[zimbatm]

I have used Ansible 6 months ago and it felt slow.

The biggest issue which is intrinsic to the model is that each task is executed sequentially across all the target hosts. It makes it's behaviour easy to understand but it also makes each step as slow as the slowest host.

Another issue that might be fixed now is that each task is essentially a script uploaded to the target and then executed locally. Unfortunately at the time the scripts weren't cached properly so N invocation of the same task would mean N uploads of the same script.

That being said it's really simple to use and I recommend it if you don't have an existing infrastructure management system. Ansible fits in well as an orchestration tool.

[mpdehaan2]

Hi zimbatm,

Please read the tuning article on the blog for sure. It's definitely not slow and we have folks updating 5000 servers in 5 minutes. (Yes, really!) ControlPersist and the like are key, and we'd be happy to help discuss options for you.

As for sequentially, set --forks to control parallelism. Steps are executed in order, but that's true of all CMS systems.

[zimbatm]

> It's definitely not slow and we have folks updating 5000 servers in 5 minutes. (Yes, really!) ControlPersist and the like are key, and we'd be happy to help discuss options for you.

It's good but I wouldn't describe this as fast, it should be possible to increase the performance by another order of magnitude with some optimisation. Web servers can easily serve 5000 request per second even when SSL is involved, why couldn't Ansible do the same ?

After enabling ControlPersist, the next optimisation is to run Ansible in the same datacenter. Latency is a killer when deploying to us-east-1 from Europe.

> Steps are executed in order, but that's true of all CMS systems.

It's true on a single host (although puppet's and salt's ordering is not guaranteed). Ansible also orders across all the hosts. If you have tasks A->B->C, ansible will first run A on all the hosts and collect the results before moving to the next step. Each step is thus as slow as the slowest execution.