HBASE-27365 Minimise block addition failures due to no space in bucket cache writers queue by introducing wait time (#4805)

Co-authored-by: Rajeshbabu Chintaguntla <[email protected]>

Author: chrajeshbabu

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/BlockCache.java

@@ -34,6 +34,19 @@ public interface BlockCache extends Iterable<CachedBlock> {
    */
   void cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean inMemory);
 
+  /**
+   * Add block to cache.
+   * @param cacheKey      The block's cache key.
+   * @param buf           The block contents wrapped in a ByteBuffer.
+   * @param inMemory      Whether block should be treated as in-memory
+   * @param waitWhenCache Whether to wait for the cache to be flushed mainly when BucketCache is
+   *                      configured.
+   */
+  default void cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean inMemory,
+    boolean waitWhenCache) {
+    cacheBlock(cacheKey, buf, inMemory);
+  }
+
   /**
    * Add block to cache (defaults to not in-memory).
    * @param cacheKey The block's cache key.

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/CombinedBlockCache.java

@@ -53,11 +53,17 @@ public long heapSize() {
 
   @Override
   public void cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean inMemory) {
+    cacheBlock(cacheKey, buf, inMemory, false);
+  }
+
+  @Override
+  public void cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean inMemory,
+    boolean waitWhenCache) {
     boolean metaBlock = isMetaBlock(buf.getBlockType());
     if (metaBlock) {
       l1Cache.cacheBlock(cacheKey, buf, inMemory);
     } else {
-      l2Cache.cacheBlock(cacheKey, buf, inMemory);
+      l2Cache.cacheBlock(cacheKey, buf, inMemory, waitWhenCache);
     }
   }
 

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderImpl.java

@@ -1328,7 +1328,7 @@ public HFileBlock readBlock(long dataBlockOffset, long onDiskBlockSize, final bo
           // Cache the block if necessary
           cacheConf.getBlockCache().ifPresent(cache -> {
             if (cacheBlock && cacheConf.shouldCacheBlockOnRead(category)) {
-              cache.cacheBlock(cacheKey, hfileBlock, cacheConf.isInMemory());
+              cache.cacheBlock(cacheKey, hfileBlock, cacheConf.isInMemory(), cacheOnly);
             }
           });
 
@@ -1341,8 +1341,8 @@ public HFileBlock readBlock(long dataBlockOffset, long onDiskBlockSize, final bo
         // Cache the block if necessary
         cacheConf.getBlockCache().ifPresent(cache -> {
           if (cacheBlock && cacheConf.shouldCacheBlockOnRead(category)) {
-            cache.cacheBlock(cacheKey, cacheCompressed ? hfileBlock : unpacked,
-              cacheConf.isInMemory());
+            // Using the wait on cache during compaction and prefetching.
+            cache.cacheBlock(cacheKey, cacheCompressed ? hfileBlock : unpacked, cacheOnly);
           }
         });
         if (unpacked != hfileBlock) {

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileWriterImpl.java

@@ -550,7 +550,7 @@ private void doCacheOnWrite(long offset) {
       HFileBlock cacheFormatBlock = blockWriter.getBlockForCaching(cacheConf);
       try {
         cache.cacheBlock(new BlockCacheKey(name, offset, true, cacheFormatBlock.getBlockType()),
-          cacheFormatBlock);
+          cacheFormatBlock, cacheConf.isInMemory(), true);
       } finally {
         // refCnt will auto increase when block add to Cache, see RAMCache#putIfAbsent
         cacheFormatBlock.release();

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java

@@ -175,13 +175,6 @@ public class BucketCache implements BlockCache, HeapSize {
 
   private static final int DEFAULT_CACHE_WAIT_TIME = 50;
 
-  /**
-   * Used in tests. If this flag is false and the cache speed is very fast, bucket cache will skip
-   * some blocks when caching. If the flag is true, we will wait until blocks are flushed to
-   * IOEngine.
-   */
-  boolean wait_when_cache = false;
-
   private final BucketCacheStats cacheStats = new BucketCacheStats();
 
   private final String persistencePath;
@@ -248,6 +241,10 @@ public class BucketCache implements BlockCache, HeapSize {
     "hbase.bucketcache.persistent.file.integrity.check.algorithm";
   private static final String DEFAULT_FILE_VERIFY_ALGORITHM = "MD5";
 
