diff --git a/hbase-common/src/main/resources/hbase-default.xml b/hbase-common/src/main/resources/hbase-default.xml
index ad6f6456782..c8ab48a7ff0 100644
--- a/hbase-common/src/main/resources/hbase-default.xml
+++ b/hbase-common/src/main/resources/hbase-default.xml
@@ -925,8 +925,10 @@ possible configurations would overwhelm and obscure the important.
hbase.bucketcache.ioengine
Where to store the contents of the bucketcache. One of: offheap,
- file, files or mmap. If a file or files, set it to file(s):PATH_TO_FILE.
- mmap means the content will be in an mmaped file. Use mmap:PATH_TO_FILE.
+ file, files, mmap or pmem. If a file or files, set it to file(s):PATH_TO_FILE.
+ mmap means the content will be in an mmaped file. Use mmap:PATH_TO_FILE. 'pmem'
+ is bucket cache over a file on the persistent memory device.
+ Use pmem:PATH_TO_FILE.
See http://hbase.apache.org/book.html#offheap.blockcache for more information.
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
index 5a21bada3d0..470c4f7eebe 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
@@ -379,7 +379,15 @@ public class BucketCache implements BlockCache, HeapSize {
} else if (ioEngineName.startsWith("offheap")) {
return new ByteBufferIOEngine(capacity);
} else if (ioEngineName.startsWith("mmap:")) {
- return new FileMmapEngine(ioEngineName.substring(5), capacity);
+ return new ExclusiveMemoryMmapIOEngine(ioEngineName.substring(5), capacity);
+ } else if (ioEngineName.startsWith("pmem:")) {
+ // This mode of bucket cache creates an IOEngine over a file on the persistent memory
+ // device. Since the persistent memory device has its own address space the contents
+ // mapped to this address space does not get swapped out like in the case of mmapping
+ // on to DRAM. Hence the cells created out of the hfile blocks in the pmem bucket cache
+ // can be directly referred to without having to copy them onheap. Once the RPC is done,
+ // the blocks can be returned back as in case of ByteBufferIOEngine.
+ return new SharedMemoryMmapIOEngine(ioEngineName.substring(5), capacity);
} else {
throw new IllegalArgumentException(
"Don't understand io engine name for cache- prefix with file:, files:, mmap: or offheap");
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/ExclusiveMemoryMmapIOEngine.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/ExclusiveMemoryMmapIOEngine.java
new file mode 100644
index 00000000000..8b024f00d22
--- /dev/null
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/ExclusiveMemoryMmapIOEngine.java
@@ -0,0 +1,50 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.hadoop.hbase.io.hfile.bucket;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.apache.hadoop.hbase.io.hfile.Cacheable;
+import org.apache.hadoop.hbase.io.hfile.Cacheable.MemoryType;
+import org.apache.hadoop.hbase.io.hfile.CacheableDeserializer;
+import org.apache.hadoop.hbase.nio.SingleByteBuff;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * IO engine that stores data to a file on the local block device using memory mapping
+ * mechanism
+ */
+@InterfaceAudience.Private
+public class ExclusiveMemoryMmapIOEngine extends FileMmapIOEngine {
+ static final Logger LOG = LoggerFactory.getLogger(ExclusiveMemoryMmapIOEngine.class);
+
+ public ExclusiveMemoryMmapIOEngine(String filePath, long capacity) throws IOException {
+ super(filePath, capacity);
+ }
+
+ @Override
+ public Cacheable read(long offset, int length, CacheableDeserializer deserializer)
+ throws IOException {
+ byte[] dst = new byte[length];
+ bufferArray.getMultiple(offset, length, dst);
+ return deserializer.deserialize(new SingleByteBuff(ByteBuffer.wrap(dst)), true,
+ MemoryType.EXCLUSIVE);
+ }
+}
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/FileMmapEngine.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/FileMmapIOEngine.java
similarity index 66%
rename from hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/FileMmapEngine.java
rename to hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/FileMmapIOEngine.java
index 82f42cda2ac..9580efe35f0 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/FileMmapEngine.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/FileMmapIOEngine.java
@@ -1,20 +1,19 @@
/**
- * Copyright The Apache Software Foundation
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with this
- * work for additional information regarding copyright ownership. The ASF
- * licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
+ * http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
*/
package org.apache.hadoop.hbase.io.hfile.bucket;
@@ -24,33 +23,31 @@ import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.concurrent.atomic.AtomicInteger;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
import org.apache.hadoop.hbase.io.hfile.Cacheable;
-import org.apache.hadoop.hbase.io.hfile.Cacheable.MemoryType;
import org.apache.hadoop.hbase.io.hfile.CacheableDeserializer;
import org.apache.hadoop.hbase.nio.ByteBuff;
-import org.apache.hadoop.hbase.nio.SingleByteBuff;
