MCollective alternative?

Solution 1:

One compelling alternative is Salt. Parallel/distributed execution using ZeroMQ as the communications backend, so it maintains its own message queue instead of requiring ActiveMQ or RabbitMQ.

From the description:

Salt uses public keys for authentication with the master daemon, then uses faster AES encryption for payload communication, this means that authentication and encryption are also built into Salt.

Solution 2:

Its perfectly possible to secure MCollective, you can assign each user their own MQ authentication details etc and theres various nice SSL plugins.

What problem exactly worries you with MCollective? What do you want out of an alternative? There's various similar applications but none which duplicate MCollective - all have various ins and outs depending on what you want.

Examples include Func, Fabric, perhaps Control Tier and Capistrano.