apache/pinot

`SchemaUtils` Doesn't Show the Actual Reason for Validation Failure

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#14787 opened on Jan 9, 2025

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 (3 comments) (0 reactions) (0 assignees)Java (4,937 stars) (1,234 forks)batch import
buggood first issue

Description

Often when our customers try to deploy, Pinot returns Schema is incompatible with tableConfig with no details about the root-cause. We should try to return the exact reason why the Schema validation had failed.

https://github.com/apache/pinot/blob/6a8bdb5e5e691381cda5122b03c6c3fd7b6fd265/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/SchemaUtils.java#L170-L181

Contributor guide

Tech stack
java
Domain
backenddatabase
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Javabasic understanding of schema validation
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
The issue is to improve error messages in SchemaUtils.java when schema validation fails. Locate the validation method at line 170-181 and modify it to capture the specific reason for failure (e.g., why the schema is incompatible with tableConfig). Consider using exceptions or validation result objects to propagate the reason. Check if there are any existing tests for this validation to understand expected behavior. The fix is localized and should not require cross module changes.