YARN-9121. Replace GpuDiscoverer.getInstance() to a readable object for easy access control. Contributed by Szilard Nemeth.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/resources/gpu/GpuResourceHandlerImpl.java

@@ -52,14 +52,17 @@ public class GpuResourceHandlerImpl implements ResourceHandler {
   private final GpuResourceAllocator gpuAllocator;
   private final CGroupsHandler cGroupsHandler;
   private final PrivilegedOperationExecutor privilegedOperationExecutor;
+  private final GpuDiscoverer gpuDiscoverer;
 
   public GpuResourceHandlerImpl(Context nmContext,
       CGroupsHandler cGroupsHandler,
-      PrivilegedOperationExecutor privilegedOperationExecutor) {
+      PrivilegedOperationExecutor privilegedOperationExecutor,
+      GpuDiscoverer gpuDiscoverer) {
     this.nmContext = nmContext;
     this.cGroupsHandler = cGroupsHandler;
     this.privilegedOperationExecutor = privilegedOperationExecutor;
-    gpuAllocator = new GpuResourceAllocator(nmContext);
+    this.gpuAllocator = new GpuResourceAllocator(nmContext);
+    this.gpuDiscoverer = gpuDiscoverer;
   }
 
   @Override
@@ -67,7 +70,7 @@ public class GpuResourceHandlerImpl implements ResourceHandler {
       throws ResourceHandlerException {
     List<GpuDevice> usableGpus;
     try {
-      usableGpus = GpuDiscoverer.getInstance().getGpusUsableByYarn();
+      usableGpus = gpuDiscoverer.getGpusUsableByYarn();
       if (usableGpus == null || usableGpus.isEmpty()) {
         String message = "GPU is enabled on the NodeManager, but couldn't find "
             + "any usable GPU devices, please double check configuration!";

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/ResourcePluginManager.java

@@ -34,6 +34,8 @@ import org.apache.hadoop.yarn.server.nodemanager.api.deviceplugin.DeviceRegister
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.deviceframework.DeviceMappingManager;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.deviceframework.DevicePluginAdapter;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.fpga.FpgaResourcePlugin;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.gpu.GpuDiscoverer;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.gpu.GpuNodeResourceUpdateHandler;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.gpu.GpuResourcePlugin;
 import org.apache.hadoop.yarn.util.resource.ResourceUtils;
 import org.slf4j.Logger;
@@ -96,7 +98,10 @@ public class ResourcePluginManager {
 
         ResourcePlugin plugin = null;
         if (resourceName.equals(GPU_URI)) {
-          plugin = new GpuResourcePlugin();
+          final GpuDiscoverer gpuDiscoverer = new GpuDiscoverer();
+          final GpuNodeResourceUpdateHandler updateHandler =
+              new GpuNodeResourceUpdateHandler(gpuDiscoverer);
+          plugin = new GpuResourcePlugin(updateHandler, gpuDiscoverer);
         } else if (resourceName.equals(FPGA_URI)) {
           plugin = new FpgaResourcePlugin();
         }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/gpu/GpuDiscoverer.java

@@ -58,11 +58,6 @@ public class GpuDiscoverer {
   // command should not run more than 10 sec.
   private static final int MAX_EXEC_TIMEOUT_MS = 10 * 1000;
   private static final int MAX_REPEATED_ERROR_ALLOWED = 10;
-  private static GpuDiscoverer instance;
-
-  static {
-    instance = new GpuDiscoverer();
-  }
 
   private Configuration conf = null;
   private String pathOfGpuBinary = null;
@@ -293,8 +288,4 @@ public class GpuDiscoverer {
   String getPathOfGpuBinary() {
     return pathOfGpuBinary;
   }
-
-  public static GpuDiscoverer getInstance() {
-    return instance;
-  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/gpu/GpuNodeResourceUpdateHandler.java

