DevForce 2010: Push Notification on Load Balanced servers

Push Notification on Load Balanced servers

Printed From: IdeaBlade
Category: DevForce
Forum Name: DevForce 2010
Forum Discription: For .NET 4.0
URL: http://www.ideablade.com/forum/forum_posts.asp?TID=3064
Printed Date: 01-May-2026 at 8:36am

Topic: Push Notification on Load Balanced servers

Posted By: JamesM
Subject: Push Notification on Load Balanced servers
Date Posted: 27-Oct-2011 at 8:37am

We are using v6.0.6.0

I have a couple questions on how the BOS operates its Notification Service when the BOS resides on 2 or more servers in a load balanced configuration.

Does the BOSs share its notification subscribers automatically with other BOSs in a load balanced environment?

Is there a way to force the BOSs to share notification subscribers if its not automatic?

For extra information: I am using a push notification that is fired from a EntityServerSaveInterceptor when a specific field on an Entity is changed when saving.

Thank you,

James

Replies:

Posted By: sbelini
Date Posted: 27-Oct-2011 at 3:36pm

Hi James,

Unfortunately, in a load balanced environment BOSes do not share notification subscribers.

DevForce's Push feature uses WCF duplex communication support where the server maintains session information for each client. This does not scale to a load balanced environment.

Our Push notification also maintains its own “server affinity” in keeping a list of subscribed clients.

We have a feature request to address this issue.

In the meantime you could implement your custom pub-sub service using Azure Service Bus ( http://msdn.microsoft.com/en-us/library/dd628757.aspx - http://msdn.microsoft.com/en-us/library/dd628757.aspx ) and/or the Publish-Subscribe Framework from IDesign ( http://idesign.net/idesign/DesktopDefault.aspx?tabindex=5&tabid=11 - http://idesign.net/idesign/DesktopDefault.aspx?tabindex=5&tabid=11 ).

Regards,

Silvio.

Posted By: GeorgeB
Date Posted: 04-Nov-2011 at 4:22am

Hi Silvio

Currently we can't use the DevForce push notification in Azure (unless we stick to one server instance).

This feature request has been outstanding for a quite a while. Will we see it in the near future?

We bought a new DF load balancing license but without the push notification it was a waste.

George

Posted By: ting
Date Posted: 07-Nov-2011 at 1:08pm

Hi George,

Correct, because we can't control server affinity in Azure, push notification won't work with a multi-instance Azure deployment. (However, it should be fine with other providers/deployments where you can turn on session-aware load balancing.) For this to work in Azure, we'll have to redesign push to use another mechanism, so this won't be available in the near or mid-term. Sorry for the bad news. We can credit your account if you want to remove the Data Center feature from your license.

Ting