The Appfabric Service Bus

Recently I came across a very interesting article which describes what the Appfabric service bus is all about. Check it out here!

BizTalk Hotfixes and Service Packs – How this affects availability?

A BizTalk environment might have many applications running. It becomes really important that these apps remain online when updates are being made to BizTalk server especially when apps are mission critical.

The question about availability has been put forward to me many times and this is a common dilemma among various hosting companies. While there are workarounds to some scenarios, not all cases can go without bringing the server offline for a period of time while it is being patched.

Lets looks at some cases below:

BizTalk Server

Patching BizTalk

  • If fix contain *.sql (as in it updates the DB) then the IIS/hosts across all servers has to be stopped state before executing the update. This is where the DR site comes in handy. A simple approach to this is:
    • Failover to the DR site
    • Apply SP/hotfixes to the live site
    • Failover to the live site
    • Apply SP/hotfixes to the DR site
  • If the fix does not contain *.sql runtime on each server needs to be restarted (this can be applied on server by server bases).

Deploying Applications

  • Existing Applications

    If you cannot take existing applications offline (doesn’t affect the rest of the environment) then you can deploy side by side versions. See thisarticle for details.

  • New Applications

    1. When deploying applications to new hosts, there is no impact to existing ones and this will not affect your environment’s availability.

    2. If deploying applications to existing hosts (hosting other applications), a host restart is required. Also, this has to be applied on server-by-server basis (take a single server offline, deploy the application then bring it back up).

SQL Server

When installing a service pack on SQL cluster, the following practice can be followed (see link) – which applies to SQL clusters.