| /** |
| * 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.falcon.util; |
| |
| import org.apache.falcon.FalconException; |
| import org.apache.falcon.hadoop.HadoopClientFactory; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.IOException; |
| import java.util.Properties; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| /** |
| * Properties read during application startup. |
| */ |
| public final class StartupProperties extends ApplicationProperties { |
| |
| public static final String SAFEMODE_PROPERTY = "falcon.safeMode"; |
| private static final String SAFEMODE_FILE = ".safemode"; |
| private static final String CONFIGSTORE_PROPERTY = "config.store.uri"; |
| |
| private static FileSystem fileSystem; |
| private static Path storePath; |
| |
| private static final String PROPERTY_FILE = "startup.properties"; |
| private static final Logger LOG = LoggerFactory.getLogger(StartupProperties.class); |
| |
| private static final AtomicReference<StartupProperties> INSTANCE = |
| new AtomicReference<StartupProperties>(); |
| |
| private StartupProperties() throws FalconException { |
| super(); |
| resolveAlias(); |
| } |
| |
| @Override |
| protected String getPropertyFile() { |
| return PROPERTY_FILE; |
| } |
| |
| public static Properties get() { |
| try { |
| if (INSTANCE.get() == null) { |
| INSTANCE.compareAndSet(null, new StartupProperties()); |
| storePath = new Path((INSTANCE.get().getProperty(CONFIGSTORE_PROPERTY))); |
| fileSystem = HadoopClientFactory.get().createFalconFileSystem(storePath.toUri()); |
| } |
| return INSTANCE.get(); |
| } catch (FalconException e) { |
| throw new RuntimeException("Unable to read application startup properties", e); |
| } |
| } |
| |
| public static void createSafemodeFile() throws IOException { |
| Path safemodeFilePath = getSafemodeFilePath(); |
| if (!doesSafemodeFileExist()) { |
| boolean success = fileSystem.createNewFile(safemodeFilePath); |
| if (!success) { |
| LOG.error("Failed to create safemode file at {}", safemodeFilePath.toUri()); |
| throw new IOException("Failed to create safemode file at " + safemodeFilePath.toUri()); |
| } |
| } |
| INSTANCE.get().setProperty(SAFEMODE_PROPERTY, "true"); |
| } |
| |
| public static boolean deleteSafemodeFile() throws IOException { |
| INSTANCE.get().setProperty(SAFEMODE_PROPERTY, "false"); |
| return !doesSafemodeFileExist() || fileSystem.delete(getSafemodeFilePath(), true); |
| } |
| |
| public static boolean doesSafemodeFileExist() throws IOException { |
| return fileSystem.exists(getSafemodeFilePath()); |
| } |
| |
| private static Path getSafemodeFilePath() { |
| return new Path(storePath, SAFEMODE_FILE); |
| } |
| |
| public static boolean isServerInSafeMode() { |
| return Boolean.parseBoolean(StartupProperties.get().getProperty(StartupProperties.SAFEMODE_PROPERTY, "false")); |
| } |
| |
| } |