Continuous calling of vaadinServlet/PUSH url

Hi,

I had checked URLs getting call frequently and found that it is related to a long-poll connection being closed when the proxy intercepts the connection. Based on the traffic pattern observed
URL list that matches only the following URL:

vaadinServlet/PUSH

Query is why this URL pattern is getting called frequently if it is related to any further process completion . Can we refer to any documentation.