Make the number of jobs in the worker configurable via an option

PiperOrigin-RevId: 161505952

3 files changed, 50 insertions, 3 deletions

diff --git a/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/BUILD b/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/BUILD
index 7e85b240e0..60d443338a 100644
--- a/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/BUILD
+++ b/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/BUILD
@@ -25,6 +25,7 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib:unix",
         "//src/main/java/com/google/devtools/build/lib:util",
         "//src/main/java/com/google/devtools/build/lib:vfs",
+        "//src/main/java/com/google/devtools/build/lib/actions",
         "//src/main/java/com/google/devtools/build/lib/remote",
         "//src/main/java/com/google/devtools/common/options",
         "//src/main/protobuf:option_filters_java_proto",
diff --git a/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/ExecutionServer.java b/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/ExecutionServer.java
index 034ff9ddc5..ec8dc956d0 100644
--- a/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/ExecutionServer.java
+++ b/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/ExecutionServer.java
@@ -85,9 +85,7 @@ final class ExecutionServer extends ExecutionImplBase {
   private final RemoteWorkerOptions workerOptions;
   private final SimpleBlobStoreActionCache cache;
   private final ConcurrentHashMap<String, ListenableFuture<ActionResult>> operationsCache;
-  private final ListeningExecutorService executorService =
-      MoreExecutors.listeningDecorator(
-          new ThreadPoolExecutor(0, 8, 1000, TimeUnit.SECONDS, new LinkedBlockingQueue<>()));
+  private final ListeningExecutorService executorService;
 
   public ExecutionServer(
       Path workPath,
@@ -100,6 +98,13 @@ final class ExecutionServer extends ExecutionImplBase {
     this.workerOptions = workerOptions;
     this.cache = cache;
     this.operationsCache = operationsCache;
+    this.executorService =
+        MoreExecutors.listeningDecorator(
+            new ThreadPoolExecutor(
+                1, workerOptions.jobs,  // always have one thread available, and use at most jobs
+                1000, TimeUnit.SECONDS, // shut down idle threads after 1000 seconds
+                // TODO(ulfjack): We need to reject work eventually.
+                new LinkedBlockingQueue<>())); // no blocking, we can always take more
   }
 
   @Override
diff --git a/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/RemoteWorkerOptions.java b/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/RemoteWorkerOptions.java
index e8bc12a781..b66e07b11b 100644
--- a/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/RemoteWorkerOptions.java
+++ b/src/tools/remote_worker/src/main/java/com/google/devtools/build/remote/RemoteWorkerOptions.java
@@ -14,9 +14,12 @@
 
 package com.google.devtools.build.remote;
 
+import com.google.devtools.build.lib.actions.LocalHostCapacity;
+import com.google.devtools.common.options.Converters.RangeConverter;
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionDocumentationCategory;
 import com.google.devtools.common.options.OptionsBase;
+import com.google.devtools.common.options.OptionsParsingException;
 import com.google.devtools.common.options.proto.OptionFilters.OptionEffectTag;
 import java.util.List;
 
@@ -116,4 +119,42 @@ public class RemoteWorkerOptions extends OptionsBase {
     help = "When using sandboxing, block network access for running actions."
   )
   public boolean sandboxingBlockNetwork;
+
+  @Option(
+    name = "jobs",
+    defaultValue = "auto",
+    converter = JobsConverter.class,
+    category = "build_worker",
+    documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
+    effectTags = {OptionEffectTag.UNKNOWN},
+    help =
+        "The maximum number of concurrent jobs to run. \"auto\" means to use a reasonable value"
+            + " derived from the machine's hardware profile (e.g. the number of processors)."
+            + " Values above " + MAX_JOBS + " are not allowed."
+  )
+  public int jobs;
+
+  private static final int MAX_JOBS = 16384;
+
+  /** Converter for jobs: [0, MAX_JOBS] or "auto". */
+  public static class JobsConverter extends RangeConverter {
+    public JobsConverter() {
+      super(0, MAX_JOBS);
+    }
+
+    @Override
+    public Integer convert(String input) throws OptionsParsingException {
+      if (input.equals("auto")) {
+        int autoJobs = (int) Math.ceil(LocalHostCapacity.getLocalHostCapacity().getCpuUsage());
+        return Math.min(autoJobs, MAX_JOBS);
+      } else {
+        return super.convert(input);
+      }
+    }
+
+    @Override
+    public String getTypeDescription() {
+      return "\"auto\" or " + super.getTypeDescription();
+    }
+  }
 }