hadoop2.6.4【windows7】构建maven项目 系列2
准备windows版本的hadoop2.6.4
下载windows版本的hadoop2.6.4解压在本地
新建maven项目构建hadoop依赖
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.tangxin.hadoop.learn</groupId> <artifactId>hadoop-learn</artifactId> <version>1.0-SNAPSHOT</version> <properties> <hadoop.version>2.6.4</hadoop.version> </properties> <dependencies> <dependency> <groupId>org.apache.hadoop</groupId> <artifactId>hadoop-common</artifactId> <version>${hadoop.version}</version> </dependency> <dependency> <groupId>org.apache.hadoop</groupId> <artifactId>hadoop-hdfs</artifactId> <version>${hadoop.version}</version> </dependency> <dependency> <groupId>org.apache.hadoop</groupId> <artifactId>hadoop-client</artifactId> <version>${hadoop.version}</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <configuration> <archive> <manifest> <mainClass>org.conan.myhadoop.hdfs.WordCountMapReduce</mainClass> <addClasspath>true</addClasspath> <classpathPrefix>lib/</classpathPrefix> </manifest> </archive> <classesDirectory> </classesDirectory> </configuration> </plugin> </plugins> </build> </project>
重写hadoop的NativeIO.java类
/** * 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.hadoop.io.nativeio; import java.io.File; import java.io.FileDescriptor; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.RandomAccessFile; import java.lang.reflect.Field; import java.nio.ByteBuffer; import java.nio.MappedByteBuffer; import java.nio.channels.FileChannel; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.CommonConfigurationKeys; import org.apache.hadoop.fs.HardLink; import org.apache.hadoop.io.IOUtils; import org.apache.hadoop.io.SecureIOUtils.AlreadyExistsException; import org.apache.hadoop.util.NativeCodeLoader; import org.apache.hadoop.util.Shell; import org.apache.hadoop.util.PerformanceAdvisory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import sun.misc.Unsafe; import com.google.common.annotations.VisibleForTesting; /** * JNI wrappers for various native IO-related calls not available in Java. * These functions should generally be used alongside a fallback to another * more portable mechanism. */ @InterfaceAudience.Private @InterfaceStability.Unstable public class NativeIO { public static class POSIX { // Flags for open() call from bits/fcntl.h public static final int O_RDONLY = 00; public static final int O_WRONLY = 01; public static final int O_RDWR = 02; public static final int O_CREAT = 0100; public static final int O_EXCL = 0200; public static final int O_NOCTTY = 0400; public static final int O_TRUNC = 01000; public static final int O_APPEND = 02000; public static final int O_NONBLOCK = 04000; public static final int O_SYNC = 010000; public static final int O_ASYNC = 020000; public static final int O_FSYNC = O_SYNC; public static final int O_NDELAY = O_NONBLOCK; // Flags for posix_fadvise() from bits/fcntl.h /* No further special treatment. */ public static final int POSIX_FADV_NORMAL = 0; /* Expect random page references. */ public static final int POSIX_FADV_RANDOM = 1; /* Expect sequential page references. */ public static final int POSIX_FADV_SEQUENTIAL = 2; /* Will need these pages. */ public static final int POSIX_FADV_WILLNEED = 3; /* Don't need these pages. */ public static final int POSIX_FADV_DONTNEED = 4; /* Data will be accessed once. */ public static final int POSIX_FADV_NOREUSE = 5; /* Wait upon writeout of all pages in the range before performing the write. */ public static final int SYNC_FILE_RANGE_WAIT_BEFORE = 1; /* Initiate writeout of all those dirty pages in the range which are not presently under writeback. */ public static final int SYNC_FILE_RANGE_WRITE = 2; /* Wait upon writeout of all pages in the range after performing the write. */ public static final int SYNC_FILE_RANGE_WAIT_AFTER = 4; private static final Log LOG = LogFactory.getLog(NativeIO.class); private static boolean nativeLoaded = false; private static boolean fadvisePossible = true; private static boolean syncFileRangePossible = true; static final