code: /*
   * 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.skywalking.oap.server.telemetry.api;
  
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.oap.server.library.util.HealthChecker;
  
  /**
   * HealthCheckMetrics intends to record health status.
   */
  @Slf4j
  public class HealthCheckMetrics implements HealthChecker {
      private final GaugeMetrics metrics;
  
      public HealthCheckMetrics(GaugeMetrics metrics) {
          this.metrics = metrics;
          // The initial status is unhealthy with -1 code.
          metrics.setValue(-1);
      }
  
      @Override
      public void health() {
          metrics.setValue(0);
      }
  
      @Override
      public void unHealth(Throwable t) {
          log.error("Health check fails", t);
          metrics.setValue(1);
      }
  
      @Override
      public void unHealth(String reason) {
          log.warn("Health check fails. reason: {}", reason);
          metrics.setValue(1);
      }
  }
  