I had to complete a disaster recovery project this week. We do this annually for one of our clients (yay for preparedness!) for one of their ColdFusion sites. I've got a run book and all that and was prepared to reinstall ColdFusion and copy in their EAR to redeploy the application. Until I had a conversation with a coworker: Him> Did they restore your data yet? Me> Yep, I'm just getting ready to reinstall ColdFusion and- Him> Re-install? Isn't everything already there? Me> Well, yeah, but. Wait... huh. I bet I could just run the jrunsvc command, and..

So it turns out, if you don't need search, .NET, LiveCycle or ODBC services, you can just restore ColdFusion from a a backup to your file system. All you really need (minus those other pieces) is to run the jrunsvc command to install a new ColdFusion service in the the services console and to run the wsconfig.jar to connect IIS to JRun (or, if you restore the website from a file, all of that is already there). My runbook went from something like 30 steps down to about 4. Color me happy. And when you think about it, it makes sense. Since it's all built atop Java (minus the other services) there's no reason to go through the installer. You can probably install those other components but I don't really need them, so I don't care to find out how at present. But still, this is a handy little tid bit.

For almost three years now we've been running ColdFusion (well, really JRun) session based replication and failover on all of our hosted ColdFusion environs. Things were great! And then, we let google in the door to index our content. Things went from "great", to "why is this always down??". I spent far too much time looking at JVM settings, JRun settings, etc., but never really came up with a concrete answer as to what was happening. Ultimately, we'd see a deluge of errors about the failure of session replication in the log files and a complete breaking of failover and sometimes even the JRun -> IIS connector.

Whilst searching for the session replication errors, I came across Sean Corfields postings across various blogs that replication just does not scale well, and that it remains a broken feature. Up until a few months ago, I'd argue this to be untrue. However, it appears that replication works... if you can manage to keep the amount of crap you throw into shared memory scopes down to a minimum.

It's been 4 days since I've disabled session replication, and my servers have remained standing for an equal amount of time. We've been getting indexed by google (and others), and things are sailing along with nary a blip. Next stop, creating a guide for users that want/need session based failover that can be accomplished in code. Otherwise known as, "Help me Sean Corfield, you're my only hope!" ;).