ColumnStore Stability Improvements

This epic focuses on improving the overall stability and robustness of MariaDB ColumnStore across core services, query execution, and multi-node orchestration. The goal is to reduce unplanned failures, eliminate edge-case crashes, and ensure predictable, consistent behavior under load or failure conditions.

Stability work targets the foundation: tightening memory handling, improving fault tolerance, hardening error paths, and reducing variability across environments (bare metal, containers, cloud). We prioritize fixes and improvements that require minimal tuning, reduce operational surprise, and improve trust in ColumnStore at scale.

Key objectives include:

• Address memory leaks, race conditions, and crash loops
• Improve error reporting and diagnosability
• Ensure subprocesses recover cleanly from failure
• Prevent query-level instability (e.g., Views, CTE, group_concat(), group by edge cases)
• Improve reliability during hardware issues, node restarts, or network splits

This body of work addresses issues that hinder ColumnStore from being a reliable analytical engine in production environments.