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.

12 files changed, 220 insertions, 10 deletions

diff --git a/config-model-api/src/main/java/com/yahoo/config/model/api/ModelContext.java b/config-model-api/src/main/java/com/yahoo/config/model/api/ModelContext.java
index c406fa80434..86360d482a6 100644
--- a/config-model-api/src/main/java/com/yahoo/config/model/api/ModelContext.java
+++ b/config-model-api/src/main/java/com/yahoo/config/model/api/ModelContext.java
@@ -72,6 +72,12 @@ public interface ModelContext {
         double defaultTermwiseLimit();
 
         // TODO Revisit in May or June 2020
+        double threadPoolSizeFactor();
+
+        // TODO Revisit in May or June 2020
+        double queueSizeFactor();
+
+        // TODO Revisit in May or June 2020
         double defaultSoftStartSeconds();
 
         // TODO Revisit in May or June 2020
diff --git a/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java b/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
index 99225beba4f..d799af36c3b 100644
--- a/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
+++ b/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
@@ -43,6 +43,8 @@ public class TestProperties implements ModelContext.Properties {
     private double topKProbability = 1.0;
     private double defaultTermwiseLimit = 1.0;
     private double softStartSeconds = 0.0;
+    private double threadPoolSizeFactor = 0.0;
+    private double queueSizeFactor = 0.0;
     private Optional<EndpointCertificateSecrets> endpointCertificateSecrets = Optional.empty();
     private AthenzDomain athenzDomain;
 
@@ -65,6 +67,16 @@ public class TestProperties implements ModelContext.Properties {
     @Override public double defaultTermwiseLimit() { return defaultTermwiseLimit; }
 
     @Override
+    public double threadPoolSizeFactor() {
+        return threadPoolSizeFactor;
+    }
+
+    @Override
+    public double queueSizeFactor() {
+        return queueSizeFactor;
+    }
+
+    @Override
     public double defaultSoftStartSeconds() {
         return softStartSeconds;
     }
@@ -86,7 +98,15 @@ public class TestProperties implements ModelContext.Properties {
         this.softStartSeconds = softStartSeconds;
         return this;
     }
+    public TestProperties setThreadPoolSizeFactor(double threadPoolSizeFactor) {
+        this.threadPoolSizeFactor = threadPoolSizeFactor;
+        return this;
+    }
 
+    public TestProperties setQueueSizeFactor(double queueSizeFactor) {
+        this.queueSizeFactor = queueSizeFactor;
+        return this;
+    }
     public TestProperties setApplicationId(ApplicationId applicationId) {
         this.applicationId = applicationId;
         return this;
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java b/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java
index e59baf88422..29bb578a67b 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java
@@ -5,6 +5,7 @@ import com.yahoo.config.model.api.container.ContainerServiceType;
 import com.yahoo.config.model.producer.AbstractConfigProducer;
 import com.yahoo.config.provision.Flavor;
 import com.yahoo.container.bundle.BundleInstantiationSpecification;
+import com.yahoo.container.handler.ThreadpoolConfig;
 import com.yahoo.osgi.provider.model.ComponentModel;
 import com.yahoo.prelude.fastsearch.FS4ResourcePool;
 import com.yahoo.search.config.QrStartConfig;
@@ -15,7 +16,10 @@ import com.yahoo.vespa.model.container.component.Component;
  *
  * @author gjoranv
  */
-public final class ApplicationContainer extends Container implements QrStartConfig.Producer {
+public final class ApplicationContainer extends Container implements
+        QrStartConfig.Producer,
+        ThreadpoolConfig.Producer
+{
 
     private static final String defaultHostedJVMArgs = "-XX:+UseOSErrorReporting -XX:+SuppressFatalErrorMessage";
 
@@ -73,4 +77,16 @@ public final class ApplicationContainer extends Container implements QrStartConf
         return (parent instanceof ContainerCluster) && (((ContainerCluster)parent).getDocproc() != null);
     }
 
