| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.bookkeeper.bookie; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| import static org.apache.bookkeeper.util.BookKeeperConstants.BOOKIE_STATUS_FILENAME; |
| |
| import java.io.BufferedReader; |
| import java.io.BufferedWriter; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.io.OutputStreamWriter; |
| import java.util.List; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * The status object represents the current status of a bookie instance. |
| */ |
| public class BookieStatus { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(BookieStatus.class); |
| |
| static final int CURRENT_STATUS_LAYOUT_VERSION = 1; |
| |
| enum BookieMode { |
| READ_ONLY, |
| READ_WRITE |
| } |
| |
| private static final long INVALID_UPDATE_TIME = -1; |
| |
| private int layoutVersion; |
| private long lastUpdateTime; |
| private volatile BookieMode bookieMode; |
| |
| BookieStatus() { |
| this.bookieMode = BookieMode.READ_WRITE; |
| this.layoutVersion = CURRENT_STATUS_LAYOUT_VERSION; |
| this.lastUpdateTime = INVALID_UPDATE_TIME; |
| } |
| |
| private BookieMode getBookieMode() { |
| return bookieMode; |
| } |
| |
| public boolean isInWritable() { |
| return bookieMode.equals(BookieMode.READ_WRITE); |
| } |
| |
| synchronized boolean setToWritableMode() { |
| if (!bookieMode.equals(BookieMode.READ_WRITE)) { |
| bookieMode = BookieMode.READ_WRITE; |
| this.lastUpdateTime = System.currentTimeMillis(); |
| return true; |
| } |
| return false; |
| } |
| |
| boolean isInReadOnlyMode() { |
| return bookieMode.equals(BookieMode.READ_ONLY); |
| } |
| |
| synchronized boolean setToReadOnlyMode() { |
| if (!bookieMode.equals(BookieMode.READ_ONLY)) { |
| bookieMode = BookieMode.READ_ONLY; |
| this.lastUpdateTime = System.currentTimeMillis(); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Write bookie status to multiple directories in best effort. |
| * |
| * @param directories list of directories to write to |
| * |
| */ |
| synchronized void writeToDirectories(List<File> directories) { |
| boolean success = false; |
| for (File dir : directories) { |
| try { |
| File statusFile = new File(dir, BOOKIE_STATUS_FILENAME); |
| writeToFile(statusFile, toString()); |
| success = true; |
| } catch (IOException e) { |
| LOG.warn("IOException while trying to write bookie status to directory {}." |
| + " This is fine if not all directories are failed.", dir); |
| } |
| } |
| if (success) { |
| LOG.info("Successfully persist bookie status {}", this.bookieMode); |
| } else { |
| LOG.warn("Failed to persist bookie status {}", this.bookieMode); |
| } |
| } |
| |
| /** |
| * Write content to the file. If file does not exist, it will create one. |
| * |
| * @param file file that you want to write to |
| * @param body content to write |
| * @throws IOException |
| */ |
| private static void writeToFile(File file, String body) throws IOException { |
| try (FileOutputStream fos = new FileOutputStream(file); |
| BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos, UTF_8))) { |
| bw.write(body); |
| } |
| } |
| |
| /** |
| * Read bookie status from the status files, and update the bookie status if read succeed. |
| * If a status file is not readable or not found, it will skip and try to read from the next file. |
| * |
| * @param directories list of directories that store the status file |
| */ |
| void readFromDirectories(List<File> directories) { |
| boolean success = false; |
| for (File dir : directories) { |
| File statusFile = new File(dir, BOOKIE_STATUS_FILENAME); |
| try { |
| BookieStatus status = readFromFile(statusFile); |
| if (null != status) { |
| synchronized (status) { |
| if (status.lastUpdateTime > this.lastUpdateTime) { |
| this.lastUpdateTime = status.lastUpdateTime; |
| this.layoutVersion = status.layoutVersion; |
| this.bookieMode = status.bookieMode; |
| success = true; |
| } |
| } |
| } |
| } catch (IOException e) { |
| LOG.warn("IOException while trying to read bookie status from directory {}." |
| + " This is fine if not all directories failed.", dir); |
| } catch (IllegalArgumentException e) { |
| LOG.warn("IllegalArgumentException while trying to read bookie status from directory {}." |
| + " This is fine if not all directories failed.", dir); |
| } |
| } |
| if (success) { |
| LOG.info("Successfully retrieve bookie status {} from disks.", getBookieMode()); |
| } else { |
| LOG.warn("Failed to retrieve bookie status from disks." |
| + " Fall back to current or default bookie status: {}", getBookieMode()); |
| } |
| } |
| |
| |
| /** |
| * Function to read the bookie status from a single file. |
| * |
| * @param file file to read from |
| * @return BookieStatus if not error, null if file not exist or any exception happens |
| * @throws IOException |
| */ |
| private BookieStatus readFromFile(File file) |
| throws IOException, IllegalArgumentException { |
| if (!file.exists()) { |
| return null; |
| } |
| |
| try (BufferedReader reader = new BufferedReader( |
| new InputStreamReader(new FileInputStream(file), UTF_8))) { |
| return parse(reader); |
| } |
| } |
| |
| /** |
| * Parse the bookie status object using appropriate layout version. |
| * |
| * @param reader |
| * @return BookieStatus if parse succeed, otherwise return null |
| * @throws IOException |
| */ |
| public BookieStatus parse(BufferedReader reader) |
| throws IOException, IllegalArgumentException { |
| BookieStatus status = new BookieStatus(); |
| String line = reader.readLine(); |
| if (line == null || line.trim().isEmpty()) { |
| LOG.debug("Empty line when parsing bookie status"); |
| return null; |
| } |
| String[] parts = line.split(","); |
| if (parts.length == 0) { |
| LOG.debug("Error in parsing bookie status: {}", line); |
| return null; |
| } |
| synchronized (status) { |
| status.layoutVersion = Integer.parseInt(parts[0].trim()); |
| if (status.layoutVersion == 1 && parts.length == 3) { |
| status.bookieMode = BookieMode.valueOf(parts[1]); |
| status.lastUpdateTime = Long.parseLong(parts[2].trim()); |
| return status; |
| } |
| } |
| return null; |
| |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder builder = new StringBuilder(); |
| builder.append(CURRENT_STATUS_LAYOUT_VERSION); |
| builder.append(","); |
| builder.append(getBookieMode()); |
| builder.append(","); |
| builder.append(System.currentTimeMillis()); |
| builder.append("\n"); |
| return builder.toString(); |
| } |
| |
| } |