How to remove Selenium Grid Node from grid if 'Failed to Connect'? - selenium

Question

I am using AWS EC2 instances to create a Selenium Grid. I have one instance acting as the Hub and other instances acting as nodes.
Once I terminate the nodes, they still remain in the grid for quite sometime (like 15-20 minutes) before being completely removed, therefore, the API is returning incorrect values:
For example, the API is returning:
"slotCounts": {
"free": 9,
"total": 10
},
But really, there are ONLY 4 slots total, because the other nodes are no longer connected. Is there a configuration setting that will remove the nodes from grid faster after there is no longer a connection?
I start the Hub like this:
java -jar selenium-server-standalone-3.141.59.jar -role hub -port 4444;
And the clients like this:
java -jar -Dwebdriver.chrome.driver=chromedriver selenium-server-standalone-3.141.59.jar -role node -hub http://10.0.1.119:4444/grid/register -browser browserName=chrome,maxInstances=2,version=latest,seleniumProtocol=WebDriver
The nodes do eventually disappear from the grid but only after they have been quit (by quit, I mean after the computer that runs the node has been shutdown) for quite awhile (maybe 10-20 mins).
I looked at this Stack Overflow question: SO
And I can't figure out if I need to set nodePolling, timeout, browsertimout or a combination of them?
Update:
I just tested it again, and after the computer that runs the nodes was shutdown, it took around 20-22 mins for the grid to reflect that in the API.

Answer 1

As per the Selenium Grid helptext:
-timeout, -sessionTimeout
<Integer> in seconds : Specifies the timeout before the server
automatically kills a session that hasn't had any activity in the last X
seconds. The test slot will then be released for another test to use.
This is typically used to take care of client crashes. For grid hub/node
roles, cleanUpCycle must also be set. If a node does not specify it, the
hub value will be used.
So once the nodes are terminated to remove them completely from the console you can configure either of the following parameters:
-timeout
java -jar -Dwebdriver.chrome.driver=chromedriver selenium-server-standalone-3.141.59.jar -role node -hub http://192.168.225.173:4444/grid/register -browser browserName=chrome,maxInstances=2 -timeout 2
-sessionTimeout:
java -jar -Dwebdriver.chrome.driver=chromedriver selenium-server-standalone-3.141.59.jar -role node -hub http://192.168.225.173:4444/grid/register -browser browserName=chrome,maxInstances=2 -sessionTimeout 3
cleanUpCycle:
java -jar -Dwebdriver.chrome.driver=chromedriver selenium-server-standalone-3.141.59.jar -role node -hub http://192.168.225.173:4444/grid/register -browser browserName=chrome,maxInstances=2 -cleanUpCycle 4
References
You can find a couple of relevant detailed discussions in:
Is there a way too prevent selenium automatically terminating idle sessions?