appium: Unable to pool the devices on selenium grid

The problem

I am unable to pool the devices on selenium grid for parallel testing. I have 2 real mobile devices connected to my grid and i want the grid to pick a device based on availablity. I do not want to always run on a particular device so I do not want to provide deviceName capability and i am using cucumber to run my tests so parallel testing is possible when the tests instances are tiggered from multiple sources (like different machines same time).

I want this setup to be working in gitlab pipelines for branches where multiple test instances are triggered with code changes and they could be parallel.

Node 1:

maxSession: 1

capabilities: Capabilities {browserName: Chrome, deviceName: ad0717021c344ef24b, maxInstances: 1, platform: ANDROID, platformName: Android, seleniumProtocol: WebDriver, server:CONFIG_UUID: bf2dc302-da0c-4361-a186-5c0..., version: 9.1}

Node 2

maxSession: 1

capabilities: Capabilities {browserName: Chrome, deviceName: V3XDU18129002649, maxInstances: 1, platform: ANDROID, platformName: Android, seleniumProtocol: WebDriver, server:CONFIG_UUID: b832a0de-43c8-4101-9e63-91c..., version: 9.1}

Commands to launch appium nodes

1. appium --session-override --nodeconfig path/nodeconfig1.json -p 4728 --bootstrap-port 2255
2. appium --session-override --nodeconfig path/nodeconfig2.json -p 4729 --bootstrap-port 2256

Environment

Appium - 1.10.1 selenium - 3.141.59

Link to Appium logs

 1) Error in custom provider, org.openqa.selenium.SessionNotCreatedException: A new session could not be created. Details: The desiredCapabilities object was not valid for the following reason(s): 'deviceName' can't be blank
    Build info: version: '3.141.59', revision: 'e82be7d358', time: '2018-11-14T08:17:03'
    System info: host: 'mahesh-thuma', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'amd64', os.version: '4.15.0-48-generic', java.version: '1.8.0_181'
    Driver info: driver.version: RemoteWebDriver
    remote stacktrace: SessionNotCreatedError: A new session could not be created. Details: The desiredCapabilities object was not valid for the following reason(s): 'deviceName' can't be blank

Code To Reproduce Issue

private fun getAndroidDriver(grid_url: String): RemoteWebDriver{
        val caps = DesiredCapabilities()
        caps.setCapability("platform", "Android")
        caps.setCapability("platformName", "Android")
        caps.setCapability("deviceName","")
        caps.setCapability("browserName","Chrome")
        caps.setCapability("automationName","UiAutomator")
       
   return RemoteWebDriver(java.net.URL(grid_url), caps)
    }