1# Azure Service Bus SDK — Python
2 
3Package: `azure-servicebus` | [README](https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/servicebus/azure-servicebus/) | [Full Troubleshooting Guide](https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/servicebus/azure-servicebus/TROUBLESHOOTING.md)
4 
5## Common Errors
6 
7| Exception | Cause | Fix |
8|-----------|-------|-----|
9| `ServiceBusAuthenticationError` | Invalid credentials | Check connection string, regenerate SAS key |
10| `ServiceBusAuthorizationError` | Missing Send/Listen claim | Assign `Azure Service Bus Data Owner/Sender/Receiver` RBAC role |
11| `ServiceBusConnectionError` | Network or firewall | Check AMQP port 5671, try `TransportType.AmqpOverWebsocket` |
12| `OperationTimeoutError` | Service didn't respond in time | Adjust retry config, verify network |
13| `MessageLockLostError` | Processing exceeded lock duration | Use `AutoLockRenewer`, reduce processing time |
14| `SessionLockLostError` | Session lock expired | Reconnect to session, keep renewing lock |
15| `MessageSizeExceededError` | Message or batch too large | Reduce payload. Premium supports individual messages up to 100MB. Batch limit is computed from max message size on the client, so batches can also be impacted |
16 
17## Enable Logging
18 
19```python
20import logging, sys
21 
22handler = logging.StreamHandler(stream=sys.stdout)
23handler.setFormatter(logging.Formatter("%(asctime)s | %(threadName)s | %(levelname)s | %(name)s | %(message)s"))
24logger = logging.getLogger('azure.servicebus')
25logger.setLevel(logging.DEBUG)
26logger.addHandler(handler)
27 
28# Enable AMQP frame tracing
29from azure.servicebus import ServiceBusClient
30client = ServiceBusClient(..., logging_enable=True)
31```
32 
33## AutoLockRenewer
34 
35```python
36from azure.servicebus import AutoLockRenewer
37 
38renewer = AutoLockRenewer()
39with receiver:
40    for message in receiver.receive_messages(max_message_count=10):
41        renewer.register(receiver, message, max_lock_renewal_duration=300)
42        # process message
43        receiver.complete_message(message)
44```
45 
46## Key Issues
47 
48- **Mixing sync/async**: Don't use `time.sleep()` in async code; use `await asyncio.sleep()`.
49- **Dead letter debugging**: Use `sub_queue=ServiceBusSubQueue.DEAD_LETTER` to inspect `dead_letter_reason` and `dead_letter_error_description`.
50- **Always close clients**: Use `with` statement or call `close()` to avoid connection leaks.
51