# Specification: Roadmap Phase IV - Advanced Intelligence & Ecosystem

## Context

Phase IV refocuses MySQLTuner-perl on proactive intelligence, lifecycle management, and deeper ecosystem integration. As database environments migrate to modern LTS versions and specialized clusters, the advisor must provide higher-level insights beyond basic variable tuning.

## Proposed Intelligence & Ecosystem Features

### 1. Smart Migration LTS Advisor

* **Goal**: Minimize risks during major version upgrades (e.g., MySQL 8.0 to 8.4 or 9.x).
* **Indicators**:
  * **Variable Deprecation**: Identify used variables that are removed or changed in the target version.
  * **Engine Compatibility**: Audit character set (e.g., `utf8mb3` to `utf8mb4`) and collation migration risks.
  * **SQL Mode Audit**: Detect incompatible `sql_mode` settings that might break legacy queries.
* **Output**: A specific "Upgrade Risk Report" section in the recommendations.

### 2. Weighted Health Score

* **Goal**: Provide a single KPI (0-100) that reflects the overall instance health.
* **Logic**:
  * **Performance (40%)**: Cache hits, I/O pressure, lock contention.
  * **Security (30%)**: Authentication plugins, CVE exposure, network hardening.
  * **Resilience (30%)**: Replication health, binlog/redo log safety, backup-ready state.
* **Output**: A prominent health badge at the top of the report.

### 3. Predictive Capacity Planning

* **Goal**: Forecast resource exhaustion before it impacts production.
* **Logic**:
  * **Growth Forecasting**: Analyze binlog write throughput and table metadata to estimate disk exhaustion date.
  * **Memory Headroom**: Correlate traffic peak patterns with `max_connections` and per-thread memory to forecast OOM risks.
* **Output**: "Capacity Forecast" markers in the resource summary.

### 4. Cluster & Replication Intelligence

* **Goal**: Deep diagnostics for modern distributed topologies.
* **Logic**:
  * **LAG Root Cause**: Differentiate between IO thread delay (network/source) and SQL thread delay (concurrency/contention).
  * **GTID & Multi-Source**: Consistency auditing for complex replication chains and channel-specific tuning.
* **Output**: Multi-channel replication status dashboard.

### 5. Security Hardening 2.0

* **Goal**: Move from "configuration checks" to "vulnerability awareness".
* **Logic**:
  * **CVE Mapping**: Version-based exposure detection against known community databases.
  * **Encryption Audit**: Advanced validation for TDE (Transparent Data Encryption) and SSL/TLS cipher suite strength.
* **Output**: Dedicated security compliance matrix.

### 6. Guided Auto-Fix Engine

* **Goal**: Bridge the gap between "Advice" and "Action".
* **Logic**:
  * **Interactive Simulation**: Allow users to see the predicted impact of a suggested change before applying.
  * **Configuration Snippets**: Generate copy-pasteable `SET GLOBAL` commands or `my.cnf` blocks tailored to the environment.
* **Output**: "Ready-to-Apply" code blocks at the end of the report.

## Expected Value

* **Decision Support**: Higher quality information for DBAs and SREs during migrations and scaling.
* **Business Visibility**: Clear KPIs for stakeholders via the Health Score.
* **Operational Speed**: Faster time-to-fix with the Auto-Fix engine.