String WORKAROUND_NON_THREADSAFE_CALLS_KEY = "hadoop.workaround.non.threadsafe.getpwuid"; static final boolean WORKAROUND_NON_THREADSAFE_CALLS_DEFAULT = true; private static long cacheTimeout = -1; private static CacheManipulator cacheManipulator = new CacheManipulator(); public static CacheManipulator getCacheManipulator() { return cacheManipulator; } public static void setCacheManipulator(CacheManipulator cacheManipulator) { POSIX.cacheManipulator = cacheManipulator; } /** * Used to manipulate the operating system cache. */ @VisibleForTesting public static class CacheManipulator { public void mlock(String identifier, ByteBuffer buffer, long len) throws IOException { POSIX.mlock(buffer, len); } public long getMemlockLimit() { return NativeIO.getMemlockLimit(); } public long getOperatingSystemPageSize() { return NativeIO.getOperatingSystemPageSize(); } public void posixFadviseIfPossible(String identifier, FileDescriptor fd, long offset, long len, int flags) throws NativeIOException { NativeIO.POSIX.posixFadviseIfPossible(identifier, fd, offset, len, flags); } public boolean verifyCanMlock() { return NativeIO.isAvailable(); } } /** * A CacheManipulator used for testing which does not actually call mlock. * This allows many tests to be run even when the operating system does not * allow mlock, or only allows limited mlocking. */ @VisibleForTesting public static class NoMlockCacheManipulator extends CacheManipulator { public void mlock(String identifier, ByteBuffer buffer, long len) throws IOException { LOG.info("mlocking " + identifier); } public long getMemlockLimit() { return 1125899906842624L; } public long getOperatingSystemPageSize() { return 4096; } public boolean verifyCanMlock() { return true; } } static { if (NativeCodeLoader.isNativeCodeLoaded()) { try { Configuration conf = new Configuration(); workaroundNonThreadSafePasswdCalls = conf.getBoolean( WORKAROUND_NON_THREADSAFE_CALLS_KEY, WORKAROUND_NON_THREADSAFE_CALLS_DEFAULT); initNative(); nativeLoaded = true; cacheTimeout = conf.getLong( CommonConfigurationKeys.HADOOP_SECURITY_UID_NAME_CACHE_TIMEOUT_KEY, CommonConfigurationKeys.HADOOP_SECURITY_UID_NAME_CACHE_TIMEOUT_DEFAULT) * 1000; LOG.debug("Initialized cache for IDs to User/Group mapping with a " + " cache timeout of " + cacheTimeout/1000 + " seconds."); } catch (Throwable t) { // This can happen if the user has an older version of libhadoop.so // installed - in this case we can continue without native IO // after warning PerformanceAdvisory.LOG.debug("Unable to initialize NativeIO libraries", t); } } } /** * Return true if the JNI-based native IO extensions are available. */ public static boolean isAvailable() { return NativeCodeLoader.isNativeCodeLoaded() && nativeLoaded; } private static void assertCodeLoaded() throws IOException { if (!isAvailable()) { throw new IOException("NativeIO was not loaded"); } } /** Wrapper around open(2) */ public static native FileDescriptor open(String path, int flags, int mode) throws IOException; /** Wrapper around fstat(2) */ private static native Stat fstat(FileDescriptor fd) throws IOException; /** Native chmod implementation. On UNIX, it is a wrapper around chmod(2) */ private static native void chmodImpl(String path, int mode) throws IOException; public static void chmod(String path, int mode) throws IOException { if (!Shell.WINDOWS) { chmodImpl(path, mode); } else { try { chmodImpl(path, mode); } catch (NativeIOException nioe) { if (nioe.getErrorCode() == 3) { throw new NativeIOException("No such file or directory", Errno.ENOENT); } else { LOG.warn(String.format("NativeIO.chmod error (%d): %s", nioe.getErrorCode(), nioe.getMessage())); throw new NativeIOException("Unknown error", Errno.UNKNOWN); } } } } /** Wrapper around posix_fadvise(2) */ static native void posix_fadvise( FileDescriptor fd, long offset, long len, int flags) throws NativeIOException; /** Wrapper around sync_file_range(2) */ static native void sync_file_range( FileDescriptor fd, long offset, long