[KUDU-2600] Java client: improve error message when trying to connect to the web instead of RPC port

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.7.0
• Component/s: client, java
• Labels: beginner
• Assignee: Unassigned
• Reporter: Alexey Serbin
• Created: 05/Oct/18 18:45
• Updated: 03/Jun/20 03:23

Description

When using Kudu Java client and specifying wrong RPC port, error messages look like the following:

org.apache.kudu.client.NoLeaderFoundException: Master config (<ip0>,<ip1>,<ip2>) has no leader. Exceptions received: org.apache.kudu.client.RecoverableException: connection disconnected,org.apache.kudu.client.RecoverableException: connection disconnected,org.apache.kudu.client.RecoverableException: connection disconnected no leader error

It would be nice to make the error message more actionable in that case. E.g., if using Kudu C++ client the error message would be more actionable, containing the following:

... received invalid RPC message which appears to be an HTTP response. Verify that you have specified a valid RPC port and not an HTTP port.

The relevant piece of the C++ code for that is in src/kudu/rpc/blocking_ops.cc, function ReceiveFramedMessageBlocking().