make Global stupid pool cache size configurable

common/src/main/java/io/druid/collections/StupidPool.java

@@ -38,11 +38,24 @@ public class StupidPool<T>
 
   private final Queue<T> objects = new ConcurrentLinkedQueue<>();
 
+  //note that this is just the max entries in the cache, pool can still create as many buffers as needed.
+  private final int objectsCacheMaxCount;
+
   public StupidPool(
       Supplier<T> generator
   )
   {
     this.generator = generator;
+    this.objectsCacheMaxCount = Integer.MAX_VALUE;
+  }
+
+  public StupidPool(
+      Supplier<T> generator,
+      int objectsCacheMaxCount
+  )
+  {
+    this.generator = generator;
+    this.objectsCacheMaxCount = objectsCacheMaxCount;
   }
 
   public ResourceHolder<T> take()
@@ -80,8 +93,12 @@ public class StupidPool<T>
         log.warn(new ISE("Already Closed!"), "Already closed");
         return;
       }
-      if (!objects.offer(object)) {
-        log.warn(new ISE("Queue offer failed"), "Could not offer object [%s] back into the queue", object);
+      if (objects.size() < objectsCacheMaxCount) {
+        if (!objects.offer(object)) {
+          log.warn(new ISE("Queue offer failed"), "Could not offer object [%s] back into the queue", object);
+        }
+      } else {
+        log.debug("cache num entries is exceeding max limit [%s]", objectsCacheMaxCount);
       }
     }
 

docs/content/configuration/broker.md

@@ -55,6 +55,7 @@ The broker uses processing configs for nested groupBy queries. And, optionally,
 |Property|Description|Default|
 |--------|-----------|-------|
 |`druid.processing.buffer.sizeBytes`|This specifies a buffer size for the storage of intermediate results. The computation engine in both the Historical and Realtime nodes will use a scratch buffer of this size to do all of their intermediate computations off-heap. Larger values allow for more aggregations in a single pass over the data while smaller values can require more passes depending on the query that is being executed.|1073741824 (1GB)|
+|`druid.processing.buffer.poolCacheMaxCount`|processing buffer pool caches the buffers for later use, this is the maximum count cache will grow to. note that pool can create more buffers than it can cache if necessary.|Integer.MAX_VALUE|
 |`druid.processing.formatString`|Realtime and historical nodes use this format string to name their processing threads.|processing-%s|
 |`druid.processing.numThreads`|The number of processing threads to have available for parallel processing of segments. Our rule of thumb is `num_cores - 1`, which means that even under heavy load there will still be one core available to do background tasks like talking with ZooKeeper and pulling down segments. If only one core is available, this property defaults to the value `1`.|Number of cores - 1 (or 1)|
 |`druid.processing.columnCache.sizeBytes`|Maximum size in bytes for the dimension value lookup cache. Any value greater than `0` enables the cache. It is currently disabled by default. Enabling the lookup cache can significantly improve the performance of aggregators operating on dimension values, such as the JavaScript aggregator, or cardinality aggregator, but can slow things down if the cache hit rate is low (i.e. dimensions with few repeating values). Enabling it may also require additional garbage collection tuning to avoid long GC pauses.|`0` (disabled)|

docs/content/configuration/historical.md

@@ -53,6 +53,7 @@ Druid uses Jetty to serve HTTP requests.
 |Property|Description|Default|
 |--------|-----------|-------|
 |`druid.processing.buffer.sizeBytes`|This specifies a buffer size for the storage of intermediate results. The computation engine in both the Historical and Realtime nodes will use a scratch buffer of this size to do all of their intermediate computations off-heap. Larger values allow for more aggregations in a single pass over the data while smaller values can require more passes depending on the query that is being executed.|1073741824 (1GB)|
+|`druid.processing.buffer.poolCacheMaxCount`|processing buffer pool caches the buffers for later use, this is the maximum count cache will grow to. note that pool can create more buffers than it can cache if necessary.|Integer.MAX_VALUE|
 |`druid.processing.formatString`|Realtime and historical nodes use this format string to name their processing threads.|processing-%s|
 |`druid.processing.numThreads`|The number of processing threads to have available for parallel processing of segments. Our rule of thumb is `num_cores - 1`, which means that even under heavy load there will still be one core available to do background tasks like talking with ZooKeeper and pulling down segments. If only one core is available, this property defaults to the value `1`.|Number of cores - 1 (or 1)|
 |`druid.processing.columnCache.sizeBytes`|Maximum size in bytes for the dimension value lookup cache. Any value greater than `0` enables the cache. It is currently disabled by default. Enabling the lookup cache can significantly improve the performance of aggregators operating on dimension values, such as the JavaScript aggregator, or cardinality aggregator, but can slow things down if the cache hit rate is low (i.e. dimensions with few repeating values). Enabling it may also require additional garbage collection tuning to avoid long GC pauses.|`0` (disabled)|

