how to limit the number of times Vaadin 14 tries to send heartbeat requests

Question

We have a Vaadin 14 (Flow) application which is fronted by an Apache reverse proxy that integrates with Gluu for authentication using OpenID (mod_auth_openidc).

This is generally working fine, except when users leave their browser open with the application idle for a long time, until the max session time of the OpenID session is reached. The problem is, at that point the Vaadin client keeps trying to send heartbeat requests. This, in combination with this mod_auth_openidc issue, results in state cookies piling up and reaching a limit so that the user has to close her browser before being able to re-login.

I've tried various things (unsuccessfully) in order to get the server to instruct the browser to visit a logout URL when a heartbeat request is received after session timeout (in combination with vaadin.closeIdleSessions=true), but even if it worked it wouldn't be a solution for other browser tabs that may also be open at that time and sending heartbeat requests.

What we really want is to limit the number of times the Vaadin client retries to send the heartbeat requests (say max 3 times) and then just stop sending requests (maybe display a message to re-login).

Is this possible in any way? The current workaround is to disable the heartbeats completely, but this doesn't seem ideal (Vaadin won't detect idle UIs).

Answer 1

The UI instance has a ReconnectDialogConfiguration which includes reconnectAttempts property to control how many times to re-try requests (including heartbeat requests). Default seems to be 10000.

In Vaadin 14 (LTS) this can be set using PageConfigurator.

In Vaadin 18 (latest release) this is done using AppShellConfigurator