Expose server config, session queue and node as MBeans for JMX monitoring.

java/server/src/org/openqa/selenium/grid/node/BUILD.bazel

@@ -21,6 +21,7 @@ java_library(
         "//java/server/src/org/openqa/selenium/grid/security",
         "//java/server/src/org/openqa/selenium/grid/web",
         "//java/server/src/org/openqa/selenium/status",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         artifact("com.google.guava:guava"),
     ],
 )

java/server/src/org/openqa/selenium/grid/node/local/BUILD.bazel

@@ -25,6 +25,7 @@ java_library(
         "//java/server/src/org/openqa/selenium/grid/node/config",
         "//java/server/src/org/openqa/selenium/grid/security",
         "//java/server/src/org/openqa/selenium/grid/server",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         artifact("com.google.guava:guava"),
     ],
 )

java/server/src/org/openqa/selenium/grid/node/local/LocalNode.java

@@ -31,6 +31,7 @@
 import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.concurrent.Regularly;
 import org.openqa.selenium.events.EventBus;
+import org.openqa.selenium.grid.data.Availability;
 import org.openqa.selenium.grid.data.CreateSessionRequest;
 import org.openqa.selenium.grid.data.CreateSessionResponse;
 import org.openqa.selenium.grid.data.NodeDrainComplete;
@@ -53,6 +54,9 @@
 import org.openqa.selenium.remote.SessionId;
 import org.openqa.selenium.remote.http.HttpRequest;
 import org.openqa.selenium.remote.http.HttpResponse;
+import org.openqa.selenium.remote.server.jmx.JMXHelper;
+import org.openqa.selenium.remote.server.jmx.ManagedAttribute;
+import org.openqa.selenium.remote.server.jmx.ManagedService;
 import org.openqa.selenium.remote.tracing.AttributeKey;
 import org.openqa.selenium.remote.tracing.EventAttribute;
 import org.openqa.selenium.remote.tracing.EventAttributeValue;
@@ -91,6 +95,8 @@
 import static org.openqa.selenium.remote.http.Contents.string;
 import static org.openqa.selenium.remote.http.HttpMethod.DELETE;
 
+@ManagedService(objectName = "org.seleniumhq.grid:type=Node,name=LocalNode",
+  description = "Node running the webdriver sessions.")
 public class LocalNode extends Node {
 
   private static final Json JSON = new Json();
@@ -173,6 +179,8 @@ private LocalNode(
         }
       }
     }));
+
+    new JMXHelper().register(this);
   }
 
   @Override
@@ -181,11 +189,53 @@ public boolean isReady() {
   }
 
   @VisibleForTesting
+  @ManagedAttribute(name = "CurrentSessions")
   public int getCurrentSessionCount() {
     // It seems wildly unlikely we'll overflow an int
     return Math.toIntExact(currentSessions.size());
   }
 
+  @ManagedAttribute(name = "MaxSessions")
+  public int getMaxSessionCount() {
+    return maxSessionCount;
+  }
+
+  @ManagedAttribute(name = "Status")
+  public Availability getAvailability() {
+    return isDraining() ? DRAINING : UP;
+  }
+
+  @ManagedAttribute(name = "TotalSlots")
+  public int getTotalSlots() {
+    return factories.size();
+  }
+
+  @ManagedAttribute(name = "UsedSlots")
+  public long getUsedSlots() {
+    return factories.stream().filter(sessionSlot -> !sessionSlot.isAvailable()).count();
+  }
+
+  @ManagedAttribute(name = "Load")
+  public float getLoad() {
+    long inUse = factories.stream().filter(sessionSlot -> !sessionSlot.isAvailable()).count();
+    return inUse / (float) maxSessionCount * 100f;
+  }
+
+  @ManagedAttribute(name = "RemoteNodeUri")
+  public URI getExternalUri() {
+    return this.getUri();
+  }
+
+  @ManagedAttribute(name = "GridUri")
+  public URI getGridUri() {
+    return this.gridUri;
+  }
+
+  @ManagedAttribute(name = "NodeId")
+  public String getNodeId() {
+    return getId().toString();
+  }
+
   @Override
   public boolean isSupporting(Capabilities capabilities) {
     return factories.parallelStream().anyMatch(factory -> factory.test(capabilities));

java/server/src/org/openqa/selenium/grid/server/BUILD.bazel

@@ -20,6 +20,7 @@ java_library(
         "//java/server/src/org/openqa/selenium/grid/component",
         "//java/server/src/org/openqa/selenium/grid/config",
         "//java/server/src/org/openqa/selenium/grid/web",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         artifact("com.beust:jcommander"),
         artifact("com.google.guava:guava"),
         artifact("javax.servlet:javax.servlet-api"),

