When we get a schema of a topic by api return Connection timed out

My request:
```
curl http://xxx.xxx.xxx.xxx:8080/admin/v2/schemas/Test/test/test_topic/schema
```
Sometimes,the broker returns SchemaInfo in resp.But most of the time the broker returns "Connection timed out"

Start by reproducing the curl request against the admin schema API and compare successful responses with the connection-timeout cases. Review the broker-side handling of this schema endpoint and its logs; done means the timeout cause is identified and the endpoint behavior is reliably corrected or clearly diagnosed.

Written by the indexing model from the issue text.