Connections Troubleshooting

Connections bring your data into OpenIndustrial. When they have issues, everything downstream stops. This guide covers common connection problems and their solutions.

---

Connection Health Check

Quick checks in order:

1. Status indicator - Is the connection showing "Connected"?
2. Data flow - Are you seeing incoming data?
3. Timestamps - Is data recent (not stale)?

---

Common Issues

Connection Shows "Error"

Symptoms:

• Red status indicator
• No data flowing
• Error message in connection details

Diagnosis:

1. Open the connection to see the error details
2. Check the error message (see error reference below)
3. Verify credentials are correct

Common causes:

• Credentials expired or rotated
• Network configuration changed
• Source resource deleted or modified

Connection Shows "Connected" But No Data

Symptoms:

• Green status indicator
• Surface shows no data
• Queries return empty

Diagnosis:

1. Is the source actually sending data?
2. Is the connection linked to the right surface?
3. Check for data filtering issues

Data Is Delayed

Symptoms:

• Timestamps are old
• Data arrives in batches
• Real-time queries show stale data

Possible causes:

• Network latency
• Source batching behavior
• Time zone configuration
• Consumer group contention

---

Connection Types

IoT Hub Connections

Specific requirements:

• Connection string must be Hub-level (not device-level)
• Policy needs ServiceConnect permission
• Consumer group must be dedicated

Common mistakes:

Mistake	Symptom	Fix
Device connection string	Auth fails	Use Hub connection string
Wrong policy	Permission denied	Use iothubowner or custom with ServiceConnect
Shared consumer group	Intermittent data	Create dedicated consumer group

Event Hub Connections

Specific requirements:

• Connection string must include EntityPath
• Consumer group must exist
• Partition count matters for parallel reading

Common mistakes:

Mistake	Symptom	Fix
Missing EntityPath	Resource not found	Add EntityPath to connection string
Consumer group missing	Connection fails	Create consumer group in Azure
Wrong namespace	Not found	Check namespace spelling

---

Error Reference

"Invalid connection string"

Cause: Malformed connection string format

Fix:

1. Copy fresh from Azure Portal
2. Don't modify the string
3. Check for truncation

"Authentication failed"

Cause: Invalid or expired credentials

Fix:

1. Verify key in Azure Portal
2. Update connection with new key
3. Check policy permissions

"Consumer group not found"

Cause: Specified consumer group doesn't exist

Fix:

1. Create consumer group in Azure
2. Use existing consumer group name
3. Default is "$Default"

"Connection timeout"

Cause: Network or firewall issue

Fix:

1. Check network connectivity
2. Verify firewall allows OI IPs
3. Check proxy settings if applicable

---

Creating New Connections

Two ways to create:

1. Drag-and-drop - Create connection widget, configure manually
2. Ask Azi - "Create a connection for my IoT Hub"

Either way, Azi validates your configuration before applying changes.

---

Testing Connections

Before relying on a connection:

1. Verify data source is sending data (check in Azure Portal)
2. Create connection in OpenIndustrial
3. Link to a test surface
4. Build a simple query: YourTable | take 10
5. Verify data appears

---

Ask Azi

In chat, try:

• "Why is my IoT Hub connection failing?"
• "Help me configure an Event Hub connection"
• "Diagnose this connection error: [paste error]"

---

Related

• Can't Connect - Authentication and connectivity issues
• No Data Showing - When connection works but no data appears
• Surfaces Troubleshooting - Issues with surfaces linked to connections