[CASSANDRA-16703] Exception thrown by custom QueryHandler constructor is ignored

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.0.25, 3.11.11, 4.0.1
• Component/s: Local/Startup and Shutdown
• Bug Category: Correctness
• Severity: Low
• Complexity: Low Hanging Fruit
• Discovered By: User Report
• Platform: All
• Since Version: 3.0.0

Source Control Link

https://github.com/apache/cassandra/commit/eadb171d5dfa9de3ecc6dce47515d48771fa98f9

Test and Documentation Plan

Started cassandra with invalid custom query handler, verified it fails and dies

Started cassandra with valid custom query handler, verified it started up and info log appeared

• Assignee: Zoltan Ersek
• Reporter: Francisco Bento

Authors

Zoltan Ersek

Reviewers

Benjamin Lerer, Brandon Williams, Francisco Bento

• Created: 28/May/21 15:15
• Updated: 07/Jul/21 20:13
• Resolved: 07/Jul/21 16:50

Description

When a exception is thrown during the instantiation of the cassandra.custom_query_handler_class, depending on the exception thrown cassandra will simply log an info message and proceed with the bootstraping with the standard QueryHandler as a fallback measure: https://github.com/apache/cassandra/blob/cassandra-3.11.10/src/java/org/apache/cassandra/service/ClientState.java#L107

The end-user will never know if the custom QueryHandler is actually registered or not, unless he notices the info message on the logs.

Ideally, the message should be logged as error and JVM should stop as it cannot proceed according with the user expected configuration.

Scenario:

In our scenario, we have a custom QueryHandler that receives specific configuration, and we throw a ConfigurationException at instantiation time in case of any invalid config value. It is expected that cassandra stop the bootstraping instead of skipping the QH.