java/server/src/org/openqa/selenium/grid/server/BaseServerOptions.java

@@ -23,13 +23,18 @@
 import org.openqa.selenium.net.HostIdentifier;
 import org.openqa.selenium.net.NetworkUtils;
 import org.openqa.selenium.net.PortProber;
+import org.openqa.selenium.remote.server.jmx.JMXHelper;
+import org.openqa.selenium.remote.server.jmx.ManagedAttribute;
+import org.openqa.selenium.remote.server.jmx.ManagedService;
 
 import java.io.File;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Optional;
 import java.util.logging.Logger;
 
+@ManagedService(objectName = "org.seleniumhq.grid:type=Config,name=BaseServerConfig",
+    description = "Server config")
 public class BaseServerOptions {
 
   private static final String SERVER_SECTION = "server";
@@ -40,12 +45,14 @@ public class BaseServerOptions {
 
   public BaseServerOptions(Config config) {
     this.config = config;
+    new JMXHelper().register(this);
   }
 
   public Optional<String> getHostname() {
     return config.get(SERVER_SECTION, "hostname");
   }
 
+  @ManagedAttribute(name = "Port")
   public int getPort() {
     if (port == -1) {
       int newPort = config.getInt(SERVER_SECTION, "port")
@@ -61,6 +68,7 @@ public int getPort() {
     return port;
   }
 
+  @ManagedAttribute(name = "MaxServerThreads")
   public int getMaxServerThreads() {
     int count = config.getInt(SERVER_SECTION, "max-threads")
         .orElse(200);
@@ -72,6 +80,7 @@ public int getMaxServerThreads() {
     return count;
   }
 
+  @ManagedAttribute(name = "Uri")
   public URI getExternalUri() {
     // Assume the host given is addressable if it's been set
     String host = getHostname()

java/server/src/org/openqa/selenium/grid/sessionqueue/BUILD.bazel

@@ -20,6 +20,7 @@ java_library(
         "//java/server/src/org/openqa/selenium/grid/data",
         "//java/server/src/org/openqa/selenium/grid/log",
         "//java/server/src/org/openqa/selenium/status",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         artifact("com.google.guava:guava"),
     ],
 )

java/server/src/org/openqa/selenium/grid/sessionqueue/config/BUILD.bazel

@@ -6,11 +6,13 @@ java_library(
     srcs = glob(["*.java"]),
     visibility = [
         "//java/server/src/org/openqa/selenium/grid:__subpackages__",
+        "//java/server/test/org/openqa/selenium/grid:__subpackages__",
     ],
     deps = [
         "//java:auto-service",
         "//java/server/src/org/openqa/selenium/grid/config",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         artifact("com.beust:jcommander"),
         artifact("io.opentelemetry:opentelemetry-api"),
     ],

java/server/src/org/openqa/selenium/grid/sessionqueue/config/NewSessionQueueOptions.java

@@ -19,9 +19,14 @@
 
 import org.openqa.selenium.grid.config.Config;
 import org.openqa.selenium.grid.sessionqueue.NewSessionQueue;
+import org.openqa.selenium.remote.server.jmx.JMXHelper;
+import org.openqa.selenium.remote.server.jmx.ManagedAttribute;
+import org.openqa.selenium.remote.server.jmx.ManagedService;
 
 import java.time.Duration;
 
+@ManagedService(objectName = "org.seleniumhq.grid:type=Config,name=NewSessionQueueConfig",
+  description = "New session queue config")
 public class NewSessionQueueOptions {
 
   private static final String SESSIONS_QUEUE_SECTION = "sessionqueue";
@@ -35,10 +40,11 @@ public class NewSessionQueueOptions {
 
   public NewSessionQueueOptions(Config config) {
     this.config = config;
+    new JMXHelper().register(this);
   }
 
   public Duration getSessionRequestTimeout() {
-    int timeout = config.getInt(SESSIONS_QUEUE_SECTION, "session-request-timeout")
+    long timeout = config.getInt(SESSIONS_QUEUE_SECTION, "session-request-timeout")
       .orElse(DEFAULT_REQUEST_TIMEOUT);
 
     if (timeout <= 0) {
@@ -48,7 +54,7 @@ public Duration getSessionRequestTimeout() {
   }
 
   public Duration getSessionRequestRetryInterval() {
-    int interval = config.getInt(SESSIONS_QUEUE_SECTION, "session-retry-interval")
+    long interval = config.getInt(SESSIONS_QUEUE_SECTION, "session-retry-interval")
       .orElse(DEFAULT_RETRY_INTERVAL);
 
     if (interval <= 0) {
@@ -57,6 +63,16 @@ public Duration getSessionRequestRetryInterval() {
     return Duration.ofSeconds(interval);
   }
 
