Atmosphere websocket disconnected by Tomcat8 - tomcat8

Question

As my Apache Tomcat Server (8.0.39) has session timeout at 30 minutes (set in web.xml), I can't seem to get Atmosphere configured right to stop the webocket being disconnected after 30 minutes. Using runtime 2.4.8 and Javascript 2.3.5.
The message I get is:
Websocket closed, reason: This connection was established under an
authenticated HTTP session that has ended. - wasClean: true
Atmosphere: Firing onClose (closed case)
reasonPhrase:"maxReconnectOnClose reached"
I am using both client and server heartbeats. The server sends the heartbeat every 60 seconds, but this does not stop the Tomcat session from timing out at 30 minutes.
I've tried using MAX_INACTIVITY as outlined here:
https://github.com/Atmosphere/atmosphere/issues/2250
<init-param>
<param-name>org.atmosphere.cpr.AtmosphereInterceptor</param-name>
<param-value>o.a.interceptor.IdleResourceInterceptor</param-value>
</init-param>
<init-param>
<param-name>org.atmosphere.cpr.session.maxInactiveInterval</param-name>
<param-value>3600000</param-value>
</init-param>
<init-param>
<param-name>o.a.cpr.CometSupport.maxInactiveActivity</param-name>
<param-value>3600000</param-value>
</init-param>
But this is ignored as well and Tomcat closes the websocket.
Is there some way in Atmosphere to touch the Http Session and stop it from closing my websockets?
Basic setup:
#WebSocketHandlerService(path = "/async/chat", broadcasterCache =
UUIDBroadcasterCache.class)
public class ChatServer extends WebSocketHandlerAdapter {}
Javascript:
request.url = 'async/chat';
request.contentType = 'application/json';
request.transport = 'websocket';
request.fallbackTransport = 'websocket';
request.maxReconnectOnClose = 5;
request.enableProtocol = true;
request.trackMessageLength = true;
request.timeout = 3600000;
request.logLevel = 'debug';
web.xml:
<servlet>
<description>AtmosphereServlet</description>
<servlet-name>AtmosphereServlet</servlet-name>
<servlet-class>org.atmosphere.cpr.AtmosphereServlet</servlet-class>
<init-param>
<param-name>org.atmosphere.cpr.packages</param-name>
<param-value>atnf.jportal.websocket</param-value>
</init-param>
<init-param>
<param-name>org.atmosphere.cpr.AtmosphereInterceptor</param-name>
<param-value>o.a.client.TrackMessageSizeInterceptor</param-value>
</init-param>
<init-param>
<param-name>
o.a.i.HeartbeatInterceptor.clientHeartbeatFrequencyInSeconds
</param-name>
<param-value>120</param-value>
</init-param>
<async-supported>true</async-supported>
</servlet>
<servlet-mapping>
<servlet-name>AtmosphereServlet</servlet-name>
<url-pattern>/async/*</url-pattern>
</servlet-mapping>

Answer 1

By default, the Tomcat installation closed all sessions after a 30 minute period. With the atmosphere websocket implementation, this timeout will also cause all websockets to close, even though the client/server sends a heartbeat using HeartbeatInterceptor.
A mitigation plan was to simply set all sessions to have an infinite timeout in the application web.xml file, but this leaves stale sessions, which can number in the hundreds if not managed manually. After a bit of digging, it seems one can configure atmosphere to set session max inactive interval to -1 when an atmosphere connection exists.
In web.xml:
<init-param>
<param-name>org.atmosphere.cpr.removeSessionTimeout</param-name>
<param-value>true</param-value>
</init-param>
By itself, this does not enable sessions to have an infinite timeout, you also have to enable the listener
<listener>
<listener-class>org.atmosphere.cpr.SessionSupport</listener-class>
</listener>
With the above enabled, each session is assigned the following attribute/properties:
name: atmosphere.session.timeout.restorer
type: org.atmosphere.cpr.SessionTimeoutRestorer
value: SessionTimeoutRestorer[timeout=1800, requestCount=4]
Logging out of the application removes this attribute and assigns a timeout (30min tomcat default setting) to the remaining session*.
Spring Security closes the existing session and creates a new one (with timeout enabled).