Friday, December 26, 2008

MOSS, now as WSRP Producer

Until now, the WSRP support in MOSS 2007 have been limited to acting as WSRP 1.1 client by using the built in web parts. With the recently released WSRP Toolkit for SharePoint you can produce WSRP conformant data producers from SharePoint lists and libraries. External portal platforms (e.g. BEA AquaLogic Portal, IBM WebSphere Portal, SAP NetWeaver Enterprise Portal etc.) can then render SharePoint data natively through their WSRP consumer portlets. The Toolkit is available now for download from the MSDN Code Gallery.

© Copyright 2008, Tomas Elfving

Wednesday, December 10, 2008

Hot deploy in a MOSS web farm means loosing session state

The problem
Manys blogs describe how to deploy new code to a MOSS farm, but I have so far not found any solution how to do this without affecting end-users' session state. The scenario is as follows:

Let's say you have 2 WFE's and a load balancer in front, the classic minimal MOSS-redundant arcitecture. You set the load balancer to direct all hits to WFE2 while deploying on WFE1. The user sessions on WFE1 that you are updating are thrown out. The sessions cannot be transfered to WFE2 as it is not running the same code.

Desired solution
What you really would like for your users is to continue running their sessions based on the "old" code on WFE1 until they are done. That could take hours until all remaining users are done.

The Weblogic solution
WebLogic has a feature for this called parallell deployment to eliminate downtime during EAR version upgrade. You can deploy the new version without stopping the existing application and once the new version deployed successfully you can switch over transparently from the old one to new one. MOSS have currently nothing similar to offer.
More info:

The severity of this problem obviously depends on the functionality of your site. For an e-commerce site the loss of user shopping baskets could mean significant business impact.

© Copyright 2008, Tomas Elfving