+  private static final String QUEUE_ADDITION_WAIT_TIME =
+    "hbase.bucketcache.queue.addition.waittime";
+  private static final long DEFAULT_QUEUE_ADDITION_WAIT_TIME = 0;
+  private long queueAdditionWaitTime;
   /**
    * Use {@link java.security.MessageDigest} class's encryption algorithms to check persistent file
    * integrity, default algorithm is MD5
@@ -288,6 +285,8 @@ public BucketCache(String ioEngineName, long capacity, int blockSize, int[] buck
     this.singleFactor = conf.getFloat(SINGLE_FACTOR_CONFIG_NAME, DEFAULT_SINGLE_FACTOR);
     this.multiFactor = conf.getFloat(MULTI_FACTOR_CONFIG_NAME, DEFAULT_MULTI_FACTOR);
     this.memoryFactor = conf.getFloat(MEMORY_FACTOR_CONFIG_NAME, DEFAULT_MEMORY_FACTOR);
+    this.queueAdditionWaitTime =
+      conf.getLong(QUEUE_ADDITION_WAIT_TIME, DEFAULT_QUEUE_ADDITION_WAIT_TIME);
     this.prefetchedFileListPath = conf.get(PREFETCH_PERSISTENCE_PATH_KEY);
 
     sanityCheckConfigs();
@@ -432,7 +431,19 @@ public void cacheBlock(BlockCacheKey cacheKey, Cacheable buf) {
    */
   @Override
   public void cacheBlock(BlockCacheKey cacheKey, Cacheable cachedItem, boolean inMemory) {
-    cacheBlockWithWait(cacheKey, cachedItem, inMemory, wait_when_cache);
+    cacheBlockWithWait(cacheKey, cachedItem, inMemory, false);
+  }
+
+  /**
+   * Cache the block with the specified name and buffer.
+   * @param cacheKey   block's cache key
+   * @param cachedItem block buffer
+   * @param inMemory   if block is in-memory
+   */
+  @Override
+  public void cacheBlock(BlockCacheKey cacheKey, Cacheable cachedItem, boolean inMemory,
+    boolean waitWhenCache) {
+    cacheBlockWithWait(cacheKey, cachedItem, inMemory, waitWhenCache && queueAdditionWaitTime > 0);
   }
 
   /**
@@ -491,7 +502,7 @@ protected void cacheBlockWithWaitInternal(BlockCacheKey cacheKey, Cacheable cach
     boolean successfulAddition = false;
     if (wait) {
       try {
-        successfulAddition = bq.offer(re, DEFAULT_CACHE_WAIT_TIME, TimeUnit.MILLISECONDS);
+        successfulAddition = bq.offer(re, queueAdditionWaitTime, TimeUnit.MILLISECONDS);
       } catch (InterruptedException e) {
         Thread.currentThread().interrupt();
       }

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

@@ -58,6 +58,7 @@
 import org.apache.hadoop.hbase.testclassification.IOTests;
 import org.apache.hadoop.hbase.testclassification.LargeTests;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.hadoop.hbase.util.Threads;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -119,7 +120,6 @@ public MockedBucketCache(String ioEngineName, long capacity, int blockSize, int[
       int writerThreads, int writerQLen, String persistencePath) throws IOException {
       super(ioEngineName, capacity, blockSize, bucketSizes, writerThreads, writerQLen,
         persistencePath);
-      super.wait_when_cache = true;
     }
 