nbytes, int flags) throws NativeIOException; /** * Call posix_fadvise on the given file descriptor. See the manpage * for this syscall for more information. On systems where this * call is not available, does nothing. * * @throws NativeIOException if there is an error with the syscall */ static void posixFadviseIfPossible(String identifier, FileDescriptor fd, long offset, long len, int flags) throws NativeIOException { if (nativeLoaded && fadvisePossible) { try { posix_fadvise(fd, offset, len, flags); } catch (UnsupportedOperationException uoe) { fadvisePossible = false; } catch (UnsatisfiedLinkError ule) { fadvisePossible = false; } } } /** * Call sync_file_range on the given file descriptor. See the manpage * for this syscall for more information. On systems where this * call is not available, does nothing. * * @throws NativeIOException if there is an error with the syscall */ public static void syncFileRangeIfPossible( FileDescriptor fd, long offset, long nbytes, int flags) throws NativeIOException { if (nativeLoaded && syncFileRangePossible) { try { sync_file_range(fd, offset, nbytes, flags); } catch (UnsupportedOperationException uoe) { syncFileRangePossible = false; } catch (UnsatisfiedLinkError ule) { syncFileRangePossible = false; } } } static native void mlock_native( ByteBuffer buffer, long len) throws NativeIOException; /** * Locks the provided direct ByteBuffer into memory, preventing it from * swapping out. After a buffer is locked, future accesses will not incur * a page fault. * * See the mlock(2) man page for more information. * * @throws NativeIOException */ static void mlock(ByteBuffer buffer, long len) throws IOException { assertCodeLoaded(); if (!buffer.isDirect()) { throw new IOException("Cannot mlock a non-direct ByteBuffer"); } mlock_native(buffer, len); } /** * Unmaps the block from memory. See munmap(2). * * There isn't any portable way to unmap a memory region in Java. * So we use the sun.nio method here. * Note that unmapping a memory region could cause crashes if code * continues to reference the unmapped code. However, if we don't * manually unmap the memory, we are dependent on the finalizer to * do it, and we have no idea when the finalizer will run. * * @param buffer The buffer to unmap. */ public static void munmap(MappedByteBuffer buffer) { if (buffer instanceof sun.nio.ch.DirectBuffer) { sun.misc.Cleaner cleaner = ((sun.nio.ch.DirectBuffer)buffer).cleaner(); cleaner.clean(); } } /** Linux only methods used for getOwner() implementation */ private static native long getUIDforFDOwnerforOwner(FileDescriptor fd) throws IOException; private static native String getUserName(long uid) throws IOException; /** * Result type of the fstat call */ public static class Stat { private int ownerId, groupId; private String owner, group; private int mode; // Mode constants public static final int S_IFMT = 0170000; /* type of file */ public static final int S_IFIFO = 0010000; /* named pipe (fifo) */ public static final int S_IFCHR = 0020000; /* character special */ public static final int S_IFDIR = 0040000; /* directory */ public static final int S_IFBLK = 0060000; /* block special */ public static final int S_IFREG = 0100000; /* regular */ public static final int S_IFLNK = 0120000; /* symbolic link */ public static final int S_IFSOCK = 0140000; /* socket */ public static final int S_IFWHT = 0160000; /* whiteout */ public static final int S_ISUID = 0004000; /* set user id on execution */ public static final int S_ISGID = 0002000; /* set group id on execution */ public static final int S_ISVTX = 0001000; /* save swapped text even after use */ public static final int S_IRUSR = 0000400; /* read permission, owner */ public static final int S_IWUSR = 0000200; /* write permission, owner */ public static final int S_IXUSR = 0000100; /* execute/search permission, owner */ Stat(int ownerId, int groupId, int mode) { this.ownerId = ownerId; this.groupId = groupId; this.mode = mode; } Stat(String owner, String group, int