add rule based auto tagging user guide PR

Signed-off-by: Kaushal Kumar <ravi.kaushal97@gmail.com>

Author: kaushalmahi12

_tuning-your-cluster/availability-and-recovery/workload-management/autotagging.md

@@ -0,0 +1,182 @@
+---
+layout: default
+title: Auto-tagging Feature Overview
+nav_order: 20
+parent: Workload management
+grand_parent: Availability and recovery
+---
+
+# Rule-based Auto-tagging in OpenSearch
+
+## What is Rule-based Auto-tagging?
+
+Rule-based Auto-tagging automatically assigns workload groups to incoming search requests in OpenSearch. This feature helps you implement automated workload management policies without manual intervention.
+
+## Key Concepts
+
+- **Rule**: Defines criteria for tagging search requests
+- **Index Pattern**: Prefix-based pattern matching target indices (e.g., "logs-*")
+- **Workload Group**: Label assigned to requests for workload management
+- **Auto-tagging**: Process of assigning workload groups based on rules
+- **Pattern Specificity**: More specific patterns take precedence e,g; `logs-prod-2025` will match `logs-prod-*` pattern over `logs-*`
+
+## How to Set Up Rule-based Auto-tagging
+
+### Before You Begin
+
+- Ensure you have an OpenSearch cluster with the workload-management plugin installed
+- Verify you have administrative access to the cluster
+
+### Managing Rules
+
+Create or update a rule:
+```http
+PUT /_rules/workload_group
+{
+    "description": "Production Logs Rule",
+    "index_pattern": ["prod-logs-*"],
+    "workload_group": "production_workload"
+}
+```
+
+List all rules:
+```http
+GET /_rules/workload_group
+```
+
+Delete a rule:
+```http
+DELETE /_rules/workload_group/{rule_id}
+```
+
+### Rule Structure
+```json
+{
+    "_id": "fwehf8302582mglfio349==",  // System-generated
+    "description": "Assign Query Group for Index Logs123",
+    "index_pattern": ["logs123"],  // Exact match or prefix pattern only
+    "workload_group": "dev_workload_group_id",
+    "updated_at": "01-10-2025T21:23:21.456Z"  // System-generated timestamp
+}
+```
+
+## How Pattern Matching Works
+
+### Supported Pattern Types
+
+1. Exact matches: `logs-2025-04`
+2. Prefix patterns: `logs-2025-*`
+
+Note: OpenSearch doesn't support suffix patterns (`*-logs`) or generic patterns (`*-logs-*`).
+
+### Pattern Precedence
+
+1. Exact matches have highest priority
+2. Longer prefix patterns take precedence over shorter ones
+   Example: `logs-prod-2025-*` is more specific than `logs-prod-*`
+
+### Evaluation Process
+
+1. OpenSearch receives a search request
+2. The system compares request indices against defined rules
+3. The most specific matching rule's workload group is applied
+4. If no rules match, no workload group is assigned
+
+## Examples
+
+### Production vs Development Logs
+
+```json
+// Rule 1: Production Logs
+{
+    "description": "Production Logs",
+    "index_pattern": ["logs-prod-*"],
+    "workload_group": "production"
+}
+
+// Rule 2: Development Logs
+{
+    "description": "Development Logs",
+    "index_pattern": ["logs-dev-*"],
+    "workload_group": "development"
+}
+
+// Example: Production search
+GET /logs-prod-2025/_search
+// Result: Tagged with "production"
+
+// Example: Development search
+GET /logs-dev-2025/_search
+// Result: Tagged with "development"
+```
+
+### Handling Specificity
+
+```json
+// Rule 1: General Logs
+{
+    "description": "General Logs",
+    "index_pattern": ["logs-*"],
+    "workload_group": "general"
+}
+
+// Rule 2: Production Service Logs
+{
+    "description": "Production Service Logs",
+    "index_pattern": ["logs-prod-service-*"],
+    "workload_group": "prod_service"
+}
+
+// Example: Specific production service search
+GET /logs-prod-service-2025/_search
+// Result: Tagged with "prod_service" (more specific match wins)
+```
+
+## Benefits of Rule-based Auto-tagging
+
+- Automates request tagging
+- Ensures consistent policy application
+- Scales to new indices automatically
+- Reduces administrative overhead
+- Minimizes manual errors
+- Centralizes workload management
+- Allows easy policy updates
+
+## Best Practices
+
+### Designing Rules
+
+1. Use specific prefix patterns for precise control
+2. Clearly document each rule's purpose
+3. Use consistent workload group naming
+4. Create a hierarchical pattern structure
+
+### Creating Patterns
+
+1. Start with the most specific patterns needed
+2. Use consistent delimiters in index names
+3. Avoid unintended pattern overlaps
+4. Plan for future index naming conventions
+
+### Operations
+
+1. Test new rules in a development environment
+2. Monitor rule matches in your logs
+3. Keep rule configurations documented
+4. Regularly review rule effectiveness
+
+## Troubleshooting
+
+**Common issues and solutions:**
+
+1. **No Workload Group Assigned**: Ensure your index pattern is a valid prefix
+2. **Unexpected Workload Group**: Look for more specific matching patterns
+3. **Rule Not Working**: Verify the pattern follows the prefix-only format
+
+**To validate your setup:**
+
+
+- Test new rules with sample requests before production use
+- Use the list rules API to verify pattern matching
+- Check your logs for rule evaluation results
+