processing/src/main/java/io/druid/query/DruidProcessingConfig.java

@@ -31,6 +31,12 @@ public abstract class DruidProcessingConfig extends ExecutorServiceConfig implem
     return 1024 * 1024 * 1024;
   }
 
+  @Config({"druid.computation.buffer.poolCacheMaxCount", "${base_path}.buffer.poolCacheMaxCount"})
+  public int poolCacheMaxCount()
+  {
+    return Integer.MAX_VALUE;
+  }
+
   @Override @Config(value = "${base_path}.numThreads")
   public int getNumThreads()
   {

processing/src/test/java/io/druid/query/DruidProcessingConfigTest.java

@@ -0,0 +1,66 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets 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 io.druid.query;
+
+import com.google.common.collect.ImmutableMap;
+import com.metamx.common.config.Config;
+import org.junit.Assert;
+import org.junit.Test;
+import org.skife.config.ConfigurationObjectFactory;
+
+import java.util.Properties;
+
+/**
+ */
+public class DruidProcessingConfigTest
+{
+
+  @Test
+  public void testDeserialization() throws Exception
+  {
+    ConfigurationObjectFactory factory = Config.createFactory(new Properties());
+
+    //with defaults
+    DruidProcessingConfig config = factory.build(DruidProcessingConfig.class);
+
+    Assert.assertEquals(1024 * 1024 * 1024, config.intermediateComputeSizeBytes());
+    Assert.assertEquals(Integer.MAX_VALUE, config.poolCacheMaxCount());
+    Assert.assertTrue(config.getNumThreads() < Runtime.getRuntime().availableProcessors());
+    Assert.assertEquals(0, config.columnCacheSizeBytes());
+    Assert.assertFalse(config.isFifo());
+
+    //with non-defaults
+    Properties props = new Properties();
+    props.setProperty("druid.processing.buffer.sizeBytes", "1");
+    props.setProperty("druid.processing.buffer.poolCacheMaxCount", "1");
+    props.setProperty("druid.processing.numThreads", "5");
+    props.setProperty("druid.processing.columnCache.sizeBytes", "1");
+    props.setProperty("druid.processing.fifo", "true");
+
+    factory = Config.createFactory(props);
+    config = factory.buildWithReplacements(DruidProcessingConfig.class, ImmutableMap.of("base_path", "druid.processing"));
+
+    Assert.assertEquals(1, config.intermediateComputeSizeBytes());
+    Assert.assertEquals(1, config.poolCacheMaxCount());
+    Assert.assertEquals(5, config.getNumThreads());
+    Assert.assertEquals(1, config.columnCacheSizeBytes());
+    Assert.assertTrue(config.isFifo());
+  }
+}

server/src/main/java/io/druid/guice/DruidProcessingModule.java

@@ -125,7 +125,7 @@ public class DruidProcessingModule implements Module
       log.info(e.getMessage());
     }
 
-    return new OffheapBufferPool(config.intermediateComputeSizeBytes());
+    return new OffheapBufferPool(config.intermediateComputeSizeBytes(), config.poolCacheMaxCount());
   }
 
 

server/src/main/java/io/druid/offheap/OffheapBufferPool.java

@@ -31,7 +31,7 @@ public class OffheapBufferPool extends StupidPool<ByteBuffer>
 {
   private static final Logger log = new Logger(OffheapBufferPool.class);
 
-  public OffheapBufferPool(final int computationBufferSize)
+  public OffheapBufferPool(final int computationBufferSize, final int cacheMaxCount)
   {
     super(
         new Supplier<ByteBuffer>()
@@ -47,7 +47,8 @@ public class OffheapBufferPool extends StupidPool<ByteBuffer>
             );
             return ByteBuffer.allocateDirect(computationBufferSize);
           }
-        }
+        },
+        cacheMaxCount
     );
   }
 }