@@ -35,16 +35,20 @@ import static org.apache.hadoop.yarn.api.records.ResourceInformation.GPU_URI;
 public class GpuNodeResourceUpdateHandler extends NodeResourceUpdaterPlugin {
   private static final Logger LOG =
       LoggerFactory.getLogger(GpuNodeResourceUpdateHandler.class);
+  private final GpuDiscoverer gpuDiscoverer;
+
+  public GpuNodeResourceUpdateHandler(GpuDiscoverer gpuDiscoverer) {
+    this.gpuDiscoverer = gpuDiscoverer;
+  }
 
   @Override
   public void updateConfiguredResource(Resource res) throws YarnException {
     LOG.info("Initializing configured GPU resources for the NodeManager.");
 
-    List<GpuDevice> usableGpus = GpuDiscoverer.getInstance()
-            .getGpusUsableByYarn();
+    List<GpuDevice> usableGpus = gpuDiscoverer.getGpusUsableByYarn();
     if (usableGpus == null || usableGpus.isEmpty()) {
       String message = "GPU is enabled, " +
-              "but couldn't find any usable GPUs on the NodeManager!";
+          "but could not find any usable GPUs on the NodeManager!";
       LOG.error(message);
       // No gpu can be used by YARN.
       throw new YarnException(message);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/gpu/GpuResourcePlugin.java

@@ -18,7 +18,6 @@
 
 package org.apache.hadoop.yarn.server.nodemanager.containermanager.resourceplugin.gpu;
 
-import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.server.nodemanager.Context;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.privileged.PrivilegedOperationExecutor;
@@ -34,18 +33,23 @@ import org.apache.hadoop.yarn.server.nodemanager.webapp.dao.gpu.GpuDeviceInforma
 import org.apache.hadoop.yarn.server.nodemanager.webapp.dao.gpu.NMGpuResourceInfo;
 
 import java.util.List;
-import java.util.Map;
 
 public class GpuResourcePlugin implements ResourcePlugin {
+  private final GpuNodeResourceUpdateHandler resourceDiscoverHandler;
+  private final GpuDiscoverer gpuDiscoverer;
   private GpuResourceHandlerImpl gpuResourceHandler = null;
-  private GpuNodeResourceUpdateHandler resourceDiscoverHandler = null;
   private DockerCommandPlugin dockerCommandPlugin = null;
 
+  public GpuResourcePlugin(GpuNodeResourceUpdateHandler resourceDiscoverHandler,
+      GpuDiscoverer gpuDiscoverer) {
+    this.resourceDiscoverHandler = resourceDiscoverHandler;
+    this.gpuDiscoverer = gpuDiscoverer;
+  }
+
   @Override
   public synchronized void initialize(Context context) throws YarnException {
-    resourceDiscoverHandler = new GpuNodeResourceUpdateHandler();
-    GpuDiscoverer.getInstance().initialize(context.getConf());
-    dockerCommandPlugin =
+    this.gpuDiscoverer.initialize(context.getConf());
+    this.dockerCommandPlugin =
         GpuDockerCommandPluginFactory.createGpuDockerCommandPlugin(
             context.getConf());
   }
@@ -56,7 +60,7 @@ public class GpuResourcePlugin implements ResourcePlugin {
       PrivilegedOperationExecutor privilegedOperationExecutor) {
     if (gpuResourceHandler == null) {
       gpuResourceHandler = new GpuResourceHandlerImpl(context, cGroupsHandler,
-          privilegedOperationExecutor);
+          privilegedOperationExecutor, gpuDiscoverer);
     }
 
     return gpuResourceHandler;
@@ -77,9 +81,9 @@ public class GpuResourcePlugin implements ResourcePlugin {
   }
 
   @Override
-  public NMResourceInfo getNMResourceInfo() throws YarnException {
+  public synchronized NMResourceInfo getNMResourceInfo() throws YarnException {
     GpuDeviceInformation gpuDeviceInformation =
-        GpuDiscoverer.getInstance().getGpuDeviceInformation();
+        gpuDiscoverer.getGpuDeviceInformation();
     GpuResourceAllocator gpuResourceAllocator =
         gpuResourceHandler.getGpuAllocator();
     List<GpuDevice> totalGpus = gpuResourceAllocator.getAllowedGpusCopy();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/resources/gpu/TestGpuResourceHandler.java

