Cancel container activation onBeforeUnload

When a user starts a container (for instance by clicking a link) and rapidly closes the tab, the proxy gets activated and it continues to live until heartbeat-timeout is reached.
I have a very large heartbeat timeout, as I rely on the API within R to stop the containers (onSessionEnded()). As, by closing the tab, the user does not start a shiny session, the R code for reaching the API is not executed.
Therefore, I can have several unused containers using RAM unnecessarily during hours.

Would it be possible to cancel the proxy activation, eg. when the users closes the browser’s tab?

Another possibility would be to rely on heartbeat mechanism (if no heartbeat is received within the first minute following the start of the container, shinyproxy stops it).

Here is the code related to this (line 174 of file from ContainerProxy). Would you be interested in a pull request?

if (lastHeartbeat == null) {
	if (currentTimestamp - proxy.getStartupTimestamp() > 60000){"Releasing proxy without Heartbeat [spec: %s] [id: %s]", proxy.getSpec().getId(), proxy.getId()));
		proxyService.stopProxy(proxy, true, true);
	lastHeartbeat = proxy.getStartupTimestamp();


1 Like