mode) { if (!Shell.WINDOWS) { this.owner = owner; } else { this.owner = stripDomain(owner); } if (!Shell.WINDOWS) { this.group = group; } else { this.group = stripDomain(group); } this.mode = mode; } @Override public String toString() { return "Stat(owner='" + owner + "', group='" + group + "'" + ", mode=" + mode + ")"; } public String getOwner() { return owner; } public String getGroup() { return group; } public int getMode() { return mode; } } /** * Returns the file stat for a file descriptor. * * @param fd file descriptor. * @return the file descriptor file stat. * @throws IOException thrown if there was an IO error while obtaining the file stat. */ public static Stat getFstat(FileDescriptor fd) throws IOException { Stat stat = null; if (!Shell.WINDOWS) { stat = fstat(fd); stat.owner = getName(IdCache.USER, stat.ownerId); stat.group = getName(IdCache.GROUP, stat.groupId); } else { try { stat = fstat(fd); } catch (NativeIOException nioe) { if (nioe.getErrorCode() == 6) { throw new NativeIOException("The handle is invalid.", Errno.EBADF); } else { LOG.warn(String.format("NativeIO.getFstat error (%d): %s", nioe.getErrorCode(), nioe.getMessage())); throw new NativeIOException("Unknown error", Errno.UNKNOWN); } } } return stat; } private static String getName(IdCache domain, int id) throws IOException { Map<Integer, CachedName> idNameCache = (domain == IdCache.USER) ? USER_ID_NAME_CACHE : GROUP_ID_NAME_CACHE; String name; CachedName cachedName = idNameCache.get(id); long now = System.currentTimeMillis(); if (cachedName != null && (cachedName.timestamp + cacheTimeout) > now) { name = cachedName.name; } else { name = (domain == IdCache.USER) ? getUserName(id) : getGroupName(id); if (LOG.isDebugEnabled()) { String type = (domain == IdCache.USER) ? "UserName" : "GroupName"; LOG.debug("Got " + type + " " + name + " for ID " + id + " from the native implementation"); } cachedName = new CachedName(name, now); idNameCache.put(id, cachedName); } return name; } static native String getUserName(int uid) throws IOException; static native String getGroupName(int uid) throws IOException; private static class CachedName { final long timestamp; final String name; public CachedName(String name, long timestamp) { this.name = name; this.timestamp = timestamp; } } private static final Map<Integer, CachedName> USER_ID_NAME_CACHE = new ConcurrentHashMap<Integer, CachedName>(); private static final Map<Integer, CachedName> GROUP_ID_NAME_CACHE = new ConcurrentHashMap<Integer, CachedName>(); private enum IdCache { USER, GROUP } public final static int MMAP_PROT_READ = 0x1; public final static int MMAP_PROT_WRITE = 0x2; public final static int MMAP_PROT_EXEC = 0x4; public static native long mmap(FileDescriptor fd, int prot, boolean shared, long length) throws IOException; public static native void munmap(long addr, long length) throws IOException; } private static boolean workaroundNonThreadSafePasswdCalls = false; public static class Windows { // Flags for CreateFile() call on Windows public static final long GENERIC_READ = 0x80000000L; public static final long GENERIC_WRITE = 0x40000000L; public static final long FILE_SHARE_READ = 0x00000001L; public static final long FILE_SHARE_WRITE = 0x00000002L; public static final long FILE_SHARE_DELETE = 0x00000004L; public static final long CREATE_NEW = 1; public static final long CREATE_ALWAYS = 2; public static final long OPEN_EXISTING = 3; public static final long OPEN_ALWAYS = 4; public static final long TRUNCATE_EXISTING = 5; public static final long FILE_BEGIN = 0; public static final long FILE_CURRENT = 1; public static final long FILE_END = 2; public static final long FILE_ATTRIBUTE_NORMAL = 0x00000080L; /** Wrapper around CreateFile() on Windows */ public static native FileDescriptor createFile(String path, long desiredAccess, long shareMode, long creationDisposition) throws IOException; /** Wrapper around SetFilePointer() on Windows */ public static native long setFilePointer(FileDescriptor fd, long