during strategy changes and improves overall test reliability and deployment safety.

June 2025 monthly summary for scylladb/scylla-cluster-tests focused on improving parameter clarity in CI documentation. Delivered a targeted documentation clarification for scylla_repo and byo_scylla_repo inputs, reducing misconfiguration risk and support friction. The change is anchored by commit f07e37342849130aad273118d7c59b5250d05587, which explains that scylla_repo expects a GitHub repository URL while byo_scylla_repo expects a YUM repository URL, with added section breaks for readability. This work enhances developer experience, lowers onboarding time for new contributors, and improves CI stability by ensuring correct parameter usage.

April 2025 focused on strengthening performance verification for dictionary compression in scylla-cluster-tests. Delivered Dictionary Compression Performance Testing for LZ4 and Zstd, including new configuration files and Jenkins pipeline scripts to validate latency is unaffected and to benchmark regressions. Commit 3988be290645b072a568072ded0f09b6cddf3320 documents the change. No major bugs fixed this month. Impact: improved CI coverage and measurable safeguards for deployment decisions around dictionary compression, reducing risk of latency regressions in production. Technologies/skills demonstrated: performance testing, benchmark design, CI/CD automation (Jenkins), configuration management, LZ4 and Zstd compression.

February 2025 monthly summary for scylladb/scylla-cluster-tests focusing on reliability and accuracy improvements in Tablet Feature Enablement detection and table listing for counter columns. Delivered two bug fix patches with config-based detection and argument handling corrections, and counter-table filtering enhancements, contributing to more stable CI and trustworthy feature flags.

January 2025 monthly summary for scylladb/scylla-cluster-tests focused on improving test reliability and aligning test configurations with production behavior. Deliverable: corrected test configuration to use IncrementalCompactionStrategy (ICS) for longevity tests, replacing STCS. Change applied across the longevity YAML ics-longevity-50GB-4days-authorization-and-tls-ssl.yaml to reflect intended compaction strategy in all relevant write/read commands. Commit linked: 7b847264c5b01ca52f3efce1880ef4384326d7b3 (fix(ics-longevity-50GB-4days-authorization-and-tls-ssl.yaml): replace STCS with ICS).