[Fab-user] Revert deployments

[Miguel A. Lamy]

Hi all,

I am evaluating Fabric and a I'm bit lost sorry... I think I'm putting dumb 
question. 

I want to deploy Java Web application into several servers. In the past I used 
some shell scripts that stoped
myservers, rsynced my app to the servers, backuped the databases (Mysql, 
SqlServer and Oracle) and started
the application server (tipical Jboss and Oracle). I use ssh in all servers 
with public keys.

I was doing the deployment  server by server and sometimes the process didn't 
run as expected and I have
crashs during the startup of the application because of some program errors or 
inconsistency in the databases.

So I thought may be I can use some tool out there that simplify that work and 
revert my process with no
pain...

I read some documentation from Fabric site and from the github.com but still 
don't know how can I run
myscripts in a way that can "detect" errors in deployment and run some rollback 
code that reverts errors
during the deployment.

I understand that I can use variables to store command result status and define 
rollback commands that can be
executed but my question is... can Fabric "detect" errors and automatically 
execute rollback functions in
case of some trouble ?

I want to deploy several servers and not be worried if one server didn't 
deployed correctly at 2.00AM and the
application server didn't start because of that failure. That server should 
automatically recover from that
bad deploy, revert to the previous status so in the morning I can analyse the 
errors and correct that errors
not worried that users can't run my application because of that failure.
 
I'd appreciate any help given :-)

(Sorry for my poor english)

Miguel Lamy