distanceToMove, long moveMethod) throws IOException; /** Windows only methods used for getOwner() implementation */ private static native String getOwner(FileDescriptor fd) throws IOException; /** Supported list of Windows access right flags */ public static enum AccessRight { ACCESS_READ (0x0001), // FILE_READ_DATA ACCESS_WRITE (0x0002), // FILE_WRITE_DATA ACCESS_EXECUTE (0x0020); // FILE_EXECUTE private final int accessRight; AccessRight(int access) { accessRight = access; } public int accessRight() { return accessRight; } }; /** Windows only method used to check if the current process has requested * access rights on the given path. */ private static native boolean access0(String path, int requestedAccess); /** * Checks whether the current process has desired access rights on * the given path. * * Longer term this native function can be substituted with JDK7 * function Files#isReadable, isWritable, isExecutable. * * @param path input path * @param desiredAccess ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE * @return true if access is allowed * @throws IOException I/O exception on error */ public static boolean access(String path, AccessRight desiredAccess) throws IOException { return true; //return access0(path, desiredAccess.accessRight()); } /** * Extends both the minimum and maximum working set size of the current * process. This method gets the current minimum and maximum working set * size, adds the requested amount to each and then sets the minimum and * maximum working set size to the new values. Controlling the working set * size of the process also controls the amount of memory it can lock. * * @param delta amount to increment minimum and maximum working set size * @throws IOException for any error * @see POSIX#mlock(ByteBuffer, long) */ public static native void extendWorkingSetSize(long delta) throws IOException; static { if (NativeCodeLoader.isNativeCodeLoaded()) { try { initNative(); nativeLoaded = true; } catch (Throwable t) { // This can happen if the user has an older version of libhadoop.so // installed - in this case we can continue without native IO // after warning PerformanceAdvisory.LOG.debug("Unable to initialize NativeIO libraries", t); } } } } private static final Log LOG = LogFactory.getLog(NativeIO.class); private static boolean nativeLoaded = false; static { if (NativeCodeLoader.isNativeCodeLoaded()) { try { initNative(); nativeLoaded = true; } catch (Throwable t) { // This can happen if the user has an older version of libhadoop.so // installed - in this case we can continue without native IO // after warning PerformanceAdvisory.LOG.debug("Unable to initialize NativeIO libraries", t); } } } /** * Return true if the JNI-based native IO extensions are available. */ public static boolean isAvailable() { return NativeCodeLoader.isNativeCodeLoaded() && nativeLoaded; } /** Initialize the JNI method ID and class ID cache */ private static native void initNative(); /** * Get the maximum number of bytes that can be locked into memory at any * given point. * * @return 0 if no bytes can be locked into memory; * Long.MAX_VALUE if there is no limit; * The number of bytes that can be locked into memory otherwise. */ static long getMemlockLimit() { return isAvailable() ? getMemlockLimit0() : 0; } private static native long getMemlockLimit0(); /** * @return the operating system's page size. */ static long getOperatingSystemPageSize() { try { Field f = Unsafe.class.getDeclaredField("theUnsafe"); f.setAccessible(true); Unsafe unsafe = (Unsafe)f.get(null); return unsafe.pageSize(); } catch (Throwable e) { LOG.warn("Unable to get operating system page size. Guessing 4096.", e); return 4096; } } private static class CachedUid { final long timestamp; final String username; public CachedUid(String username, long timestamp) { this.timestamp = timestamp; this.username = username; } } private static final Map<Long, CachedUid> uidCache = new ConcurrentHashMap<Long, CachedUid>(); private static long