SchemaUtils Doesn't Show the Actual Reason for Validation Failure

[ankitsultana]

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.

pinot/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/SchemaUtils.java

Lines 170 to 181 in 6a8bdb5

	/**
	* Validates that the schema is compatible with the given table config
	*/
	private static void validateCompatibilityWithTableConfig(Schema schema, TableConfig tableConfig) {
	try {
	TableConfigUtils.validate(tableConfig, schema);
	} catch (Exception e) {
	throw new IllegalStateException(
	"Schema is incompatible with tableConfig with name: " + tableConfig.getTableName() + " and type: "
	+ tableConfig.getTableType(), e);
	}
	}

[cutiepie-10]

Hi @ankitsultana,
I went through the code. The validation of the schema occurs in the TableConfigUtils.java done by some Preconditions.checkState which is thrown to validateCompatibilityWithTableConfig() and then to validate and then to the PinotSchemaRestletResource.validateInternalSchema, finally this method throws the exception.

According to me, the error and its cause is being provided in the stackTrace.

[ChavdaDhvani]

Hi @ankitsultana,
I reviewed the code, and from my understanding, schema validation occurs in TableConfigUtils.java using Preconditions.checkState. This is then passed to validateCompatibilityWithTableConfig(), which eventually throws the exception in PinotSchemaRestletResource.validateInternalSchema.
I believe the stack trace already provides the error cause, but adding more detailed information in the exception message could make it easier for users to identify the root cause quickly.
What do you think about this?
Thanks!