[FLINK-1115] Local file streams retry file creation on FileNotFoundException...

[FLINK-1115] Local file streams retry file creation on FileNotFoundException to increase resilience against spurious failures in tests

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalDataOutputStream.java

@@ -16,10 +16,10 @@
  * limitations under the License.
  */
 
-
 package org.apache.flink.core.fs.local;
 
 import java.io.File;
+import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 
@@ -28,14 +28,15 @@ import org.apache.flink.core.fs.FSDataOutputStream;
 /**
  * The <code>LocalDataOutputStream</code> class is a wrapper class for a data
  * output stream to the local file system.
- * 
  */
 public class LocalDataOutputStream extends FSDataOutputStream {
 
+	private static final int MAX_OPEN_TRIES = 3;
+	
 	/**
 	 * The file output stream used to write data.
 	 */
-	private FileOutputStream fos = null;
+	private FileOutputStream fos;
 
 	/**
 	 * Constructs a new <code>LocalDataOutputStream</code> object from a given {@link File} object.
@@ -46,26 +47,34 @@ public class LocalDataOutputStream extends FSDataOutputStream {
 	 *         thrown if the data output stream cannot be created
 	 */
 	public LocalDataOutputStream(final File file) throws IOException {
+		// we allow multiple tries to create the file, to increase resilience against spurious I/O failures
 		
+		FileNotFoundException lastException = null;
+		
+		for (int attempt = 0; attempt < MAX_OPEN_TRIES; attempt++) {
+			try {
 				this.fos = new FileOutputStream(file);
+				return;
+			}
+			catch (FileNotFoundException e) {
+				lastException = e;
+			}
+		}
+		throw lastException;
 	}
-
 
 	@Override
 	public void write(final int b) throws IOException {
 		fos.write(b);
 	}
 
-
 	@Override
 	public void write(final byte[] b, final int off, final int len) throws IOException {
 		fos.write(b, off, len);
 	}
 
-
 	@Override
 	public void close() throws IOException {
-
 		fos.close();
 	}
 }