     @Override
@@ -241,16 +241,16 @@ public static void waitUntilAllFlushedToBucket(BucketCache cache) throws Interru
   // BucketCache.cacheBlock is async, it first adds block to ramCache and writeQueue, then writer
   // threads will flush it to the bucket and put reference entry in backingMap.
   private void cacheAndWaitUntilFlushedToBucket(BucketCache cache, BlockCacheKey cacheKey,
-    Cacheable block) throws InterruptedException {
-    cache.cacheBlock(cacheKey, block);
+    Cacheable block, boolean waitWhenCache) throws InterruptedException {
+    cache.cacheBlock(cacheKey, block, false, waitWhenCache);
     waitUntilFlushedToBucket(cache, cacheKey);
   }
 
   @Test
   public void testMemoryLeak() throws Exception {
     final BlockCacheKey cacheKey = new BlockCacheKey("dummy", 1L);
     cacheAndWaitUntilFlushedToBucket(cache, cacheKey,
-      new CacheTestUtils.ByteArrayCacheable(new byte[10]));
+      new CacheTestUtils.ByteArrayCacheable(new byte[10]), true);
     long lockId = cache.backingMap.get(cacheKey).offset();
     ReentrantReadWriteLock lock = cache.offsetLock.getLock(lockId);
     lock.writeLock().lock();
@@ -265,7 +265,7 @@ public void run() {
     cache.blockEvicted(cacheKey, cache.backingMap.remove(cacheKey), true, true);
     assertEquals(0, cache.getBlockCount());
     cacheAndWaitUntilFlushedToBucket(cache, cacheKey,
-      new CacheTestUtils.ByteArrayCacheable(new byte[10]));
+      new CacheTestUtils.ByteArrayCacheable(new byte[10]), true);
     assertEquals(1, cache.getBlockCount());
     lock.writeLock().unlock();
     evictThread.join();
@@ -341,7 +341,8 @@ private void testRetrievalUtils(Path testDir, String ioEngineName)
         bucketCache.cacheBlock(block.getBlockName(), block.getBlock());
       }
       for (HFileBlockPair block : blocks) {
-        cacheAndWaitUntilFlushedToBucket(bucketCache, block.getBlockName(), block.getBlock());
+        cacheAndWaitUntilFlushedToBucket(bucketCache, block.getBlockName(), block.getBlock(),
+          false);
       }
       usedSize = bucketCache.getAllocator().getUsedSize();
       assertNotEquals(0, usedSize);
@@ -403,7 +404,8 @@ public void testRetrieveFromFileWithoutPersistence() throws Exception {
         bucketCache.cacheBlock(block.getBlockName(), block.getBlock());
       }
       for (HFileBlockPair block : blocks) {
-        cacheAndWaitUntilFlushedToBucket(bucketCache, block.getBlockName(), block.getBlock());
+        cacheAndWaitUntilFlushedToBucket(bucketCache, block.getBlockName(), block.getBlock(),
+          false);
       }
       usedSize = bucketCache.getAllocator().getUsedSize();
       assertNotEquals(0, usedSize);
@@ -786,7 +788,7 @@ public void testFreeBucketEntryRestoredFromFile() throws Exception {
 
       for (HFileBlockPair hfileBlockPair : hfileBlockPairs) {
         cacheAndWaitUntilFlushedToBucket(bucketCache, hfileBlockPair.getBlockName(),
-          hfileBlockPair.getBlock());
+          hfileBlockPair.getBlock(), false);
       }
       usedByteSize = bucketCache.getAllocator().getUsedSize();
       assertNotEquals(0, usedByteSize);
@@ -811,4 +813,63 @@ public void testFreeBucketEntryRestoredFromFile() throws Exception {
     }
   }
 
