diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsConstants.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsConstants.java index 07c16b2235..344048f0ce 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsConstants.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsConstants.java @@ -44,4 +44,6 @@ public interface FsConstants { public static final String VIEWFS_SCHEME = "viewfs"; String FS_VIEWFS_OVERLOAD_SCHEME_TARGET_FS_IMPL_PATTERN = "fs.viewfs.overload.scheme.target.%s.impl"; + String VIEWFS_TYPE = "viewfs"; + String VIEWFSOS_TYPE = "viewfsOverloadScheme"; } diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java index 3d709b13bf..422e7337b5 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java @@ -34,6 +34,7 @@ import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileAlreadyExistsException; +import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.UnsupportedFileSystemException; import org.apache.hadoop.security.UserGroupInformation; @@ -67,7 +68,7 @@ enum ResultKind { // the root of the mount table private final INode root; // the fallback filesystem - private final INodeLink rootFallbackLink; + private INodeLink rootFallbackLink; // the homedir for this mount table private final String homedirPrefix; private List> mountPoints = new ArrayList>(); @@ -460,7 +461,8 @@ Configuration getConfig() { * @throws FileAlreadyExistsException * @throws IOException */ - protected InodeTree(final Configuration config, final String viewName) + protected InodeTree(final Configuration config, final String viewName, + final URI theUri, boolean initingUriAsFallbackOnNoMounts) throws UnsupportedFileSystemException, URISyntaxException, FileAlreadyExistsException, IOException { String mountTableName = viewName; @@ -596,9 +598,19 @@ protected InodeTree(final Configuration config, final String viewName) } if (!gotMountTableEntry) { - throw new IOException( - "ViewFs: Cannot initialize: Empty Mount table in config for " + - "viewfs://" + mountTableName + "/"); + if (!initingUriAsFallbackOnNoMounts) { + throw new IOException( + "ViewFs: Cannot initialize: Empty Mount table in config for " + + "viewfs://" + mountTableName + "/"); + } + StringBuilder msg = + new StringBuilder("Empty mount table detected for ").append(theUri) + .append(" and considering itself as a linkFallback."); + FileSystem.LOG.info(msg.toString()); + rootFallbackLink = + new INodeLink(mountTableName, ugi, getTargetFileSystem(theUri), + theUri); + getRootDir().addFallbackLink(rootFallbackLink); } } diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java index 0beeda253a..1fc531e056 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java @@ -258,6 +258,14 @@ public String getScheme() { return FsConstants.VIEWFS_SCHEME; } + /** + * Returns the ViewFileSystem type. + * @return viewfs + */ + String getType() { + return FsConstants.VIEWFS_TYPE; + } + /** * Called after a new FileSystem instance is constructed. * @param theUri a uri whose authority section names the host, port, etc. for @@ -284,7 +292,10 @@ public void initialize(final URI theUri, final Configuration conf) } try { myUri = new URI(getScheme(), authority, "/", null, null); - fsState = new InodeTree(conf, tableName) { + boolean initingUriAsFallbackOnNoMounts = + !FsConstants.VIEWFS_TYPE.equals(getType()); + fsState = new InodeTree(conf, tableName, theUri, + initingUriAsFallbackOnNoMounts) { @Override protected FileSystem getTargetFileSystem(final URI uri) throws URISyntaxException, IOException { diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystemOverloadScheme.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystemOverloadScheme.java index 2f3359d32e..2165a3f9ee 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystemOverloadScheme.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystemOverloadScheme.java @@ -95,6 +95,10 @@ * be considered as the mount table name. When the passed uri has hostname:port, * it will simply ignore the port number and only hostname will be considered as * the mount table name. + * (3) If there are no mount links configured with the initializing uri's + * hostname as the mount table name, then it will automatically consider the + * current uri as fallback( ex: fs.viewfs.mounttable..linkFallBack) + * target fs uri. *****************************************************************************/ @InterfaceAudience.LimitedPrivate({ "MapReduce", "HBase", "Hive" }) @InterfaceStability.Evolving @@ -109,6 +113,14 @@ public String