@Override
  public void propertyChange(PropertyChangeEvent event) {

    // Validate the source of this event
    if (!(event.getSource() instanceof Context)) {
      return;
    }

    // Process a relevant property change
    if (event.getPropertyName().equals("sessionTimeout")) {
      try {
        int interval = (Integer) event.getNewValue();
        if (interval < RegionConfiguration.DEFAULT_MAX_INACTIVE_INTERVAL) {
          getLogger().warn("The configured session timeout of " + interval
              + " minutes is invalid. Using the original value of " + event.getOldValue()
              + " minutes.");
          interval = (Integer) event.getOldValue();
        }
        // StandardContext.setSessionTimeout passes -1 if the configured timeout
        // is 0; otherwise it passes the value set in web.xml. If the interval
        // parameter equals the default, set the max inactive interval to the
        // default (no expiration); otherwise set it in seconds.
        setMaxInactiveInterval(interval == RegionConfiguration.DEFAULT_MAX_INACTIVE_INTERVAL
            ? RegionConfiguration.DEFAULT_MAX_INACTIVE_INTERVAL : interval * 60);
      } catch (NumberFormatException e) {
        getLogger()
            .error(sm.getString("standardManager.sessionTimeout", event.getNewValue().toString()));
      }
    }
  }
Process property change events from our associated Context.
<p>
Part of this method implementation was taken from StandardManager. The sessionTimeout can be
changed in the web.xml which is processed after the context.xml. The context (and the default
session timeout) would already have been set in this Manager. This is the way to get the new
session timeout value specified in the web.xml.
<p>
The precedence order for setting the session timeout value is:
<ol>
<li>the max inactive interval is set based on the Manager defined in the context.xml
<li>the max inactive interval is then overwritten by the value of the Context's session timeout
when setContainer is called
<li>the max inactive interval is then overwritten by the value of the session-timeout specified
in the web.xml (if any)
</ol>

@param event The property change event that has occurred
extensions/geode-modules/src/main/java/org/apache/geode/modules/session/catalina/DeltaSessionManager.java