fix wal test

src/main/java/io/confluent/connect/hdfs/wal/FSWAL.java

@@ -42,6 +42,7 @@ public class FSWAL implements WAL {
   private String logFile = null;
   private Configuration conf = null;
   private Storage storage = null;
+  private long sleepIntervalMs = 1000L;
 
   public FSWAL(String logsDir, TopicPartition topicPart, Storage storage)
       throws ConnectException {
@@ -65,8 +66,11 @@ public void append(String tempFile, String committedFile) throws ConnectExceptio
     }
   }
 
+  public long getSleepIntervalMs() {
+    return sleepIntervalMs;
+  }
+
   public void acquireLease() throws ConnectException {
-    long sleepIntervalMs = 1000L;
     long MAX_SLEEP_INTERVAL_MS = 16000L;
     while (sleepIntervalMs < MAX_SLEEP_INTERVAL_MS) {
       try {

src/main/java/io/confluent/connect/hdfs/wal/WAL.java

@@ -27,4 +27,5 @@ public interface WAL {
   void truncate() throws ConnectException;
   void close() throws ConnectException;
   String getLogFile();
+  long getSleepIntervalMs();
 }

src/test/java/io/confluent/connect/hdfs/wal/WALTest.java

@@ -34,7 +34,7 @@ public class WALTest extends TestWithMiniDFSCluster {
   private static final String extension = ".avro";
 
   @Test
-  public void testWALMultiClient() throws Exception {
+  public void testMultiWALFromOneDFSClient() throws Exception {
     fs.delete(new Path(FileUtils.directoryName(url, topicsDir, TOPIC_PARTITION)), true);
 
     @SuppressWarnings("unchecked")
@@ -62,8 +62,8 @@ public void testWALMultiClient() throws Exception {
       @Override
       public void run() {
         try {
-          // holding the lease for awhile
-          Thread.sleep(3000);
+          // holding the lease for time that is less than wal2's retry interval, which is 1000 ms.
+          Thread.sleep(wal2.getSleepIntervalMs()-100);
           closed = true;
           wal1.close();
         } catch (ConnectException | InterruptedException e) {
@@ -73,7 +73,8 @@ public void run() {
     });
     thread.start();
 
-    Thread.sleep(3001);
+    // AcquireLease will try to acquire the same lease that wal1 is holding and fail
+    // It will then retry after waiting for 1000 ms.
     wal2.acquireLease();
     assertTrue(closed);
     wal2.apply();