+    @Override
+    public void getConfig(ThreadpoolConfig.Builder builder) {
+        if (! (parent instanceof ContainerCluster)) return;
+        if ((getHostResource() == null) || getHostResource().getFlavor().isEmpty()) return;
+        ContainerCluster containerCluster = (ContainerCluster) parent;
+        if (containerCluster.getThreadPoolSizeFactor() <= 0.0) return;
+
+        NodeFlavorTuning flavorTuning = new NodeFlavorTuning(getHostResource().getFlavor().get())
+                .setThreadPoolSizeFactor(containerCluster.getThreadPoolSizeFactor())
+                .setQueueSizeFactor(containerCluster.getQueueSizeFactor());
+        flavorTuning.getConfig(builder);
+    }
 }
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/ContainerCluster.java b/config-model/src/main/java/com/yahoo/vespa/model/container/ContainerCluster.java
index 833f6688fbc..b35b7562704 100755
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/ContainerCluster.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/ContainerCluster.java
@@ -160,12 +160,18 @@ public abstract class ContainerCluster<CONTAINER extends Container>
     private String jvmGCOptions = null;
     private String environmentVars = null;
 
+    private final double threadPoolSizeFactor;
+    private final double queueSizeFactor;
+
 
     public ContainerCluster(AbstractConfigProducer<?> parent, String subId, String name, DeployState deployState) {
         super(parent, subId);
         this.name = name;
         this.isHostedVespa = stateIsHosted(deployState);
         this.zone = (deployState != null) ? deployState.zone() : Zone.defaultZone();
+        this.threadPoolSizeFactor = deployState.getProperties().threadPoolSizeFactor();
+        this.queueSizeFactor = deployState.getProperties().queueSizeFactor();
+
         componentGroup = new ComponentGroup<>(this, "component");
 
         addComponent(new StatisticsComponent());
@@ -186,6 +192,14 @@ public abstract class ContainerCluster<CONTAINER extends Container>
         addJaxProviders();
     }
 
+    public double getThreadPoolSizeFactor() {
+        return threadPoolSizeFactor;
+    }
+
+    public double getQueueSizeFactor() {
+        return queueSizeFactor;
+    }
+
     public void setZone(Zone zone) {
         this.zone = zone;
     }
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/NodeFlavorTuning.java b/config-model/src/main/java/com/yahoo/vespa/model/container/NodeFlavorTuning.java
index 67938b36fd9..f9b50d0e641 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/NodeFlavorTuning.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/NodeFlavorTuning.java
@@ -2,6 +2,7 @@
 package com.yahoo.vespa.model.container;
 
 import com.yahoo.config.provision.Flavor;
+import com.yahoo.container.handler.ThreadpoolConfig;
 import com.yahoo.search.config.QrStartConfig;
 
 /**
@@ -9,10 +10,26 @@ import com.yahoo.search.config.QrStartConfig;
  *
  * @author balder
  */
-public class NodeFlavorTuning implements QrStartConfig.Producer {
+public class NodeFlavorTuning implements
+        QrStartConfig.Producer,
+        ThreadpoolConfig.Producer
+{
 
     private final Flavor flavor;
 
+    public NodeFlavorTuning setThreadPoolSizeFactor(double threadPoolSizeFactor) {
+        this.threadPoolSizeFactor = threadPoolSizeFactor;
+        return this;
+    }
+
+    public NodeFlavorTuning setQueueSizeFactor(double queueSizeFactor) {
+        this.queueSizeFactor = queueSizeFactor;
+        return this;
+    }
+
+    private double threadPoolSizeFactor = 8.0;
+    private double queueSizeFactor = 8.0;
+
     NodeFlavorTuning(Flavor flavor) {
         this.flavor = flavor;
     }
@@ -22,4 +39,15 @@ public class NodeFlavorTuning implements QrStartConfig.Producer {
         builder.jvm.availableProcessors(Math.max(2, (int)Math.ceil(flavor.getMinCpuCores())));
     }
 
