/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.jena.fuseki.metrics;

import io.micrometer.core.instrument.MeterRegistry;
import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
import org.apache.jena.fuseki.servlets.HttpAction;
import org.apache.jena.fuseki.servlets.ServletOps;

public class SimpleMetricsProvider implements MetricsProvider {

    private MeterRegistry meterRegistry = new SimpleMeterRegistry();

    @Override
    public MeterRegistry getMeterRegistry() {
        return meterRegistry;
    }

    @Override
    public void scrape(HttpAction action) {
        ServletOps.errorNotImplemented( "SimpleMeterRegistry isn't scrapeable" );
    }

}

@@ -1058,16 +1058,51 @@
 vletOps;
+%0Aimport org.apache.jena.web.HttpSC;
 %0A%0Apublic
@@ -1408,28 +1408,86 @@
 Ops.
-errorNotImplemented(
+responseSendError(action.response, HttpSC.NOT_IMPLEMENTED_501,%0A               
  %22Si

Return 501 error properly in SimpleMetricsProvider