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DATA PERSISTENCE IMPLEMENTATION CHECKLIST
Issue #1: Database Storage for Crash Recovery
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PHASE 1: DATABASE SETUP
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[ ] Connect to MySQL/MariaDB database
[ ] Execute create_session_state_table.sql
[ ] Verify table exists:
    SQL: SHOW TABLES LIKE 'session_state';
[ ] Verify table structure:
    SQL: DESCRIBE session_state;
[ ] Test database permissions (INSERT, UPDATE)

PHASE 2: MODIFY MACHINE CYCLES FUNCTION
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[ ] Open Node-RED editor
[ ] Locate "Machine cycles" function node
[ ] Double-click to edit
[ ] Change "Outputs" from 2 to 3
[ ] Replace function code with contents from:
    modified_machine_cycles.js
[ ] Click "Done"
[ ] Add new MySQL node named "Session State DB"
[ ] Configure MySQL node with database credentials
[ ] Wire Machine Cycles output 3 → Session State DB
[ ] Deploy changes

PHASE 3: MODIFY WORK ORDER BUTTONS FUNCTION
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[ ] Locate "Work Order buttons" function node
[ ] Double-click to edit
[ ] Change "Outputs" from 4 to 5
[ ] Replace function code with contents from:
    modified_work_order_buttons.js
[ ] Click "Done"
[ ] Wire Work Order Buttons output 5 → Session State DB (same node as above)
[ ] Deploy changes

PHASE 4: CREATE STARTUP RECOVERY FLOW
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4.1 - Startup Trigger
[ ] Add Inject node
[ ] Configure:
    - Name: "Startup Trigger"
    - Inject once after: 0.1 seconds
    - Repeat: none
[ ] Click "Done"

4.2 - Query Function
[ ] Add Function node
[ ] Configure:
    - Name: "Query Previous Session"
    - Outputs: 1
    - Code: Copy from startup_recovery_query.js
[ ] Wire: Startup Trigger → Query Previous Session
[ ] Click "Done"

4.3 - Database Query
[ ] Wire: Query Previous Session → Session State DB

4.4 - Process Response
[ ] Add Function node
[ ] Configure:
    - Name: "Process Recovery Response"
    - Outputs: 2
    - Code: Copy from process_recovery_response.js
[ ] Wire: Session State DB → Process Recovery Response
[ ] Click "Done"

4.5 - Deactivate Stale Sessions
[ ] Wire: Process Recovery Response output 1 → Session State DB

4.6 - User Prompt UI
[ ] Option A: Add ui_toast node
    - Name: "Recovery Prompt"
    - Position: top right
    - Duration: 5 seconds
[ ] Option B: Add ui_template node for modal (see NODE_CONFIGURATION.md)
[ ] Wire: Process Recovery Response output 2 → Prompt UI
[ ] Click "Done"

4.7 - Restore Session Function
[ ] Add Function node
[ ] Configure:
    - Name: "Restore Session"
    - Outputs: 2
    - Code: Copy from restore_session.js
[ ] Wire: User "Restore" action → Restore Session
[ ] Wire: Restore Session output 1 → Session State DB
[ ] Wire: Restore Session output 2 → Success notification UI
[ ] Click "Done"

4.8 - Start Fresh Function
[ ] Add Function node
[ ] Configure:
    - Name: "Start Fresh"
    - Outputs: 2
    - Code: Copy from start_fresh.js
[ ] Wire: User "Start Fresh" action → Start Fresh
[ ] Wire: Start Fresh output 1 → Session State DB
[ ] Wire: Start Fresh output 2 → Success notification UI
[ ] Click "Done"

4.9 - Deploy
[ ] Deploy all changes
[ ] Check debug panel for errors

PHASE 5: ADD DEBUG NODES (RECOMMENDED)
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[ ] Add debug node after Session State DB
    Name: "Debug Session Sync"
[ ] Add debug node after Process Recovery Response output 2
    Name: "Debug Recovery Data"
[ ] Add debug node after Restore Session output 2
    Name: "Debug Restore Status"
[ ] Deploy changes

PHASE 6: TESTING
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Test 1: Normal Operation
[ ] Start a work order
[ ] Click START button
[ ] Run several machine cycles (5-10)
[ ] Check debug panel for session-sync messages
[ ] Query database:
    SQL: SELECT * FROM session_state WHERE is_active = 1;
[ ] Verify data updates every ~5 seconds
[ ] Verify cycle_count increments
[ ] Verify operating_time increases

Test 2: Crash Recovery (Simulated)
[ ] Start work order and run 20+ cycles
[ ] Note current cycle count
[ ] Stop Node-RED:
    Command: sudo systemctl stop nodered
[ ] Wait 10 seconds
[ ] Verify session in database:
    SQL: SELECT * FROM session_state WHERE is_active = 1;
[ ] Restart Node-RED:
    Command: sudo systemctl start nodered
[ ] Wait for recovery prompt (should appear within 5 seconds)
[ ] Verify prompt shows correct data:
    - Work order ID
    - Cycle count
    - Operating time
    - Last update time
[ ] Click "Restore Session"
[ ] Verify success message
[ ] Check active work order in dashboard
[ ] Run more cycles
[ ] Verify cycle count continues from previous value