import org.apache.hadoop.hbase.util.ByteBufferAllocator;
import org.apache.hadoop.hbase.util.ByteBufferArray;
import org.apache.hadoop.util.StringUtils;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
/**
- * IO engine that stores data to a file on the local file system using memory mapping
+ * IO engine that stores data to a file on the specified file system using memory mapping
* mechanism
*/
@InterfaceAudience.Private
-public class FileMmapEngine implements IOEngine {
- static final Logger LOG = LoggerFactory.getLogger(FileMmapEngine.class);
+public abstract class FileMmapIOEngine implements IOEngine {
+ static final Logger LOG = LoggerFactory.getLogger(FileMmapIOEngine.class);
- private final String path;
- private long size;
- private ByteBufferArray bufferArray;
+ protected final String path;
+ protected long size;
+ protected ByteBufferArray bufferArray;
private final FileChannel fileChannel;
private RandomAccessFile raf = null;
- public FileMmapEngine(String filePath, long capacity) throws IOException {
+ public FileMmapIOEngine(String filePath, long capacity) throws IOException {
this.path = filePath;
this.size = capacity;
long fileSize = 0;
@@ -64,13 +61,15 @@ public class FileMmapEngine implements IOEngine {
LOG.error("Can't create bucket cache file " + filePath, fex);
throw fex;
} catch (IOException ioex) {
- LOG.error("Can't extend bucket cache file; insufficient space for "
- + StringUtils.byteDesc(fileSize), ioex);
+ LOG.error(
+ "Can't extend bucket cache file; insufficient space for " + StringUtils.byteDesc(fileSize),
+ ioex);
shutdown();
throw ioex;
}
ByteBufferAllocator allocator = new ByteBufferAllocator() {
AtomicInteger pos = new AtomicInteger(0);
+
@Override
public ByteBuffer allocate(long size) throws IOException {
ByteBuffer buffer = fileChannel.map(java.nio.channels.FileChannel.MapMode.READ_WRITE,
@@ -87,8 +86,8 @@ public class FileMmapEngine implements IOEngine {
@Override
public String toString() {
- return "ioengine=" + this.getClass().getSimpleName() + ", path=" + this.path +
- ", size=" + String.format("%,d", this.size);
+ return "ioengine=" + this.getClass().getSimpleName() + ", path=" + this.path + ", size="
+ + String.format("%,d", this.size);
}
/**
@@ -97,17 +96,13 @@ public class FileMmapEngine implements IOEngine {
*/
@Override
public boolean isPersistent() {
+ // TODO : HBASE-21981 needed for persistence to really work
return true;
}
@Override
- public Cacheable read(long offset, int length, CacheableDeserializer deserializer)
- throws IOException {
- byte[] dst = new byte[length];
- bufferArray.getMultiple(offset, length, dst);
- return deserializer.deserialize(new SingleByteBuff(ByteBuffer.wrap(dst)), true,
- MemoryType.EXCLUSIVE);
- }
+ public abstract Cacheable read(long offset, int length,
+ CacheableDeserializer deserializer) throws IOException;
/**
* Transfers data from the given byte buffer to file
@@ -119,7 +114,7 @@ public class FileMmapEngine implements IOEngine {
public void write(ByteBuffer srcBuffer, long offset) throws IOException {
assert srcBuffer.hasArray();
bufferArray.putMultiple(offset, srcBuffer.remaining(), srcBuffer.array(),
- srcBuffer.arrayOffset());
+ srcBuffer.arrayOffset());
}
@Override
@@ -127,9 +122,9 @@ public class FileMmapEngine implements IOEngine {
// This singleByteBuff can be considered to be array backed
assert srcBuffer.hasArray();
bufferArray.putMultiple(offset, srcBuffer.remaining(), srcBuffer.array(),
- srcBuffer.arrayOffset());
-
+ srcBuffer.arrayOffset());
}
+
/**
* Sync the data to file after writing
* @throws IOException
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/SharedMemoryMmapIOEngine.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/SharedMemoryMmapIOEngine.java
new file mode 100644
index 00000000000..b6a7a571f4f
--- /dev/null
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/SharedMemoryMmapIOEngine.java
@@ -0,0 +1,64 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.io.hfile.bucket;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hbase.io.hfile.Cacheable;
+import org.apache.hadoop.hbase.io.hfile.Cacheable.MemoryType;
+import org.apache.hadoop.hbase.io.hfile.CacheableDeserializer;
+import org.apache.hadoop.hbase.nio.ByteBuff;
+import org.apache.yetus.audience.InterfaceAudience;
+
+/**
+ * IO engine that stores data in pmem devices such as DCPMM. This engine also mmaps the file from
+ * the given path. But note that this path has to be a path on the pmem device so that when mmapped
+ * the file's address is mapped to the Pmem's address space and not in the DRAM. Since this address
+ * space is exclusive for the Pmem device there is no swapping out of the mmapped contents that
+ * generally happens when DRAM's free space is not enough to hold the specified file's mmapped
+ * contents. This gives us the option of using the {@code MemoryType#SHARED} type when serving the
+ * data from this pmem address space. We need not copy the blocks to the onheap space as we need to
+ * do for the case of {@code ExclusiveMemoryMmapIOEngine}.
