presto-resource-group-managers/src/main/java/io/prestosql/plugin/resourcegroups/db/DbResourceGroupConfigurationManager.java/DbResourceGroupConfigurationManager/disableGroup
class DbResourceGroupConfigurationManager:    private synchronized void disableGroup(ResourceGroup group)
    {
        // Disable groups that are removed from the db
        group.setHardConcurrencyLimit(0);
        group.setMaxQueuedQueries(0);
    }