[KAFKA-9984] Should fail the subscription when pattern is empty

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.6.0
• Component/s: consumer
• Assignee: HaiyuanZhao
• Reporter: Boyang Chen
• Created: 13/May/20 01:29
• Updated: 14/May/20 21:19
• Resolved: 14/May/20 21:18

Description

We have seen a case where the consumer subscribes to an empty string pattern:
```

[Consumer ...  ] Subscribed to pattern:  ''

```

which doesn't make any sense and usually indicate a configuration error. The `consumer.subscribe(pattern)` call should fail with illegal argument for this case.

Issue Links

• links to: GitHub Pull Request #8665