LightRAG/logs/2025-12-04-11-45-beastmode-retrieval-tenant-stats-fix.md

Session Log: Fix Retrieval State Clearing and Tenant Card Statistics

Date: 2025-12-04

Summary

Fixed two issues:

1. Retrieval history not being cleared when tenant or KB changes
2. Tenant selection cards showing "0" for KBs, Docs, and GB instead of real figures

Problem 1: Retrieval State Not Clearing

Issue

When switching between tenants or knowledge bases, the retrieval chat history persisted, potentially showing results from a different tenant/KB context.

Root Cause

The RetrievalTesting.tsx component did not have an effect hook to clear the messages state when selectedTenant or selectedKB changed.

Solution

Added a useEffect hook in RetrievalTesting.tsx that:

1. Gets both selectedTenant and selectedKB from useTenantState
2. Clears messages state and retrieval history when tenant or KB changes
3. Logs the clearing action for debugging

Code Changes

File: /lightrag_webui/src/features/RetrievalTesting.tsx

Added import for selectedTenant:

const selectedTenant = useTenantState.use.selectedTenant()
const selectedKB = useTenantState.use.selectedKB()

Added effect to clear history:

// Clear retrieval history when tenant or KB changes to prevent showing stale data
useEffect(() => {
  setMessages([])
  useSettingsStore.getState().setRetrievalHistory([])
  console.log('[RetrievalTesting] Cleared retrieval history due to tenant/KB change:', {
    tenant_id: selectedTenant?.tenant_id,
    kb_id: selectedKB?.kb_id
  })
}, [selectedTenant?.tenant_id, selectedKB?.kb_id])

Problem 2: Tenant Cards Showing Zero Statistics

Issue

The tenant selection cards displayed "0 KBs", "0 Docs", "0 GB" even when tenants had knowledge bases and documents.

Root Cause

The list_tenants method in tenant_service.py was querying the PostgreSQL database but creating Tenant objects with default statistics (0, 0, 0.0) instead of computing them from the knowledge_bases and documents tables.

Solution

Updated the SQL query in list_tenants to use LEFT JOINs to compute:

• kb_count: Count of knowledge bases per tenant
• total_documents: Count of documents per tenant
• total_size_bytes: Sum of file sizes for storage calculation

Code Changes

File: /lightrag/services/tenant_service.py

Updated SQL query:

SELECT
    t.tenant_id,
    t.name,
    t.description,
    t.created_at,
    t.updated_at,
    COALESCE(kb_stats.kb_count, 0) as kb_count,
    COALESCE(doc_stats.doc_count, 0) as total_documents,
    COALESCE(doc_stats.total_size_bytes, 0) as total_size_bytes
FROM tenants t
LEFT JOIN (
    SELECT tenant_id, COUNT(*) as kb_count
    FROM knowledge_bases
    GROUP BY tenant_id
) kb_stats ON t.tenant_id = kb_stats.tenant_id
LEFT JOIN (
    SELECT tenant_id, COUNT(*) as doc_count, COALESCE(SUM(file_size), 0) as total_size_bytes
    FROM documents
    GROUP BY tenant_id
) doc_stats ON t.tenant_id = doc_stats.tenant_id
ORDER BY t.created_at DESC

Updated Tenant object creation to include computed statistics:

tenant = Tenant(
    tenant_id=row['tenant_id'],
    tenant_name=row['name'],
    description=row.get('description', ''),
    created_by=None,
    metadata={},
    kb_count=row.get('kb_count', 0) or 0,
    total_documents=row.get('total_documents', 0) or 0,
    total_storage_mb=total_storage_mb,
)

Additional Fix: fetchTenants API Compatibility

Issue

After the tenant service changes, the frontend fetchTenants function broke because it expected an array but received a paginated response object.

Solution

Updated fetchTenants in /lightrag_webui/src/api/tenant.ts to handle both formats:

export async function fetchTenants(): Promise<Tenant[]> {
  try {
    const response = await apiClient.get('/api/v1/tenants')
    const data = response.data
    if (Array.isArray(data)) {
      return data
    }
    // New paginated format returns { items: [...], total: N, ... }
    return data?.items || []
  } catch (error) {
    console.error('Failed to fetch tenants:', error)
    throw error
  }
}

Verification

• ✅ Frontend build passes (TypeScript, Vite)
• ✅ Python syntax check passes
• ✅ Tenant cards now show correct KB count (e.g., "2 KBs" for both tenants)
• ✅ Retrieval history clears when tenant/KB changes (verified via console logs)
• ✅ Empty KB shows proper empty state (no stale retrieval data)

---

Task Logs

Actions:

• Added useEffect in RetrievalTesting.tsx to clear messages on tenant/KB change
• Updated SQL query in tenant_service.py to compute real statistics with LEFT JOINs
• Fixed fetchTenants API to handle paginated response format

Decisions:

• Used LEFT JOINs for statistics to ensure tenants with no KBs or documents still appear
• Used COALESCE for null safety on aggregates

Next Steps:

• Consider adding refresh button on tenant selection page to update stats
• Monitor for performance impact of JOIN queries on large deployments

Lessons/Insights:

• When adding new API response formats, ensure backward compatibility in frontend consumers
• Tenant statistics should be computed dynamically from source tables rather than stored as cached values