Optimizations

Sometimes, Ansible feels slow, mainly if you have a very long list of tasks to execute and/or if you have huge amount of machines. This feeling is actually more than just a feeling. There are multiple reasons for this, and ways to avoid it, we are going to look at three of those.

Pipelining

One of the reason why Ansible is slow by default is that for every module execution and for every host, Ansible will perform the following actions:

• SSH handshake

• Execute the task

• Close the SSH connection

As you can see, this means that if you have 10 tasks to be executed on a single remote server, Ansible will open (and close) the connection 10 times. Since the SSH protocol is an encrypted protocol, this makes the SSH handshake an even longer process, since the two parts have to negotiate the ciphers every single time.

Ansible allows us to reduce the execution time drastically by initiating the connections at the beginning of the playbook and keeping them alive for the whole execution so that it...