+  @ManagedAttribute(name = "RequestTimeoutSeconds")
+  public long getRequestTimeoutSeconds() {
+    return getSessionRequestTimeout().getSeconds();
+  }
+
+  @ManagedAttribute(name = "RetryIntervalSeconds")
+  public long getRetryIntervalSeconds() {
+    return getSessionRequestRetryInterval().getSeconds();
+  }
+
   public NewSessionQueue getSessionQueue() {
     return config
       .getClass(SESSIONS_QUEUE_SECTION, "implementation", NewSessionQueue.class,

java/server/src/org/openqa/selenium/grid/sessionqueue/local/BUILD.bazel

@@ -18,6 +18,7 @@ java_library(
         "//java/server/src/org/openqa/selenium/grid/server",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue/config",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         artifact("com.google.guava:guava"),
     ],
 )

java/server/src/org/openqa/selenium/grid/sessionqueue/local/LocalNewSessionQueue.java

@@ -29,6 +29,11 @@
 import org.openqa.selenium.grid.sessionqueue.config.NewSessionQueueOptions;
 import org.openqa.selenium.internal.Require;
 import org.openqa.selenium.remote.http.HttpRequest;
+
+import org.openqa.selenium.remote.server.jmx.JMXHelper;
+import org.openqa.selenium.remote.server.jmx.ManagedAttribute;
+import org.openqa.selenium.remote.server.jmx.ManagedService;
+
 import org.openqa.selenium.remote.tracing.AttributeKey;
 import org.openqa.selenium.remote.tracing.EventAttribute;
 import org.openqa.selenium.remote.tracing.EventAttributeValue;
@@ -50,6 +55,8 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+@ManagedService(objectName = "org.seleniumhq.grid:type=SessionQueue,name=LocalSessionQueue",
+  description = "New session queue")
 public class LocalNewSessionQueue extends NewSessionQueue {
 
   private static final Logger LOG = Logger.getLogger(LocalNewSessionQueue.class.getName());
@@ -65,6 +72,7 @@ public LocalNewSessionQueue(Tracer tracer, EventBus bus, Duration retryInterval,
     super(tracer, retryInterval, requestTimeout);
     this.bus = Require.nonNull("Event bus", bus);
     Runtime.getRuntime().addShutdownHook(shutdownHook);
+    new JMXHelper().register(this);
   }
 
   public static NewSessionQueue create(Config config) {
@@ -80,6 +88,17 @@ public boolean isReady() {
     return bus.isReady();
   }
 
+  @ManagedAttribute(name = "NewSessionQueueSize")
+  public int getQueueSize() {
+    Lock readLock = lock.readLock();
+    readLock.lock();
+    try {
+      return sessionRequests.size();
+    } finally {
+      readLock.unlock();
+    }
+  }
+
   @Override
   public boolean offerLast(HttpRequest request, RequestId requestId) {
     Require.nonNull("New Session request", request);

java/server/src/org/openqa/selenium/remote/server/jmx/BUILD.bazel

@@ -5,5 +5,7 @@ java_library(
     srcs = glob(["*.java"]),
     visibility = [
         "//java/server/src/org/openqa/selenium/grid/session:__pkg__",
+        "//java/server/src/org/openqa/selenium/grid:__subpackages__",
+        "//java/server/test/org/openqa/selenium/grid:__subpackages__",
     ],
 )

java/server/test/org/openqa/selenium/grid/router/BUILD.bazel

@@ -70,12 +70,14 @@ java_test_suite(
         "//java/server/src/org/openqa/selenium/grid/sessionmap/httpd",
         "//java/server/src/org/openqa/selenium/grid/sessionmap/local",
         "//java/server/src/org/openqa/selenium/grid/sessionmap/remote",
+        "//java/server/src/org/openqa/selenium/grid/sessionqueue/config",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue/httpd",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue/local",
         "//java/server/src/org/openqa/selenium/grid/sessionqueue/remote",
         "//java/server/src/org/openqa/selenium/grid/web",
         "//java/server/src/org/openqa/selenium/netty/server",
+        "//java/server/src/org/openqa/selenium/remote/server/jmx",
         "//java/server/test/org/openqa/selenium/grid/testing",
         artifact("com.google.guava:guava"),
         artifact("io.opentelemetry:opentelemetry-api"),