+    @Override
+    public void getConfig(ThreadpoolConfig.Builder builder) {
+        // Controls max number of concurrent requests per container
+        int workerThreads = Math.max(2, (int)Math.ceil(flavor.getMinCpuCores() * threadPoolSizeFactor));
+        builder.maxthreads(workerThreads);
+
+        // This controls your burst handling capability.
+        // 0 => No extra burst handling beyond you max concurrent requests (maxthreads).
+        // N => N times max concurrent requests as a buffer for handling bursts
+        builder.queueSize((int)(workerThreads * queueSizeFactor));
+    }
 }
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/container/ContainerClusterTest.java b/config-model/src/test/java/com/yahoo/vespa/model/container/ContainerClusterTest.java
index 33cf0635349..0f94df80421 100755
--- a/config-model/src/test/java/com/yahoo/vespa/model/container/ContainerClusterTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/container/ContainerClusterTest.java
@@ -9,9 +9,11 @@ import com.yahoo.config.model.deploy.DeployState;
 import com.yahoo.config.model.deploy.TestProperties;
 import com.yahoo.config.model.test.MockRoot;
 import com.yahoo.config.provision.Environment;
+import com.yahoo.config.provision.Flavor;
 import com.yahoo.config.provision.RegionName;
 import com.yahoo.config.provision.SystemName;
 import com.yahoo.config.provision.Zone;
+import com.yahoo.config.provisioning.FlavorsConfig;
 import com.yahoo.container.handler.ThreadpoolConfig;
 import com.yahoo.search.config.QrStartConfig;
 import com.yahoo.vespa.model.Host;
@@ -164,6 +166,8 @@ public class ContainerClusterTest {
         cluster.getConfig(tpBuilder);
         ThreadpoolConfig threadpoolConfig = new ThreadpoolConfig(tpBuilder);
         assertEquals(10, threadpoolConfig.maxthreads());
+        assertEquals(0, threadpoolConfig.queueSize());
+        assertEquals(0, threadpoolConfig.softStartSeconds(), 0);
     }
 
     @Test
@@ -213,10 +217,44 @@ public class ContainerClusterTest {
         cluster.getConfig(tpBuilder);
         ThreadpoolConfig threadpoolConfig = new ThreadpoolConfig(tpBuilder);
         assertEquals(500, threadpoolConfig.maxthreads());
+        assertEquals(0, threadpoolConfig.queueSize());
         assertEquals(300.0, threadpoolConfig.softStartSeconds(), 0.0);
     }
 
     @Test
+    public void requireThatPoolAndQueueCanNotBeControlledByPropertiesWhenNoFlavor() {
+        DeployState state = new DeployState.Builder().properties(new TestProperties()
+                    .setThreadPoolSizeFactor(8.5)
+                    .setQueueSizeFactor(13.3))
+                .build();
+        MockRoot root = new MockRoot("foo", state);
+        ApplicationContainerCluster cluster = createContainerCluster(root, false);
+        addContainer(root.deployLogger(), cluster, "c1", "host-c1");
+
+        ThreadpoolConfig.Builder tpBuilder = new ThreadpoolConfig.Builder();
+        cluster.getConfig(tpBuilder);
+        ThreadpoolConfig threadpoolConfig = new ThreadpoolConfig(tpBuilder);
+        assertEquals(500, threadpoolConfig.maxthreads());
+        assertEquals(0, threadpoolConfig.queueSize());
+        assertEquals(0.0, threadpoolConfig.softStartSeconds(), 0.0);
+    }
+
+    @Test
+    public void requireThatPoolAndQueueCanBeControlledByPropertiesAndFlavor() {
+        FlavorsConfig.Flavor.Builder flavorBuilder = new FlavorsConfig.Flavor.Builder().name("my_flavor").minCpuCores(3);
+        NodeFlavorTuning nodeFlavorTuning = new NodeFlavorTuning(new Flavor(new FlavorsConfig.Flavor(flavorBuilder)))
+                .setThreadPoolSizeFactor(13.3)
+                .setQueueSizeFactor(17.5);
+
+        ThreadpoolConfig.Builder tpBuilder = new ThreadpoolConfig.Builder();
+        nodeFlavorTuning.getConfig(tpBuilder);
+        ThreadpoolConfig threadpoolConfig = new ThreadpoolConfig(tpBuilder);
+        assertEquals(40, threadpoolConfig.maxthreads());
+        assertEquals(700, threadpoolConfig.queueSize());
+        assertEquals(0.0, threadpoolConfig.softStartSeconds(), 0.0);
+    }
+
+    @Test
     public void requireThatDefaultThreadPoolConfigIsSane() {
         MockRoot root = new MockRoot("foo");
         ApplicationContainerCluster cluster = createContainerCluster(root, false);
@@ -226,6 +264,7 @@ public class ContainerClusterTest {
         cluster.getConfig(tpBuilder);
         ThreadpoolConfig threadpoolConfig = new ThreadpoolConfig(tpBuilder);
         assertEquals(500, threadpoolConfig.maxthreads());
+        assertEquals(0, threadpoolConfig.queueSize());
         assertEquals(0.0, threadpoolConfig.softStartSeconds(), 0.0);
     }
 
