Yea, barring something silly on my end, I've very rarely had a problem with deploying.
That said, if you want the "safest" way to deploy, in that you can easily rollback, then the best way would be to use an exploded directory deploy.
Basically, explode your EAR in to a directory, and deploy from that.
When you want to deploy a new version, explode that to a new directory, then undeploy the old version and redeploy the new version from the new directory. If you have problems, undeploy it again and redeploy from the original.
That's about as safe as it can get barring actual bugs.
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