Selenium Grid: org.openqa.selenium.WebDriverException: Error forwarding the new session Empty pool of VM for setup Capabilities

There are multiple problems with your code. In a nutshell, you are hardcoding a lot of the OS platform information only in your Desired Capabilities object that you are using to create the WebDriver but the Grid Hub is not having those changes.

I also noticed that your code base is trying to talk to a hub running in a different port but your hub is running in a different port.

I also noticed that your test code is not waiting for the Node to be registered to the hub. I have as a quick hack added a sleep to facilitate that, but you can employ sophisticated mechanisms such as polling the hub to see if the node is registered or not etc.,

You need to create a patch file with the below git diff contents and then you can apply it to your codebase.

Here's a git diff that you can apply to your project to fix the problem

From 7d718cea160e7feac2fab8526f8578553d697426 Mon Sep 17 00:00:00 2001
From: Krishnan Mahadevan <Krishnan.Mahadevan>
Date: Sat, 26 Jun 2021 19:46:33 +0530
Subject: [PATCH] Changes needed

---
 .../java/WebdriverBase/GridDriverManager.java     | 15 +++++----------
 .../java/WebdriverBase/HubNodeConfiguration.java  | 12 +++++++++---
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/main/java/WebdriverBase/GridDriverManager.java b/src/main/java/WebdriverBase/GridDriverManager.java
index 58a8052..4102ac3 100644
--- a/src/main/java/WebdriverBase/GridDriverManager.java
+++ b/src/main/java/WebdriverBase/GridDriverManager.java
@@ -96,7 +96,7 @@ public class GridDriverManager {
        }
        if (browserType.equalsIgnoreCase("Chrome")) {
            try {
-               System.setProperty("webdriver.chrome.driver","/Users/rishikhanna/Documents/cucumber/shopping/Driver/chromedriver");
+//             System.setProperty("webdriver.chrome.driver","/Users/rishikhanna/Documents/cucumber/shopping/Driver/chromedriver");
            } catch (Exception e) {
                e.printStackTrace();
            }
@@ -112,9 +112,8 @@ public class GridDriverManager {
 //            chromePrefs.put("profile.default_content_settings.popups", 0);
 //            ChromeOptions options = new ChromeOptions();
 //            options.setExperimentalOption("prefs", chromePrefs);
-            capabilities.setBrowserName("chrome");
-            capabilities.setPlatform(Platform.MOJAVE);
-            capabilities.setVersion("91.0.4472.114");
+
+            capabilities.merge(DesiredCapabilities.chrome());
             capabilities.setCapability(CapabilityType.ACCEPT_SSL_CERTS, true);
           //  capabilities.setCapability(ChromeOptions.CAPABILITY, options);
        }
@@ -130,9 +129,6 @@ public class GridDriverManager {
        if (platformType.equalsIgnoreCase("WINDOWS")) {
            capabilities.setPlatform(Platform.WINDOWS);
        }
-       if (platformType.equalsIgnoreCase("MAC")) {
-           capabilities.setPlatform(Platform.MOJAVE);
-       }
 
        //capabilities.setVersion(getValFromJson(jsonObject,"version"));
        return capabilities;
@@ -149,7 +145,7 @@ public class GridDriverManager {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
-       setDriver("chrome", "WINDOWS");
+       setDriver("chrome", "MAC");
        return threadLocalDriver.get();
    }
 
@@ -159,8 +155,7 @@ public class GridDriverManager {
        {
            try {
                HubNodeConfiguration.configureServer();
-               System.setProperty("webdriver.chrome.driver","/Users/rishikhanna/Documents/cucumber/shopping/Driver/chromedriver");
-               threadLocalDriver.set(new RemoteWebDriver(new URL("http://localhost:9090/wd/hub"),capabilities));
+               threadLocalDriver.set(new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"),capabilities));
                threadLocalDriver.get().manage().timeouts().implicitlyWait(10,TimeUnit.SECONDS);
            } catch (MalformedURLException e) {
                e.printStackTrace();
diff --git a/src/main/java/WebdriverBase/HubNodeConfiguration.java b/src/main/java/WebdriverBase/HubNodeConfiguration.java
index 174b216..2725bba 100644
--- a/src/main/java/WebdriverBase/HubNodeConfiguration.java
+++ b/src/main/java/WebdriverBase/HubNodeConfiguration.java
@@ -4,6 +4,7 @@ import java.io.File;
 import java.net.MalformedURLException;
 import java.net.URL;
 
+import java.util.concurrent.TimeUnit;
 import org.openqa.grid.common.GridRole;
 import org.openqa.grid.common.RegistrationRequest;
 import org.openqa.grid.internal.utils.SelfRegisteringRemote;
@@ -30,10 +31,10 @@ public class HubNodeConfiguration {
        myHub.start();
 
        GridNodeConfiguration gridNodeConfig = new GridNodeConfiguration();
-       gridNodeConfig.hub = "http://127.0.0.1:4444/grid/register";
-       gridNodeConfig.host = "xxxx"; //my ip address
+       gridNodeConfig.hub = "http://localhost:4444";
+       gridNodeConfig.host = "localhost"; //my ip address
        gridNodeConfig.port = 5566;
-       gridNodeConfig.role = "webdriver";
+       gridNodeConfig.role = "node";
        RegistrationRequest req = RegistrationRequest.build(gridNodeConfig);
        req.getConfiguration();
        req.validate();
@@ -44,6 +45,11 @@ public class HubNodeConfiguration {
        remote.startRemoteServer();
        remote.startRegistrationProcess();
 
+       try {
+           TimeUnit.SECONDS.sleep(10);
+       } catch (InterruptedException e) {
+           e.printStackTrace();
+       }
        System.out.println("Node Registered to Hub..............");
    }
 }
-- 
2.24.3 (Apple Git-128)+GitX