@@ -71,6 +71,7 @@ public class TestGpuResourceHandler {
   private GpuResourceHandlerImpl gpuResourceHandler;
   private NMStateStoreService mockNMStateStore;
   private ConcurrentHashMap<ContainerId, Container> runningContainersMap;
+  private GpuDiscoverer gpuDiscoverer;
 
   @Before
   public void setup() {
@@ -89,8 +90,9 @@ public class TestGpuResourceHandler {
     runningContainersMap = new ConcurrentHashMap<>();
     when(nmctx.getContainers()).thenReturn(runningContainersMap);
 
+    gpuDiscoverer = new GpuDiscoverer();
     gpuResourceHandler = new GpuResourceHandlerImpl(nmctx, mockCGroupsHandler,
-        mockPrivilegedExecutor);
+        mockPrivilegedExecutor, gpuDiscoverer);
   }
 
   @Test
@@ -98,7 +100,7 @@ public class TestGpuResourceHandler {
     Configuration conf = new YarnConfiguration();
     conf.set(YarnConfiguration.NM_GPU_ALLOWED_DEVICES, "0:0");
 
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     gpuResourceHandler.bootstrap(conf);
     verify(mockCGroupsHandler, times(1)).initializeCGroupController(
@@ -162,7 +164,7 @@ public class TestGpuResourceHandler {
       throws Exception {
     Configuration conf = new YarnConfiguration();
     conf.set(YarnConfiguration.NM_GPU_ALLOWED_DEVICES, "0:0,1:1,2:3,3:4");
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     gpuResourceHandler.bootstrap(conf);
     Assert.assertEquals(4,
@@ -251,7 +253,7 @@ public class TestGpuResourceHandler {
       throws Exception {
     Configuration conf = new YarnConfiguration();
     conf.set(YarnConfiguration.NM_GPU_ALLOWED_DEVICES, "0:0,1:1,2:3,3:4");
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     gpuResourceHandler.bootstrap(conf);
     Assert.assertEquals(4,
@@ -280,7 +282,7 @@ public class TestGpuResourceHandler {
   public void testAllocationWithoutAllowedGpus() throws Exception {
     Configuration conf = new YarnConfiguration();
     conf.set(YarnConfiguration.NM_GPU_ALLOWED_DEVICES, " ");
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     try {
       gpuResourceHandler.bootstrap(conf);
@@ -315,7 +317,7 @@ public class TestGpuResourceHandler {
   public void testAllocationStored() throws Exception {
     Configuration conf = new YarnConfiguration();
     conf.set(YarnConfiguration.NM_GPU_ALLOWED_DEVICES, "0:0,1:1,2:3,3:4");
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     gpuResourceHandler.bootstrap(conf);
     Assert.assertEquals(4,
@@ -361,9 +363,9 @@ public class TestGpuResourceHandler {
 
     GpuResourceHandlerImpl gpuNULLStateResourceHandler =
         new GpuResourceHandlerImpl(nmnctx, mockCGroupsHandler,
-        mockPrivilegedExecutor);
+        mockPrivilegedExecutor, gpuDiscoverer);
 
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     gpuNULLStateResourceHandler.bootstrap(conf);
     Assert.assertEquals(4,
@@ -383,7 +385,7 @@ public class TestGpuResourceHandler {
   public void testRecoverResourceAllocation() throws Exception {
     Configuration conf = new YarnConfiguration();
     conf.set(YarnConfiguration.NM_GPU_ALLOWED_DEVICES, "0:0,1:1,2:3,3:4");
-    GpuDiscoverer.getInstance().initialize(conf);
+    gpuDiscoverer.initialize(conf);
 
     gpuResourceHandler.bootstrap(conf);
     Assert.assertEquals(4,