What happened?
When the Jaeger backend is unavailable or returns an error, the Search page
displays raw HTTP error messages directly inside the form fields:
- Below the "Service" dropdown: "Error loading services: Failed to fetch services: 502 Bad Gateway"
- Below the "Span Name" dropdown: "Error loading operations: Failed to fetch span names for service "frontend": 502 Bad Gateway"
These errors appear immediately on page load before the user interacts with anything.
The messages are raw internal HTTP error strings exposed directly to the user, with
no icon, no container, and no margin separating them from the next form label below.
Additionally, the second error ("Failed to fetch span names for service frontend")
fires on load even though the user never selected the "frontend" service — implying
the app auto-queries span names for a cached/default service without user intent.
Steps to reproduce
- Start Jaeger UI (pnpm start) without a running Jaeger backend
- Navigate to http://localhost:5173/search
- Observe the Search form on the left panel
- Notice the red error text appearing below the "Service" and "Span Name" dropdowns immediately on load
- Switch to Light mode (click the theme toggle in the top right) to see the errors more clearly
Expected behavior
When the backend is unavailable:
- The Service and Span Name dropdowns should show a subtle, user-friendly indicator
(e.g., a warning icon or greyed-out placeholder like "Backend unavailable")
- The raw HTTP error string should NOT be shown to the user
- The service count should show "Service (–)" or no count, rather than "Service (0)"
which incorrectly implies zero services exist
- No auto-query for span names should fire before the user selects a service
Relevant log output
Failed to fetch services: 502 Bad Gateway
Failed to fetch span names for service "frontend": 502 Bad Gateway
Screenshot
Additional context
The issue exists in both dark and light themes. In light mode, the bright red error
text on a white background is especially jarring and makes the UI appear broken even
to users who understand the backend may not be connected.
Jaeger backend version
No response
SDK
No response
Pipeline
No response
Stogage backend
No response
Operating system
No response
Deployment model
No response
Deployment configs
What happened?
When the Jaeger backend is unavailable or returns an error, the Search page
displays raw HTTP error messages directly inside the form fields:
These errors appear immediately on page load before the user interacts with anything.
The messages are raw internal HTTP error strings exposed directly to the user, with
no icon, no container, and no margin separating them from the next form label below.
Additionally, the second error ("Failed to fetch span names for service frontend")
fires on load even though the user never selected the "frontend" service — implying
the app auto-queries span names for a cached/default service without user intent.
Steps to reproduce
Expected behavior
When the backend is unavailable:
(e.g., a warning icon or greyed-out placeholder like "Backend unavailable")
which incorrectly implies zero services exist
Relevant log output
Screenshot
Additional context
The issue exists in both dark and light themes. In light mode, the bright red error
text on a white background is especially jarring and makes the UI appear broken even
to users who understand the backend may not be connected.
Jaeger backend version
No response
SDK
No response
Pipeline
No response
Stogage backend
No response
Operating system
No response
Deployment model
No response
Deployment configs