+ */
+@InterfaceAudience.Private
+public class SharedMemoryMmapIOEngine extends FileMmapIOEngine {
+
+ // TODO this will support only one path over Pmem. To make use of multiple Pmem devices mounted,
+ // we need to support multiple paths like files IOEngine. Support later.
+ public SharedMemoryMmapIOEngine(String filePath, long capacity) throws IOException {
+ super(filePath, capacity);
+ }
+
+ @Override
+ public boolean usesSharedMemory() {
+ return true;
+ }
+
+ @Override
+ public Cacheable read(long offset, int length, CacheableDeserializer deserializer)
+ throws IOException {
+ ByteBuff dstBuffer = bufferArray.asSubByteBuff(offset, length);
+ // Here the buffer that is created directly refers to the buffer in the actual buckets.
+ // When any cell is referring to the blocks created out of these buckets then it means that
+ // those cells are referring to a shared memory area which if evicted by the BucketCache would
+ // lead to corruption of results. Hence we set the type of the buffer as SHARED_MEMORY
+ // so that the readers using this block are aware of this fact and do the necessary action
+ // to prevent eviction till the results are either consumed or copied
+ return deserializer.deserialize(dstBuffer, true, MemoryType.SHARED);
+ }
+}
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestFileMmapEngine.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestExclusiveMemoryMmapEngine.java
similarity index 90%
rename from hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestFileMmapEngine.java
rename to hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestExclusiveMemoryMmapEngine.java
index 2748d80bdba..d0d8c8a7dda 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestFileMmapEngine.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestExclusiveMemoryMmapEngine.java
@@ -32,21 +32,21 @@ import org.junit.Test;
import org.junit.experimental.categories.Category;
/**
- * Basic test for {@link FileMmapEngine}
+ * Basic test for {@link ExclusiveMemoryMmapIOEngine}
*/
@Category({IOTests.class, SmallTests.class})
-public class TestFileMmapEngine {
+public class TestExclusiveMemoryMmapEngine {
@ClassRule
public static final HBaseClassTestRule CLASS_RULE =
- HBaseClassTestRule.forClass(TestFileMmapEngine.class);
+ HBaseClassTestRule.forClass(TestExclusiveMemoryMmapEngine.class);
@Test
public void testFileMmapEngine() throws IOException {
int size = 2 * 1024 * 1024; // 2 MB
String filePath = "testFileMmapEngine";
try {
- FileMmapEngine fileMmapEngine = new FileMmapEngine(filePath, size);
+ ExclusiveMemoryMmapIOEngine fileMmapEngine = new ExclusiveMemoryMmapIOEngine(filePath, size);
for (int i = 0; i < 50; i++) {
int len = (int) Math.floor(Math.random() * 100);
long offset = (long) Math.floor(Math.random() * size % (size - len));
diff --git a/src/main/asciidoc/_chapters/architecture.adoc b/src/main/asciidoc/_chapters/architecture.adoc
index c250aa82d5e..9a5eba9e9ec 100644
--- a/src/main/asciidoc/_chapters/architecture.adoc
+++ b/src/main/asciidoc/_chapters/architecture.adoc
@@ -733,6 +733,8 @@ See configurations, sizings, current usage, time-in-the-cache, and even detail o
`LruBlockCache` is the original implementation, and is entirely within the Java heap.
`BucketCache` is optional and mainly intended for keeping block cache data off-heap, although `BucketCache` can also be a file-backed cache.
+ In file-backed we can either use it in the file mode or the mmaped mode.
+ We also have pmem mode where the bucket cache resides on the persistent memory device.
When you enable BucketCache, you are enabling a two tier caching system. We used to describe the
tiers as "L1" and "L2" but have deprecated this terminology as of hbase-2.0.0. The "L1" cache referred to an
diff --git a/src/main/asciidoc/_chapters/hbase-default.adoc b/src/main/asciidoc/_chapters/hbase-default.adoc
index f809f28fcc5..ccd5f6f45fb 100644
--- a/src/main/asciidoc/_chapters/hbase-default.adoc
+++ b/src/main/asciidoc/_chapters/hbase-default.adoc
@@ -1197,10 +1197,13 @@ When the size of a leaf-level, intermediate-level, or root-level
*`hbase.bucketcache.ioengine`*::
+
.Description
-Where to store the contents of the bucketcache. One of: onheap,
- offheap, or file. If a file, set it to file:PATH_TO_FILE.
- See https://hbase.apache.org/devapidocs/org/apache/hadoop/hbase/io/hfile/CacheConfig.html
- for more information.
+Where to store the contents of the bucketcache. One of: offheap,
+ file, files, mmap or pmem. If a file or files, set it to file(s):PATH_TO_FILE.
+ mmap means the content will be in an mmaped file. Use mmap:PATH_TO_FILE.
+ 'pmem' is bucket cache over a file on the persistent memory device.
+ Use pmem:PATH_TO_FILE.
+ See https://hbase.apache.org/devapidocs/org/apache/hadoop/hbase/io/hfile/CacheConfig.html
+ for more information.
+
.Default