content: /*
   * 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.cassandra.service;
  
  import org.apache.cassandra.config.StartupChecksOptions;
  import org.apache.cassandra.exceptions.StartupException;
  import org.apache.cassandra.service.StartupChecks.StartupCheckType;
  
  /**
   * A test to determine if the system is in a valid state to start up.
   * Some implementations may not actually halt startup, but provide
   * information or advice on tuning and non-fatal environmental issues (e.g. like
   * checking for and warning about suboptimal JVM settings).
   * Other checks may indicate that the system is not in a correct state to be started.
   * Examples include missing or unaccessible data directories, unreadable sstables and
   * misconfiguration of cluster_name in cassandra.yaml.
   *
   * The StartupChecks class manages a collection of these tests, which it executes
   * right at the beginning of the server setup process.
   */
  public interface StartupCheck
  {
      /**
       * Run some test to determine whether the system is safe to be started
       * In the case where a test determines it is not safe to proceed, the
       * test should log a message regarding the reason for the failure and
       * ideally the steps required to remedy the problem.
       *
       * @param startupChecksOptions all options from descriptor
       * @throws org.apache.cassandra.exceptions.StartupException if the test determines
       * that the environement or system is not in a safe state to startup
       */
      void execute(StartupChecksOptions startupChecksOptions) throws StartupException;
  
      /**
       *
       * @return type of this startup check for configuration retrieval
       */
      default StartupCheckType getStartupCheckType()
      {
          return StartupCheckType.non_configurable_check;
      }
  
      /**
       * Post-hook after all startup checks succeeded.
       *
       * @param options startup check options from descriptor
       */
      default void postAction(StartupChecksOptions options)
      {
      }
  }
  