Let size of thread pool and Q follow number of cores on the machine where it is running.

If auto detected num worker threads will use number of #cores * 4, quesize will use #numWorkers * 4.
No changes of the default value in this commit.

4 files changed, 68 insertions, 6 deletions

diff --git a/container-core/abi-spec.json b/container-core/abi-spec.json
index 6d683c53984..82d34d88b99 100644
--- a/container-core/abi-spec.json
+++ b/container-core/abi-spec.json
@@ -171,6 +171,7 @@
       "public void <init>()",
       "public void <init>(com.yahoo.container.handler.ThreadpoolConfig)",
       "public com.yahoo.container.handler.ThreadpoolConfig$Builder maxthreads(int)",
+      "public com.yahoo.container.handler.ThreadpoolConfig$Builder queueSize(int)",
       "public com.yahoo.container.handler.ThreadpoolConfig$Builder maxThreadExecutionTimeSeconds(int)",
       "public com.yahoo.container.handler.ThreadpoolConfig$Builder softStartSeconds(double)",
       "public final boolean dispatchGetConfig(com.yahoo.config.ConfigInstance$Producer)",
@@ -210,6 +211,7 @@
       "public static java.lang.String getDefVersion()",
       "public void <init>(com.yahoo.container.handler.ThreadpoolConfig$Builder)",
       "public int maxthreads()",
+      "public int queueSize()",
       "public int maxThreadExecutionTimeSeconds()",
       "public double softStartSeconds()"
     ],
diff --git a/container-core/src/main/java/com/yahoo/container/handler/ThreadPoolProvider.java b/container-core/src/main/java/com/yahoo/container/handler/ThreadPoolProvider.java
index b427a58c9b7..0e786cfbc8f 100644
--- a/container-core/src/main/java/com/yahoo/container/handler/ThreadPoolProvider.java
+++ b/container-core/src/main/java/com/yahoo/container/handler/ThreadPoolProvider.java
@@ -10,6 +10,7 @@ import com.yahoo.container.protect.ProcessTerminator;
 import com.yahoo.jdisc.Metric;
 
 import java.util.Map;
+import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ExecutorService;
@@ -33,17 +34,30 @@ public class ThreadPoolProvider extends AbstractComponent implements Provider<Ex
 
     private final ExecutorServiceWrapper threadpool;
 
+    private static BlockingQueue<Runnable> createQ(int queueSize, int maxThreads) {
+        return (queueSize == 0)
+                ? new SynchronousQueue<>(false)
+                : (queueSize < 0)
+                    ? new ArrayBlockingQueue<>(maxThreads*4)
+                    : new ArrayBlockingQueue<>(queueSize);
+    }
+
+    private static int computeThreadPoolSize(int maxNumThreads) {
+        return (maxNumThreads <= 0)
+                ? Runtime.getRuntime().availableProcessors() * 4
+                : maxNumThreads;
+    }
     @Inject
     public ThreadPoolProvider(ThreadpoolConfig threadpoolConfig, Metric metric) {
         this(threadpoolConfig, metric, new ProcessTerminator());
     }
 
     public ThreadPoolProvider(ThreadpoolConfig threadpoolConfig, Metric metric, ProcessTerminator processTerminator) {
+        int maxNumThreads = computeThreadPoolSize(threadpoolConfig.maxthreads());
         WorkerCompletionTimingThreadPoolExecutor executor =
-                new WorkerCompletionTimingThreadPoolExecutor(threadpoolConfig.maxthreads(),
-                                                             threadpoolConfig.maxthreads(),
+                new WorkerCompletionTimingThreadPoolExecutor(maxNumThreads, maxNumThreads,
                                                              0L, TimeUnit.SECONDS,
-                                                             new SynchronousQueue<>(false),
+                                                             createQ(threadpoolConfig.queueSize(), maxNumThreads),
                                                              ThreadFactoryFactory.getThreadFactory("threadpool"),
                                                              metric);
         // Prestart needed, if not all threads will be created by the fist N tasks and hence they might also
@@ -87,8 +101,9 @@ public class ThreadPoolProvider extends AbstractComponent implements Provider<Ex
     /**
      * A service executor wrapper which emits metrics and
      * shuts down the vm when no workers are available for too long to avoid containers lingering in a blocked state.
+     * Package private for testing
      */
-    private final static class ExecutorServiceWrapper extends ForwardingExecutorService {
+    final static class ExecutorServiceWrapper extends ForwardingExecutorService {
 
         private final WorkerCompletionTimingThreadPoolExecutor wrapped;
         private final Metric metric;
@@ -160,8 +175,11 @@ public class ThreadPoolProvider extends AbstractComponent implements Provider<Ex
 
