hibernate/hibernate-orm · error · IllegalArgumentException

Region name [{}] referred to a query result region, not a do

Error message

Region name [{}] referred to a query result region, not a domain data region

What it means

The statistics API splits cache regions into domain-data regions (entity/collection data) and query-result regions. instantiateCacheRegionStatistics looks the name up and, when the Region is a QueryResultsRegion, refuses it with an IllegalArgumentException — query-result region counters must be read through the query-results path (instantiateCacheRegionStatsForQueryResults), which backs Statistics#getQueryRegionStatistics.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/stat/internal/StatisticsImpl.java:1018

	private CollectionStatisticsImpl instantiateCollectionStatistics(final String role) {
		return new CollectionStatisticsImpl( metamodel.getCollectionDescriptor( role ) );
	}

	private NaturalIdStatisticsImpl instantiateNaturalStatistics(final String entityName) {
		final EntityPersister entityDescriptor = metamodel.getEntityDescriptor( entityName );
		if ( !entityDescriptor.hasNaturalIdentifier() ) {
			throw new IllegalArgumentException( "Given entity [" + entityName + "] does not define natural-id" );
		}
		return new NaturalIdStatisticsImpl( entityDescriptor );
	}

	private CacheRegionStatisticsImpl instantiateCacheRegionStatistics(final String regionName) {
		final Region region = cache.getRegion( regionName );
		if ( region == null ) {
			throw new IllegalArgumentException( "Unknown cache region : " + regionName );
		}
		if ( region instanceof QueryResultsRegion ) {
			throw new IllegalArgumentException(
					"Region name [" + regionName + "] referred to a query result region, not a domain data region"
			);
		}
		return new CacheRegionStatisticsImpl( region );
	}

	private CacheRegionStatisticsImpl instantiateCacheRegionStatsForQueryResults(final String regionName) {
		return new CacheRegionStatisticsImpl( cache.getQueryResultsCache( regionName ).getRegion() );
	}

	private @Nullable CacheRegionStatisticsImpl createCacheRegionStatistics(final String regionName) {
		Region region = cache.getRegion( regionName );
		if ( region == null ) {
			if ( !queryCacheEnabled ) {
				return null;
			}
			// this is the pre-5.3 behavior.  and since this is a pre-5.3 method it should behave consistently
			// NOTE that this method is deprecated

View on GitHub (pinned to fad1729dce)

Solutions

Call statistics.getQueryRegionStatistics(regionName) for query-result regions; keep getDomainDataRegionStatistics for entity/collection regions.
Route by name: keep query-cache region names (default-query-results-region and any named query caches) in a separate list and dispatch to the query API.

Example fix

// before
CacheRegionStatistics s = statistics.getDomainDataRegionStatistics("default-query-results-region");
// IllegalArgumentException: query result region

// after
CacheRegionStatistics s = statistics.getQueryRegionStatistics("default-query-results-region");

Defensive patterns

Strategy: validation

Validate before calling

Set<String> queryRegions = Set.of("default-query-results-region"); // + any named query caches
CacheRegionStatistics s = queryRegions.contains(regionName)
        ? statistics.getQueryRegionStatistics(regionName)
        : statistics.getDomainDataRegionStatistics(regionName);

Try / catch

try {
    s = statistics.getDomainDataRegionStatistics(regionName);
} catch (IllegalArgumentException e) {
    // may be a query-result region — retry via the query path
    s = statistics.getQueryRegionStatistics(regionName);
}

Prevention

Treat domain-data and query-result regions as separate lists in monitoring config.
Name explicit regions with @Cache(region=...) and named query caches so kinds are obvious.
Never feed an unfiltered getSecondLevelCacheRegionNames() list into the domain-data accessor.

When it happens

Trigger: Passing a query-results region name (the default query results region, e.g. default-query-results-region, or a named query cache's region) to getDomainDataRegionStatistics; the instanceof QueryResultsRegion check fires and the call is rejected as a wrong region kind.

Common situations: A dashboard iterates every name from getSecondLevelCacheRegionNames() and routes them all into the domain-data accessor; entity-cache and query-cache names mixed in one configuration list; copy-pasting the domain call for the query cache.

Related errors

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/b8fa506e16aea0c3. Report an issue: GitHub.