fix flaky test

helix-core/src/test/java/org/apache/helix/manager/zk/TestZkBucketDataAccessor.java

@@ -28,6 +28,7 @@
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.helix.AccessOption;
 import org.apache.helix.BaseDataAccessor;
 import org.apache.helix.BucketDataAccessor;
@@ -157,12 +158,13 @@ public void testMultipleWrites() throws Exception {
    */
   @Test(dependsOnMethods = "testMultipleWrites")
   public void testCompressedBucketRead() throws IOException {
-    _bucketDataAccessor.compressedBucketWrite(PATH, new HelixProperty(record));
-    HelixProperty readRecord = _bucketDataAccessor.compressedBucketRead(PATH, HelixProperty.class);
+    String path = PATH + "_" + TestHelper.getTestMethodName();
+    _bucketDataAccessor.compressedBucketWrite(path, new HelixProperty(record));
+    HelixProperty readRecord = _bucketDataAccessor.compressedBucketRead(path, HelixProperty.class);
     Assert.assertEquals(readRecord.getRecord().getSimpleField(NAME_KEY), NAME_KEY);
     Assert.assertEquals(readRecord.getRecord().getListField(NAME_KEY), LIST_FIELD);
     Assert.assertEquals(readRecord.getRecord().getMapField(NAME_KEY), MAP_FIELD);
-    _bucketDataAccessor.compressedBucketDelete(PATH);
+    _bucketDataAccessor.compressedBucketDelete(path);
   }
 
   /**
@@ -194,29 +196,35 @@ public void testLargeWriteAndRead() throws IOException {
    * Test to ensure bucket GC still occurs in high frequency write scenarios.
    */
   @Test(dependsOnMethods = "testLargeWriteAndRead")
-  public void testGCScheduler() throws IOException, InterruptedException {
+  public void testGCCompletesUnderHighFrequency() throws Exception {
+    String path = PATH + "_" + TestHelper.getTestMethodName();
     long gcTTL = 1000; // GC schedule for 1 second after write
     ZkBucketDataAccessor fastGCBucketDataAccessor = new ZkBucketDataAccessor(_zkClient, 50 * 1024, gcTTL);
 
-    int writeCount = 10;
-    for (int i = 0; i < writeCount; i++) {
-      Thread.sleep(gcTTL / 2);
-      Assert.assertTrue(fastGCBucketDataAccessor.compressedBucketWrite(PATH, new HelixProperty(record)));
-    }
-    List<String> children = _zkBaseDataAccessor.getChildNames(PATH, AccessOption.PERSISTENT);
-    // remove from list if name cant be parsed into long (aka not a version count node)
-    children.removeIf(name -> {
-      try {
-        Long.parseLong(name);
-        return false;
-      } catch (NumberFormatException e) {
-        return true;
+    AtomicInteger writeCount = new AtomicInteger(0);
+    // Below verifier continuously writes to the same path and then checks if the # of children is less than the # of
+    // times we have written. This will only be true once the GC has cleaned up old versions, which will occur once the
+    // GC time for the first write has passed.
+    Assert.assertTrue(TestHelper.verify(() -> {
+      Assert.assertTrue(fastGCBucketDataAccessor.compressedBucketWrite(path, new HelixProperty(record)));
+      Thread.sleep(gcTTL/4);
+      List<String> children = _zkBaseDataAccessor.getChildNames(path, AccessOption.PERSISTENT);
+      // remove from list if name cant be parsed into long (aka not a version count node)
+      children.removeIf(name -> {
+        try {
+          Long.parseLong(name);
+          return false;
+        } catch (NumberFormatException e) {
+          return true;
+        }
+      });
+      boolean result = children.size() < writeCount.incrementAndGet();
+      if (!result) {
+        System.out.println("Expecting stale versions to have been cleaned up. Write count was: " + writeCount +
+            ", children were: " + children);
       }
-    });
-
-    Assert.assertTrue(children.size() < writeCount,
-        "Expecting stale versions to cleaned up. Children were: " + children);
-    System.out.print("Children after GC: " + children);
+      return result;
+    }, TestHelper.WAIT_DURATION));
   }
 
   private HelixProperty createLargeHelixProperty(String name, int numEntries) {