Test 3: Start Fresh Option
[ ] Start work order and run cycles
[ ] Stop and restart Node-RED
[ ] When recovery prompt appears, click "Start Fresh"
[ ] Verify success message
[ ] Check database - old session should be deactivated:
    SQL: SELECT * FROM session_state WHERE session_id = 'OLD_SESSION_ID';
    (is_active should be 0)
[ ] Verify all counters reset to 0
[ ] Start new work order
[ ] Verify normal operation

Test 4: Stale Session Detection
[ ] Insert old session (25 hours ago):
    SQL: UPDATE session_state
         SET updated_at = updated_at - (25 * 60 * 60 * 1000)
         WHERE is_active = 1;
[ ] Restart Node-RED
[ ] Verify system detects stale session
[ ] Verify automatic start fresh (no prompt)
[ ] Check logs for stale session warning

Test 5: Multiple Restarts
[ ] Start work order, run cycles
[ ] Restart Node-RED 3 times in a row
[ ] Each time, restore the session
[ ] Verify cycle count accumulates correctly
[ ] Verify no data loss across restarts

PHASE 7: VERIFICATION
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[ ] Database table created successfully
[ ] Modified functions deployed
[ ] Recovery flow deployed
[ ] All wiring correct
[ ] All tests passed
[ ] No errors in Node-RED log:
    Command: journalctl -u nodered -n 50
[ ] No errors in MySQL log
[ ] Debug output shows expected behavior
[ ] Dashboard shows recovery prompts correctly

PHASE 8: CLEANUP (OPTIONAL)
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[ ] Remove debug nodes (keep for troubleshooting)
[ ] Add comments to function nodes
[ ] Document custom UI templates
[ ] Create backup of flows.json:
    Command: cp flows.json flows.json.backup_persistence
[ ] Test backup restoration procedure

PHASE 9: MONITORING SETUP
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[ ] Set up database monitoring query (optional):
    SQL: SELECT COUNT(*) as active_sessions
         FROM session_state WHERE is_active = 1;
[ ] Add dashboard tile showing last session sync time
[ ] Configure alerts for stale sessions (optional)
[ ] Document recovery procedures for operators

TROUBLESHOOTING CHECKLIST
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If sync not working:
[ ] Check MySQL node configuration
[ ] Check database user permissions
[ ] Check for SQL syntax errors in debug panel
[ ] Verify msg.topic contains valid SQL
[ ] Check network connectivity to database

If recovery not working:
[ ] Check inject node fires on startup
[ ] Verify session_state table has data
[ ] Check SQL query in startup_recovery_query.js
[ ] Verify process_recovery_response.js outputs
[ ] Check UI notification configuration

If data incorrect after restore:
[ ] Verify JSON serialization in database
[ ] Check single quote escaping in SQL
[ ] Verify timestamp format (milliseconds)
[ ] Check global.get/set calls in restore function

PERFORMANCE VERIFICATION
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[ ] Database writes ~every 5 seconds during production
[ ] No lag or delays in UI
[ ] Node-RED CPU usage < 50%
[ ] Database connection stable
[ ] No connection pool exhaustion

Expected database write frequency:
  Normal operation: ~12 writes/minute
  Active production: ~12-15 writes/minute
  Idle (no cycles): 0 writes/minute

DOCUMENTATION
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[ ] Read IMPLEMENTATION_GUIDE.md
[ ] Read IMPLEMENTATION_SUMMARY.md
[ ] Read NODE_CONFIGURATION.md
[ ] Bookmark optimization_prompt.txt
[ ] Document any custom changes made
[ ] Share recovery procedures with operators
[ ] Train operators on recovery prompts

SIGN-OFF
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Implementation Date: ___________________________
Implemented By: _________________________________
Tests Passed: [ ] All  [ ] Some (document failures below)
Production Ready: [ ] Yes  [ ] No

Notes:
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________

NEXT STEPS
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After successful implementation and testing:
[ ] Proceed to Issue #4: Intelligent Downtime Categorization
[ ] Proceed to Issue #5: Session Management and Pattern Tracking
[ ] Proceed to Issue #2: Cycle Count Capping
[ ] Proceed to Issue #3: Hardware Irregularity Tracking

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END OF CHECKLIST
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Reference Files:
  Database Schema: create_session_state_table.sql
  Modified Functions: modified_machine_cycles.js
                     modified_work_order_buttons.js
  Recovery Functions: startup_recovery_query.js
                     process_recovery_response.js
                     restore_session.js
                     start_fresh.js
  Documentation: IMPLEMENTATION_GUIDE.md
                IMPLEMENTATION_SUMMARY.md
                NODE_CONFIGURATION.md

For support, check Node-RED logs:
  journalctl -u nodered -f