cacheTimeout; private static boolean initialized = false; /** * The Windows logon name has two part, NetBIOS domain name and * user account name, of the format DOMAIN\UserName. This method * will remove the domain part of the full logon name. * * @param Fthe full principal name containing the domain * @return name with domain removed */ private static String stripDomain(String name) { int i = name.indexOf('\\'); if (i != -1) name = name.substring(i + 1); return name; } public static String getOwner(FileDescriptor fd) throws IOException { ensureInitialized(); if (Shell.WINDOWS) { String owner = Windows.getOwner(fd); owner = stripDomain(owner); return owner; } else { long uid = POSIX.getUIDforFDOwnerforOwner(fd); CachedUid cUid = uidCache.get(uid); long now = System.currentTimeMillis(); if (cUid != null && (cUid.timestamp + cacheTimeout) > now) { return cUid.username; } String user = POSIX.getUserName(uid); LOG.info("Got UserName " + user + " for UID " + uid + " from the native implementation"); cUid = new CachedUid(user, now); uidCache.put(uid, cUid); return user; } } /** * Create a FileInputStream that shares delete permission on the * file opened, i.e. other process can delete the file the * FileInputStream is reading. Only Windows implementation uses * the native interface. */ public static FileInputStream getShareDeleteFileInputStream(File f) throws IOException { if (!Shell.WINDOWS) { // On Linux the default FileInputStream shares delete permission // on the file opened. // return new FileInputStream(f); } else { // Use Windows native interface to create a FileInputStream that // shares delete permission on the file opened. // FileDescriptor fd = Windows.createFile( f.getAbsolutePath(), Windows.GENERIC_READ, Windows.FILE_SHARE_READ | Windows.FILE_SHARE_WRITE | Windows.FILE_SHARE_DELETE, Windows.OPEN_EXISTING); return new FileInputStream(fd); } } /** * Create a FileInputStream that shares delete permission on the * file opened at a given offset, i.e. other process can delete * the file the FileInputStream is reading. Only Windows implementation * uses the native interface. */ public static FileInputStream getShareDeleteFileInputStream(File f, long seekOffset) throws IOException { if (!Shell.WINDOWS) { RandomAccessFile rf = new RandomAccessFile(f, "r"); if (seekOffset > 0) { rf.seek(seekOffset); } return new FileInputStream(rf.getFD()); } else { // Use Windows native interface to create a FileInputStream that // shares delete permission on the file opened, and set it to the // given offset. // FileDescriptor fd = NativeIO.Windows.createFile( f.getAbsolutePath(), NativeIO.Windows.GENERIC_READ, NativeIO.Windows.FILE_SHARE_READ | NativeIO.Windows.FILE_SHARE_WRITE | NativeIO.Windows.FILE_SHARE_DELETE, NativeIO.Windows.OPEN_EXISTING); if (seekOffset > 0) NativeIO.Windows.setFilePointer(fd, seekOffset, NativeIO.Windows.FILE_BEGIN); return new FileInputStream(fd); } } /** * Create the specified File for write access, ensuring that it does not exist. * @param f the file that we want to create * @param permissions we want to have on the file (if security is enabled) * * @throws AlreadyExistsException if the file already exists * @throws IOException if any other error occurred */ public static FileOutputStream getCreateForWriteFileOutputStream(File f, int permissions) throws IOException { if (!Shell.WINDOWS) { // Use the native wrapper around open(2) try { FileDescriptor fd = NativeIO.POSIX.open(f.getAbsolutePath(), NativeIO.POSIX.O_WRONLY | NativeIO.POSIX.O_CREAT | NativeIO.POSIX.O_EXCL, permissions); return new FileOutputStream(fd); } catch (NativeIOException nioe) { if (nioe.getErrno() == Errno.EEXIST) { throw new AlreadyExistsException(nioe); } throw nioe; } } else { // Use the Windows native APIs to create equivalent FileOutputStream try { FileDescriptor fd = NativeIO.Windows.createFile(f.getCanonicalPath(), NativeIO.Windows.GENERIC_WRITE, NativeIO.Windows.FILE_SHARE_DELETE | NativeIO.Windows.FILE_SHARE_READ | NativeIO.Windows.FILE_SHARE_WRITE, NativeIO.Windows.CREATE_NEW); NativeIO.POSIX.chmod(f.getCanonicalPath(), permissions); return new FileOutputStream(fd); } catch (NativeIOException nioe) { if (nioe.getErrorCode() == 80) { // ERROR_FILE_EXISTS // 80 (0x50) // The file exists throw new AlreadyExistsException(nioe); } throw nioe; } } } private synchronized static void ensureInitialized() { if (!initialized) { cacheTimeout = new Configuration().getLong("hadoop.security.uid.cache.secs", 4*60*60) * 1000; LOG.info("Initialized cache for UID to User mapping with a cache" + " timeout of " + cacheTimeout/1000 + " seconds."); initialized = true; } } /** * A version of renameTo that throws a descriptive exception when it fails. * * @param src The source path * @param dst The destination path * * @throws NativeIOException On failure. */ public static void renameTo(File src, File dst) throws IOException { if (!nativeLoaded) { if (!src.renameTo(dst)) { throw new IOException("renameTo(src=" + src + ", dst=" + dst + ") failed."); } } else { renameTo0(src.getAbsolutePath(), dst.getAbsolutePath()); } } public static void link(File src, File dst) throws IOException { if (!nativeLoaded) { HardLink.createHardLink(src, dst); } else { link0(src.getAbsolutePath(), dst.getAbsolutePath()); } } /** * A version of renameTo that throws a descriptive exception when it fails. * * @param src The source path * @param dst The destination path * * @throws NativeIOException On failure. */ private static native void renameTo0(String src, String dst) throws NativeIOException; private static native void link0(String src, String dst) throws NativeIOException; /** * Unbuffered file copy from src to dst without tainting OS buffer cache * * In POSIX platform: * It uses FileChannel#transferTo() which internally attempts * unbuffered IO on OS with native sendfile64() support and falls back to * buffered IO otherwise. * * It minimizes the number of FileChannel#transferTo call by passing the the * src file size directly instead of a smaller size as the 3rd parameter. * This saves the number of sendfile64() system call when native sendfile64() * is supported. In the two fall back cases where sendfile is not supported, * FileChannle#transferTo already has its own batching of size 8 MB and 8 KB, * respectively. * * In Windows Platform: * It uses its own native wrapper of CopyFileEx with COPY_FILE_NO_BUFFERING * flag, which is supported on Windows Server 2008 and above. * * Ideally, we should use FileChannel#transferTo() across both POSIX and Windows * platform. Unfortunately, the wrapper(Java_sun_nio_ch_FileChannelImpl_transferTo0) * used by FileChannel#transferTo for unbuffered IO is not implemented on Windows. * Based on OpenJDK 6/7/8 source code, Java_sun_nio_ch_FileChannelImpl_transferTo0 * on Windows simply returns IOS_UNSUPPORTED. * * Note: This simple native wrapper does minimal parameter checking before copy and * consistency check (e.g., size) after copy. * It is recommended to use wrapper function like * the Storage#nativeCopyFileUnbuffered() function in hadoop-hdfs with pre/post copy * checks. * * @param src The source path * @param dst The destination path * @throws IOException */ public static void copyFileUnbuffered(File src, File dst) throws IOException { if (nativeLoaded && Shell.WINDOWS) { copyFileUnbuffered0(src.getAbsolutePath(), dst.getAbsolutePath()); } else { FileInputStream fis = null; FileOutputStream fos = null; FileChannel input = null; FileChannel output = null; try { fis = new FileInputStream(src); fos = new FileOutputStream(dst); input = fis.getChannel(); output = fos.getChannel(); long remaining = input.size(); long position = 0; long transferred = 0; while (remaining > 0) { transferred = input.transferTo(position, remaining, output); remaining -= transferred; position += transferred; } } finally { IOUtils.cleanup(LOG, output); IOUtils.cleanup(LOG, fos); IOUtils.cleanup(LOG, input); IOUtils.cleanup(LOG, fis); } } } private static native void copyFileUnbuffered0(String src, String dst) throws NativeIOException; }