getScheme() { return myUri.getScheme(); } + /** + * Returns the ViewFileSystem type. + * @return viewfs + */ + String getType() { + return FsConstants.VIEWFSOS_TYPE; + } + @Override public void initialize(URI theUri, Configuration conf) throws IOException { this.myUri = theUri; diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java index a63960c55d..95b596bde3 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java @@ -196,7 +196,16 @@ URI[] getTargets() { return targets; } } - + + /** + * Returns the ViewFileSystem type. + * + * @return viewfs + */ + String getType() { + return FsConstants.VIEWFS_TYPE; + } + public ViewFs(final Configuration conf) throws IOException, URISyntaxException { this(FsConstants.VIEWFS_URI, conf); @@ -222,7 +231,10 @@ public ViewFs(final Configuration conf) throws IOException, CONFIG_VIEWFS_MOUNT_LINKS_AS_SYMLINKS_DEFAULT); // Now build client side view (i.e. client side mount table) from config. String authority = theUri.getAuthority(); - fsState = new InodeTree(conf, authority) { + boolean initingUriAsFallbackOnNoMounts = + !FsConstants.VIEWFS_TYPE.equals(getType()); + fsState = new InodeTree(conf, authority, theUri, + initingUriAsFallbackOnNoMounts) { @Override protected AbstractFileSystem getTargetFileSystem(final URI uri) diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsConfig.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsConfig.java index 136837fc80..56f5b2d997 100644 --- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsConfig.java +++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsConfig.java @@ -39,7 +39,7 @@ public void testInvalidConfig() throws IOException, URISyntaxException { class Foo { } - new InodeTree(conf, null) { + new InodeTree(conf, null, null, false) { @Override protected Foo getTargetFileSystem(final URI uri) { diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsOverloadSchemeListStatus.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsOverloadSchemeListStatus.java index 0cf691481f..300fdd8b33 100644 --- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsOverloadSchemeListStatus.java +++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsOverloadSchemeListStatus.java @@ -46,9 +46,17 @@ public class TestViewFsOverloadSchemeListStatus { private static final File TEST_DIR = GenericTestUtils.getTestDir(TestViewfsFileStatus.class.getSimpleName()); + private Configuration conf; + private static final String FILE_NAME = "file"; @Before public void setUp() { + conf = new Configuration(); + conf.set(String.format("fs.%s.impl", FILE_NAME), + ViewFileSystemOverloadScheme.class.getName()); + conf.set(String + .format(FsConstants.FS_VIEWFS_OVERLOAD_SCHEME_TARGET_FS_IMPL_PATTERN, + FILE_NAME), LocalFileSystem.class.getName()); FileUtil.fullyDelete(TEST_DIR); assertTrue(TEST_DIR.mkdirs()); } @@ -77,15 +85,9 @@ public void testListStatusACL() throws IOException, URISyntaxException { File childDir = new File(TEST_DIR, childDirectoryName); childDir.mkdirs(); - Configuration conf = new Configuration(); ConfigUtil.addLink(conf, "/file", infile.toURI()); ConfigUtil.addLink(conf, "/dir", childDir.toURI()); - String fileScheme = "file"; - conf.set(String.format("fs.%s.impl", fileScheme), - ViewFileSystemOverloadScheme.class.getName()); - conf.set(String - .format(FsConstants.FS_VIEWFS_OVERLOAD_SCHEME_TARGET_FS_IMPL_PATTERN, - fileScheme), LocalFileSystem.class.getName()); + String fileUriStr = "file:///"; try (FileSystem vfs = FileSystem.get(new URI(fileUriStr), conf)) { assertEquals(ViewFileSystemOverloadScheme.class, vfs.getClass()); @@ -95,9 +97,8 @@ public void testListStatusACL() throws IOException, URISyntaxException { .getRawFileSystem(new Path(fileUriStr), conf); FileStatus fileStat = localFs.getFileStatus(new Path(infile.getPath())); FileStatus dirStat = localFs.getFileStatus(new Path(childDir.getPath())); - for (FileStatus status : statuses) { - if (status.getPath().getName().equals(fileScheme)) { + if (status.getPath().getName().equals(FILE_NAME)) { assertEquals(fileStat.getPermission(), status.getPermission()); } else { assertEquals(dirStat.getPermission(), status.getPermission()); @@ -111,7 +112,7 @@ public void testListStatusACL() throws IOException, URISyntaxException { statuses = vfs.listStatus(new Path("/")); for (FileStatus status : statuses) { - if (status.getPath().getName().equals(fileScheme)) { + if (status.getPath().getName().equals(FILE_NAME)) { assertEquals(FsPermission.valueOf("-rwxr--r--"), status.getPermission()); assertFalse(status.isDirectory()); @@ -124,6 +125,24 @@ public void testListStatusACL() throws IOException, URISyntaxException { } } + /** + * Tests that ViewFSOverloadScheme should consider initialized fs as fallback + * if there are no mount links configured. + */ + @Test(timeout = 30000) + public void testViewFSOverloadSchemeWithoutAnyMountLinks() throws Exception { + try (FileSystem fs = FileSystem.get(TEST_DIR.toPath().toUri(), conf)) { + ViewFileSystemOverloadScheme vfs = (ViewFileSystemOverloadScheme) fs; + assertEquals(0, vfs.getMountPoints().length); + Path testFallBack = new Path("test", FILE_NAME); + assertTrue(vfs.mkdirs(testFallBack)); + FileStatus[] status = vfs.listStatus(testFallBack.getParent()); + assertEquals(FILE_NAME, status[0].getPath().getName()); + assertEquals(testFallBack.getName(), + vfs.getFileLinkStatus(testFallBack).getPath().getName()); + } + } + @AfterClass public static void cleanup() throws IOException { FileUtil.fullyDelete(TEST_DIR); diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ViewFsOverloadScheme.md b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ViewFsOverloadScheme.md index 38113cbbb0..564bc034e7 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ViewFsOverloadScheme.md +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ViewFsOverloadScheme.md @@ -33,8 +33,9 @@ Mount link configurations key, value formats are same as in [ViewFS Guide](./Vie If a user wants to continue use the same fs.defaultFS and wants to have more mount points, then mount link configurations should have the ViewFileSystemOverloadScheme initialized uri's hostname as the mount table name. Example if fs.defaultFS is `hdfs://mycluster`, then the mount link configuration key name should be like in the following format `fs.viewfs.mounttable.*mycluster*.link.`. Even if the initialized fs uri has hostname:port, it will simply ignore the port number and only consider the hostname as the mount table name. We will discuss more example configurations in following sections. +If there are no mount links configured with the initializing uri's hostname as the mount table name, then it will automatically consider the current uri as fallback(`fs.viewfs.mounttable.*mycluster*.linkFallback`) target fs uri. -Another important improvement with the ViewFileSystemOverloadScheme is, administrators need not copy the `mount-table.xml` configuration file to 1000s of client nodes. Instead they can keep the mount-table configuration file in a Hadoop compatible file system. So, keeping the configuration file in a central place makes administrators life easier as they can update mount-table in single place. +Another important improvement with the ViewFileSystemOverloadScheme is, administrators need not copy the `mount-table.xml` configuration file to 1000s of client nodes. Instead, they can keep the mount-table configuration file in a Hadoop compatible file system. So, keeping the configuration file in a central place makes administrators life easier as they can update mount-table in single place. ### Enabling View File System Overload Scheme diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestViewFileSystemOverloadSchemeWithDFSAdmin.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestViewFileSystemOverloadSchemeWithDFSAdmin.java index aea4704711..39df141a37 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestViewFileSystemOverloadSchemeWithDFSAdmin.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestViewFileSystemOverloadSchemeWithDFSAdmin.java @@ -228,16 +228,22 @@ public void testSafeModeShouldFailOnLocalTargetFS() throws Exception { } /** - * Tests safemode with ViewFSOverloadScheme, but without mounttables. + * Tests safemode get with ViewFSOverloadScheme, but without any mount links + * configured. The ViewFSOverloadScheme should consider initialized fs as + * fallback fs automatically. */ @Test - public void testSafeModeShouldFailWithoutMountTables() throws Exception { + public void testGetSafemodeWithoutMountLinksConfigured() throws Exception { final DFSAdmin dfsAdmin = new DFSAdmin(conf); - String uri = defaultFSURI.toString(); - redirectStream(); - int ret = ToolRunner.run(dfsAdmin, - new String[] {"-fs", uri, "-safemode", "enter" }); - assertEquals(-1, ret); + try { + redirectStream(); + int ret = ToolRunner.run(dfsAdmin, + new String[] {"-fs", defaultFSURI.toString(), "-safemode", "get"}); + assertOutMsg("Safe mode is OFF", 0); + assertEquals(0, ret); + } finally { + dfsAdmin.close(); + } } /**