Package com.vaadin.kubernetes.starter.ui

Class RollingUpdateHandler

java.lang.Object

com.vaadin.kubernetes.starter.ui.RollingUpdateHandler

All Implemented Interfaces:

com.vaadin.flow.server.VaadinServiceInitListener, Serializable, EventListener

Direct Known Subclasses:

ClusterSupport

public class RollingUpdateHandler
extends Object
implements com.vaadin.flow.server.VaadinServiceInitListener

Handles rolling updates for Vaadin applications running in a cluster.

When the ingress controller or gateway sets the update version header on requests to the current (old) version, and its value differs from the configured application version, a notification is shown prompting the user to switch to the new version. When the user accepts, the sticky session cookie is removed and the session is invalidated, so that the next request is routed to a pod running the new version.

Since:

3.0

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
RollingUpdateHandler(String appVersion, String stickySessionCookieName, String updateVersionHeaderName)	Creates a new RollingUpdateHandler instance.

Method Summary

Modifier and Type	Method	Description
void	serviceInit(com.vaadin.flow.server.ServiceInitEvent serviceInitEvent)
void	setSwitchVersionListener(SwitchVersionListener listener)	Register the global version switch listener.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RollingUpdateHandler

public RollingUpdateHandler(String appVersion,
 String stickySessionCookieName,
 String updateVersionHeaderName)

Creates a new RollingUpdateHandler instance.

Parameters:

appVersion - the application version. When the update version header value differs from this version, a notification is shown prompting the user to switch to the new version. If null, rolling update version detection is disabled.

stickySessionCookieName - the name of the cookie used by the ingress controller or gateway implementation for sticky sessions. This must match the cookie name configured in the infrastructure routing traffic to the application. When the user accepts a version switch, this cookie is removed so that the next request is no longer pinned to the old pod.

updateVersionHeaderName - the name of the HTTP request header used to detect a new application version during rolling updates. The ingress controller or gateway sets this header on requests to the current version with the new version as its value.

See Also:

• KubernetesKitProperties.getAppVersion()
• KubernetesKitProperties.getStickySessionCookieName()
• KubernetesKitProperties.getUpdateVersionHeaderName()

Method Details

setSwitchVersionListener

public void setSwitchVersionListener(SwitchVersionListener listener)

Register the global version switch listener. If set to null the current session and the sticky cluster cookie are removed without any version switch condition check.

Parameters:

listener - the listener to register.

serviceInit

public void serviceInit(com.vaadin.flow.server.ServiceInitEvent serviceInitEvent)

Specified by:

serviceInit in interface com.vaadin.flow.server.VaadinServiceInitListener