创建WordCountMapReduce.java
package org.conan.myhadoop.hdfs; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; /** * Created by Administrator on 2017/8/16. */ public class WordCountMapReduce { public static void main(String[] args) throws Exception{ System.setProperty("hadoop.home.dir", "E:\\hadoop-2.6.4"); //System.setProperty("HADOOP_USER_NAME", "root"); //创建配置对象 Configuration conf = new Configuration(); //创建job对象 Job job = Job.getInstance(conf,"wordcount"); //设置运行job的主类 job.setJarByClass(WordCountMapReduce.class); //设置mapper类 job.setMapperClass(WordCountMapper.class); //设置reduce类 job.setReducerClass(WordCountReducer.class); //设置map输出的key value job.setMapOutputKeyClass(Text.class); job.setOutputValueClass(IntWritable.class); //设置reducer输出的key value job.setOutputKeyClass(Text.class); job.setOutputValueClass(IntWritable.class); //设置输入路径 //-rw-r--r--. 1 root root 24 Aug 21 23:34 words FileInputFormat.setInputPaths(job,new Path("hdfs://172.16.16.218:9000/input")); FileOutputFormat.setOutputPath(job,new Path("hdfs://172.16.16.218:9000/out07")); boolean b = job.waitForCompletion(true); if(!b){ System.err.println("This task has failed!!!"); }else{ System.out.println("This task has success!!!"); } } }
创建WordCountMapper.java
package org.conan.myhadoop.hdfs; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Mapper; import java.io.IOException; /** * Created by Administrator on 2017/8/16. */ public class WordCountMapper extends Mapper<LongWritable,Text,Text,IntWritable>{ @Override protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { //得到输入的每一行数据 hello a String line = value.toString(); //分割数据 ,通过空格来分割 hello,a String[] words = line.split(" "); //hello 1 //a 1 for (String word : words) { context.write(new Text(word),new IntWritable(1)); } } }
创建WordCountReducer.java
package org.conan.myhadoop.hdfs; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Reducer; import java.io.IOException; /** * Created by Administrator on 2017/8/16. */ public class WordCountReducer extends Reducer<Text,IntWritable,Text,IntWritable> { @Override protected void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException { Integer count = 0; for (IntWritable value : values) { count += value.get(); } context.write(key,new IntWritable(count)); } }
hdfs上传词频文件
mkdir /home/hadoop/ touch words vim words #内容如下 hello a hello b hello c #注意最后一个words前面需要带/ 即/words hdfs dfs -put /home/hadoop/words /words
put: Call From test/127.0.1.1 to 172.16.19.199:9000 failed on connection exception: java.net.ConnectException: 拒绝连接; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
hadoop namenode -format
执行以上命令解决这个问题。
然后再执行 hdfs dfs -put /home/hadoop/words /input 这个命令 把词频文件上传上去。
由于我的环境是远程windows10系统中的虚拟机ubuntu环境 所以windows10上面的nginx用作tcp端口转发配置如下：
stream { server { listen 6379; proxy_pass 172.16.19.199:6379; } server { listen 22; proxy_pass 172.16.19.199:22; } server { listen 9000; proxy_pass 172.16.19.199:9000; } server { listen 9000; proxy_pass 172.16.19.199:9000; } }
因为需要转发端口所以快速停止nginx.exe用windows命令taskkill /F /IM nginx.exe
你MapReduce执行多几次就会报如下错误：
Exception in thread "main" org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://172.16.17.190:9000/out07 already exists
这个时候需要用hdfs命令干掉这个目录。
hdfs dfs -rm -r hdfs://172.16.17.190:9000/out07
执行完毕继续执行main方法。
然后又报错：
2017-12-08 18:08:49,955 WARN [org.apache.hadoop.hdfs.DFSClient] - Failed to connect to /172.16.19.199:50010 for block, add to deadNodes and continue. java.net.ConnectException: Connection timed out: no further information java.net.ConnectException: Connection timed out: no further information at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206) at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:530)
Diagnostics: File file:/tmp/hadoop-yarn/staging/root/.staging/job_1512726205529_0003/job.splitmetainfo does not exist
java.io.FileNotFoundException: File file:/tmp/hadoop-yarn/staging/root/.staging/job_1512726205529_0003/job.splitmetainfo does not exist
