HBASE-26830 Rewrite TestLruBlockCache to make it more stable (#4212)

Signed-off-by: Xiaolin Ha <haxiaolin@apache.org>
(cherry picked from commit c3d0cc7040)

hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestLruBlockCache.java

@@ -66,6 +66,8 @@ public class TestLruBlockCache {
 
   private static final Logger LOG = LoggerFactory.getLogger(TestLruBlockCache.class);
 
+  private static final Configuration CONF = HBaseConfiguration.create();
+
   @Test
   public void testCacheEvictionThreadSafe() throws Exception {
     long maxSize = 100000;
@@ -74,13 +76,10 @@ public class TestLruBlockCache {
     final long blockSize = calculateBlockSizeDefault(maxSize, numBlocks);
     assertTrue("calculateBlockSize appears broken.", blockSize * numBlocks <= maxSize);
 
-    final Configuration conf = HBaseConfiguration.create();
     final LruBlockCache cache = new LruBlockCache(maxSize, blockSize);
     EvictionThread evictionThread = cache.getEvictionThread();
     assertTrue(evictionThread != null);
-    while (!evictionThread.isEnteringRun()) {
-      Thread.sleep(1);
-    }
+    Waiter.waitFor(CONF, 10000, 100, () -> evictionThread.isEnteringRun());
     final String hfileName = "hfile";
     int threads = 10;
     final int blocksPerThread = 5 * numBlocks;
@@ -103,7 +102,7 @@ public class TestLruBlockCache {
       service.shutdown();
       // The test may fail here if the evict thread frees the blocks too fast
       service.awaitTermination(10, TimeUnit.MINUTES);
-      Waiter.waitFor(conf, 10000, 100, new ExplainingPredicate<Exception>() {
+      Waiter.waitFor(CONF, 10000, 100, new ExplainingPredicate<Exception>() {
         @Override
         public boolean evaluate() throws Exception {
           return cache.getBlockCount() == 0;
@@ -132,9 +131,7 @@ public class TestLruBlockCache {
     CachedItem[] blocks = generateFixedBlocks(numBlocks + 1, blockSize, "block");
 
     // Make sure eviction thread has entered run method
-    while (!evictionThread.isEnteringRun()) {
-      Thread.sleep(10);
-    }
+    Waiter.waitFor(CONF, 10000, 10, () -> evictionThread.isEnteringRun());
 
     // Add all the blocks
     for (CachedItem block : blocks) {
@@ -142,12 +139,19 @@ public class TestLruBlockCache {
     }
 
     // wait until at least one eviction has run
-    int n = 0;
-    while(cache.getStats().getEvictionCount() == 0) {
-      Thread.sleep(200);
-      assertTrue("Eviction never happened.", n++ < 20);
+    Waiter.waitFor(CONF, 30000, 200, new ExplainingPredicate<Exception>() {
+
+      @Override
+      public boolean evaluate() throws Exception {
+        return cache.getStats().getEvictionCount() > 0;
       }
 
+      @Override
+      public String explainFailure() throws Exception {
+        return "Eviction never happened.";
+      }
+    });
+
     // let cache stabilize
     // On some systems, the cache will run multiple evictions before it attains
     // steady-state. For instance, after populating the cache with 10 blocks,
@@ -155,22 +159,20 @@ public class TestLruBlockCache {
     // evicts another. I think this is due to the delta between minSize and
     // acceptableSize, combined with variance between object overhead on
     // different environments.
-    n = 0;
-    for (long prevCnt = 0 /* < number of blocks added */,
-              curCnt = cache.getBlockCount();
-        prevCnt != curCnt; prevCnt = curCnt, curCnt = cache.getBlockCount()) {
+    int n = 0;
+    for (long prevCnt = 0 /* < number of blocks added */, curCnt =
+      cache.getBlockCount(); prevCnt != curCnt; prevCnt = curCnt, curCnt = cache.getBlockCount()) {
       Thread.sleep(200);
-      assertTrue("Cache never stabilized.", n++ < 20);
+      assertTrue("Cache never stabilized.", n++ < 100);
     }
 
     long evictionCount = cache.getStats().getEvictionCount();
     assertTrue(evictionCount >= 1);
-    System.out.println("Background Evictions run: " + evictionCount);
+    LOG.info("Background Evictions run: {}", evictionCount);
   }
 
   @Test
   public void testCacheSimple() throws Exception {
-
     long maxSize = 1000000;
     long blockSize = calculateBlockSizeDefault(maxSize, 101);
 
@@ -229,7 +231,6 @@ public class TestLruBlockCache {
 
   @Test
   public void testCacheEvictionSimple() throws Exception {
-
     long maxSize = 100000;
     long blockSize = calculateBlockSizeDefault(maxSize, 10);
 
@@ -269,7 +270,6 @@ public class TestLruBlockCache {
 
   @Test
   public void testCacheEvictionTwoPriorities() throws Exception {
-
     long maxSize = 100000;
     long blockSize = calculateBlockSizeDefault(maxSize, 10);
 
@@ -328,7 +328,6 @@ public class TestLruBlockCache {
 
   @Test
   public void testCacheEvictionThreePriorities() throws Exception {
-
     long maxSize = 100000;
     long blockSize = calculateBlockSize(maxSize, 10);
 
@@ -661,7 +660,6 @@ public class TestLruBlockCache {
   // test setMaxSize
   @Test
   public void testResizeBlockCache() throws Exception {
-
     long maxSize = 300000;
     long blockSize = calculateBlockSize(maxSize, 31);
 
@@ -684,7 +682,6 @@ public class TestLruBlockCache {
 
     // Add all blocks from all priorities
     for (int i = 0; i < 10; i++) {
-
       // Just add single blocks
       cache.cacheBlock(singleBlocks[i].cacheKey, singleBlocks[i]);