+  /**
+   * This test is for HBASE-26295, {@link BucketEntry} which is restored from a persistence file
+   * could not be freed even if corresponding {@link HFileBlock} is evicted from
+   * {@link BucketCache}.
+   */
+  @Test
+  public void testBlockAdditionWaitWhenCache() throws Exception {
+    try {
+      final Path dataTestDir = createAndGetTestDir();
+
+      String ioEngineName = "file:" + dataTestDir + "/bucketNoRecycler.cache";
+      String persistencePath = dataTestDir + "/bucketNoRecycler.persistence";
+
+      BucketCache bucketCache = new BucketCache(ioEngineName, capacitySize, constructedBlockSize,
+        constructedBlockSizes, 1, 1, persistencePath);
+      long usedByteSize = bucketCache.getAllocator().getUsedSize();
+      assertEquals(0, usedByteSize);
+
+      HFileBlockPair[] hfileBlockPairs =
+        CacheTestUtils.generateHFileBlocks(constructedBlockSize, 10);
+      // Add blocks
+      for (HFileBlockPair hfileBlockPair : hfileBlockPairs) {
+        bucketCache.cacheBlock(hfileBlockPair.getBlockName(), hfileBlockPair.getBlock(), false,
+          true);
+      }
+
+      // Max wait for 10 seconds.
+      long timeout = 10000;
+      // Wait for blocks size to match the number of blocks.
+      while (bucketCache.backingMap.size() != 10) {
+        if (timeout <= 0) break;
+        Threads.sleep(100);
+        timeout = -100;
+      }
+      for (HFileBlockPair hfileBlockPair : hfileBlockPairs) {
+        assertTrue(bucketCache.backingMap.containsKey(hfileBlockPair.getBlockName()));
+      }
+      usedByteSize = bucketCache.getAllocator().getUsedSize();
+      assertNotEquals(0, usedByteSize);
+      // persist cache to file
+      bucketCache.shutdown();
+      assertTrue(new File(persistencePath).exists());
+
+      // restore cache from file
+      bucketCache = new BucketCache(ioEngineName, capacitySize, constructedBlockSize,
+        constructedBlockSizes, writeThreads, writerQLen, persistencePath);
+      assertFalse(new File(persistencePath).exists());
+      assertEquals(usedByteSize, bucketCache.getAllocator().getUsedSize());
+
+      for (HFileBlockPair hfileBlockPair : hfileBlockPairs) {
+        BlockCacheKey blockCacheKey = hfileBlockPair.getBlockName();
+        bucketCache.evictBlock(blockCacheKey);
+      }
+      assertEquals(0, bucketCache.getAllocator().getUsedSize());
+      assertEquals(0, bucketCache.backingMap.size());
+    } finally {
+      HBASE_TESTING_UTILITY.cleanupTestDir();
+    }
+  }
 }

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

@@ -110,8 +110,6 @@ private void disableWriter() {
   // Flakey TestBucketCacheRefCnt.testBlockInRAMCache:121 expected:<3> but was:<2>
   public void testBlockInRAMCache() throws IOException {
     cache = create(1, 1000);
-    // Set this to true;
-    cache.wait_when_cache = true;
     disableWriter();
     final String prefix = "testBlockInRamCache";
     try {

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

@@ -117,7 +117,6 @@ public void testPrefetchPersistence() throws Exception {
     bucketCache = new BucketCache("file:" + testDir + "/bucket.cache", capacitySize,
       constructedBlockSize, constructedBlockSizes, writeThreads, writerQLen,
       testDir + "/bucket.persistence", 60 * 1000, conf);
-    bucketCache.wait_when_cache = true;
     cacheConf = new CacheConfig(conf, bucketCache);
 
     long usedSize = bucketCache.getAllocator().getUsedSize();
@@ -137,7 +136,6 @@ public void testPrefetchPersistence() throws Exception {
     bucketCache = new BucketCache("file:" + testDir + "/bucket.cache", capacitySize,
       constructedBlockSize, constructedBlockSizes, writeThreads, writerQLen,
       testDir + "/bucket.persistence", 60 * 1000, conf);
-    bucketCache.wait_when_cache = true;
     assertFalse(new File(testDir + "/bucket.persistence").exists());
     assertFalse(new File(testDir + "/prefetch.persistence").exists());
     assertTrue(usedSize != 0);

hbase-server/src/test/resources/hbase-site.xml

@@ -277,4 +277,9 @@
     <value>3</value>
     <description>Default is unbounded</description>
   </property>
+  <property>
+    <name>hbase.bucketcache.queue.addition.waittime</name>
+    <value>100</value>
+    <description>Default is 0</description>
+  </property>
 </configuration>