HADOOP-12634. Change Lazy Rename Pending Operation Completion of WASB to address case of potential data loss due to partial copy. Contributed by Gaurav Kanade.

This commit is contained in:
cnauroth 2016-01-06 11:15:59 -08:00
parent 67c9780609
commit 978bbdfeb2
3 changed files with 27 additions and 33 deletions

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@ -1553,6 +1553,10 @@ Release 2.8.0 - UNRELEASED
HADOOP-12689. S3 filesystem operations stopped working correctly
(Matt Paduano via raviprak)
HADOOP-12634. Change Lazy Rename Pending Operation Completion of WASB to
address case of potential data loss due to partial copy
(Gaurav Kanade via cnauroth)
Release 2.7.3 - UNRELEASED
INCOMPATIBLE CHANGES

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@ -536,45 +536,13 @@ public class NativeAzureFileSystem extends FileSystem {
Path dstFile = fullPath(dstKey, fileName);
boolean srcExists = fs.exists(srcFile);
boolean dstExists = fs.exists(dstFile);
if (srcExists && !dstExists) {
if(srcExists) {
// Rename gets exclusive access (via a lease) for HBase write-ahead log
// (WAL) file processing correctness. See the rename code for details.
String srcName = fs.pathToKey(srcFile);
String dstName = fs.pathToKey(dstFile);
fs.getStoreInterface().rename(srcName, dstName, true, null);
} else if (srcExists && dstExists) {
// Get a lease on source to block write access.
String srcName = fs.pathToKey(srcFile);
SelfRenewingLease lease = null;
try {
lease = fs.acquireLease(srcFile);
// Delete the file. This will free the lease too.
fs.getStoreInterface().delete(srcName, lease);
} catch(AzureException e) {
String errorCode = "";
try {
StorageException e2 = (StorageException) e.getCause();
errorCode = e2.getErrorCode();
} catch(Exception e3) {
// do nothing if cast fails
}
// If the rename already finished do nothing
if(!errorCode.equals("BlobNotFound")){
throw e;
}
} finally {
try {
if(lease != null){
lease.free();
}
} catch(StorageException e) {
LOG.warn("Unable to free lease because: " + e.getMessage());
}
}
} else if (!srcExists && dstExists) {
// The rename already finished, so do nothing.
;
} else {

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@ -24,6 +24,8 @@ import static org.junit.Assert.assertTrue;
import java.util.concurrent.CountDownLatch;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
@ -43,6 +45,26 @@ public class TestNativeAzureFileSystemLive extends
return AzureBlobStorageTestAccount.create();
}
@Test
public void testLazyRenamePendingCanOverwriteExistingFile()
throws Exception {
final String SRC_FILE_KEY = "srcFile";
final String DST_FILE_KEY = "dstFile";
Path srcPath = new Path(SRC_FILE_KEY);
FSDataOutputStream srcStream = fs.create(srcPath);
assertTrue(fs.exists(srcPath));
Path dstPath = new Path(DST_FILE_KEY);
FSDataOutputStream dstStream = fs.create(dstPath);
assertTrue(fs.exists(dstPath));
NativeAzureFileSystem nfs = (NativeAzureFileSystem)fs;
final String fullSrcKey = nfs.pathToKey(nfs.makeAbsolute(srcPath));
final String fullDstKey = nfs.pathToKey(nfs.makeAbsolute(dstPath));
nfs.getStoreInterface().rename(fullSrcKey, fullDstKey, true, null);
assertTrue(fs.exists(dstPath));
assertFalse(fs.exists(srcPath));
IOUtils.cleanup(null, srcStream);
IOUtils.cleanup(null, dstStream);
}
/**
* Tests fs.delete() function to delete a blob when another blob is holding a
* lease on it. Delete if called without a lease should fail if another process