     }
 
-    /** A thread pool executor which maintains the last time a worker completed */
-    private final static class WorkerCompletionTimingThreadPoolExecutor extends ThreadPoolExecutor {
+    /**
+     *  A thread pool executor which maintains the last time a worker completed
+     *  package private for testing
+     **/
+    final static class WorkerCompletionTimingThreadPoolExecutor extends ThreadPoolExecutor {
 
         private static final String UNHANDLED_EXCEPTIONS_METRIC = "jdisc.thread_pool.unhandled_exceptions";
 
diff --git a/container-core/src/main/resources/configdefinitions/threadpool.def b/container-core/src/main/resources/configdefinitions/threadpool.def
index 9bb9badd9b5..abc60f9f06d 100644
--- a/container-core/src/main/resources/configdefinitions/threadpool.def
+++ b/container-core/src/main/resources/configdefinitions/threadpool.def
@@ -2,8 +2,16 @@
 
 namespace=container.handler
 
+## Num ber of thread in the thread pool
+## Setting it to 0 or negative number will cause it to be set to #cores * 4
 maxthreads int default=500
 
+## max queue size
+## There can be queueSize + maxthreads requests inflight concurrently
+## The container will start replying 503
+## Negative value will cause it to set to maxthreads*4
+queueSize int default=0
+
 # The max time the container tolerates having no threads available before it shuts down to
 # get out of a bad state. This should be set a bit higher than the expected max execution
 # time of each request when in a state of overload, i.e about "worst case execution time*2"
diff --git a/container-core/src/test/java/com/yahoo/container/handler/ThreadPoolProviderTestCase.java b/container-core/src/test/java/com/yahoo/container/handler/ThreadPoolProviderTestCase.java
index 918863f6dda..761ed40763c 100644
--- a/container-core/src/test/java/com/yahoo/container/handler/ThreadPoolProviderTestCase.java
+++ b/container-core/src/test/java/com/yahoo/container/handler/ThreadPoolProviderTestCase.java
@@ -5,6 +5,7 @@ import static org.junit.Assert.fail;
 
 import java.util.concurrent.Executor;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.ThreadPoolExecutor;
 
 import com.yahoo.container.protect.ProcessTerminator;
 import org.junit.Ignore;
@@ -58,6 +59,39 @@ public class ThreadPoolProviderTestCase {
         fail("Pool did not reject tasks after shutdown.");
     }
 
+    private ThreadPoolExecutor createPool(int maxThreads, int queueSize) {
+        ThreadpoolConfig config = new ThreadpoolConfig(new ThreadpoolConfig.Builder().maxthreads(maxThreads).queueSize(queueSize));
+        ThreadPoolProvider provider = new ThreadPoolProvider(config, Mockito.mock(Metric.class));
+        ThreadPoolProvider.ExecutorServiceWrapper wrapper = (ThreadPoolProvider.ExecutorServiceWrapper) provider.get();
+        ThreadPoolProvider.WorkerCompletionTimingThreadPoolExecutor executor = (ThreadPoolProvider.WorkerCompletionTimingThreadPoolExecutor)wrapper.delegate();
+        return executor;
+    }
+
+    @Test
+    public void testThatThreadPoolSizeFollowsConfig() {
+        ThreadPoolExecutor executor = createPool(3, 9);
+        assertEquals(3, executor.getMaximumPoolSize());
+        assertEquals(9, executor.getQueue().remainingCapacity());
+    }
+    @Test
+    public void testThatThreadPoolSizeAutoDetected() {
+        ThreadPoolExecutor executor = createPool(0, 0);
+        assertEquals(Runtime.getRuntime().availableProcessors()*4, executor.getMaximumPoolSize());
+        assertEquals(0, executor.getQueue().remainingCapacity());
+    }
+    @Test
+    public void testThatQueueSizeAutoDetected() {
+        ThreadPoolExecutor executor = createPool(3, -1);
+        assertEquals(3, executor.getMaximumPoolSize());
+        assertEquals(executor.getMaximumPoolSize()*4, executor.getQueue().remainingCapacity());
+    }
+    @Test
+    public void testThatThreadPoolSizeAndQueueSizeAutoDetected() {
+        ThreadPoolExecutor executor = createPool(0, -1);
+        assertEquals(Runtime.getRuntime().availableProcessors()*4, executor.getMaximumPoolSize());
+        assertEquals(executor.getMaximumPoolSize()*4, executor.getQueue().remainingCapacity());
+    }
+
     private class FlipIt implements Runnable {
         public final Receiver<Boolean> didItRun = new Receiver<>();