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ModelContextImpl.java b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ModelContextImpl.java
index 2773659559b..0f141dee5b4 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ModelContextImpl.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ModelContextImpl.java
@@ -150,6 +150,8 @@ public class ModelContextImpl implements ModelContext {
         private final Optional<EndpointCertificateSecrets> endpointCertificateSecrets;
         private final double defaultTermwiseLimit;
         private final double defaultSoftStartSeconds;
+        private final double threadPoolSizeFactor;
+        private final double queueSizefactor;
         private final Optional<AthenzDomain> athenzDomain;
 
         public Properties(ApplicationId applicationId,
@@ -186,6 +188,10 @@ public class ModelContextImpl implements ModelContext {
                     .with(FetchVector.Dimension.APPLICATION_ID, applicationId.serializedForm()).value();
             defaultTopKprobability = Flags.DEFAULT_TOP_K_PROBABILITY.bindTo(flagSource)
                     .with(FetchVector.Dimension.APPLICATION_ID, applicationId.serializedForm()).value();
+            threadPoolSizeFactor = Flags.DEFAULT_THREADPOOL_SIZE_FACTOR.bindTo(flagSource)
+                    .with(FetchVector.Dimension.APPLICATION_ID, applicationId.serializedForm()).value();
+            queueSizefactor = Flags.DEFAULT_QUEUE_SIZE_FACTOR.bindTo(flagSource)
+                    .with(FetchVector.Dimension.APPLICATION_ID, applicationId.serializedForm()).value();
             this.athenzDomain = athenzDomain;
         }
 
@@ -238,8 +244,18 @@ public class ModelContextImpl implements ModelContext {
         @Override
         public double defaultTermwiseLimit() { return defaultTermwiseLimit; }
 
+        @Override
+        public double threadPoolSizeFactor() {
+            return threadPoolSizeFactor;
+        }
+
+        @Override
+        public double queueSizeFactor() {
+            return queueSizefactor;
+        }
+
         public double defaultSoftStartSeconds() {
-            return 0;
+            return defaultSoftStartSeconds;
         }
 
         @Override
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<>();
 
diff --git a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
index 76206996207..85d841e4bb0 100644
--- a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
+++ b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
@@ -150,7 +150,16 @@ public class Flags {
             "Default number of seconds that a soft start shall use",
             "Takes effect at redeployment",
             ZONE_ID, APPLICATION_ID);
-
+    public static final UnboundDoubleFlag DEFAULT_THREADPOOL_SIZE_FACTOR = defineDoubleFlag(
+            "default-threadpool-size-factor", 0.0,
+            "Default multiplication factor when computing maxthreads for main container threadpool based on available cores",
+            "Takes effect at redeployment",
+            ZONE_ID, APPLICATION_ID);
+    public static final UnboundDoubleFlag DEFAULT_QUEUE_SIZE_FACTOR = defineDoubleFlag(
+            "default-queue-size-factor", 0.0,
+            "Default multiplication factor when computing queuesize for burst handling",
+            "Takes effect at redeployment",
+            ZONE_ID, APPLICATION_ID);
     public static final UnboundDoubleFlag DEFAULT_TOP_K_PROBABILITY = defineDoubleFlag(
             "default-top-k-probability", 1.0,
             "Default probability that you will get the globally top K documents when merging many partitions.",