100% agreed on timing. I think 2.0 should be for the breaking aspect (losing the configurations) and then 2.1/2.2 we can start adding on the new features. I also like the idea of a migration tool. We can make a script that takes your airflow.cfg and converts that into a yaml file.
via Newton Mail [https://cloudmagic.com/k/d/mailapp?ct=dx&cv=10.0.50&pv=10.15.5&source=email_footer_2] On Wed, Aug 12, 2020 at 7:48 AM, Jarek Potiuk <jarek.pot...@polidea.com> wrote: Big +1. All the arguments are very appealing to me and simplifying the Kubernetes Executor down to YAML-configurable one seems like a no-brainer especially if we provide some migration tools. I've lost countless hours on debugging some configuration problems, simply because the relevant Kubernetes-related configuration was in the least expected place - i.e. airflow.cfg. YAML configuration. I am also a big fan of both 1. and 2. I've implemented a POC of queue-based multi-scheduler once but having it embedded as part of core Airflow rather than based it on queues (which are basically a Celery Executor concept) is I think much better approach. Both 1. and 2. are cool. Now - question about timing. If we decide to go that route - my view is that simplifying Kubernetes should be an Airflow 2.0 task - alongside more comprehensive tests (which will be much easier to write in this case). The new features/ideas 1. 2. for KE I think should come after that - when we release and stabilize 2.0. Sounds like great candidates for 2.1 to me. J. On Wed, Aug 12, 2020 at 4:24 PM Daniel Imberman <daniel.imber...@gmail.com> wrote: > Hello, fellow Airflowers! I hope you are all well in these trying times. > > > With the recent launch of Airflow 2.0 preparation, it now seems like a > good time to review the project's state and where we can fit in some > breaking changes that will improve the project for the future. > > > When we first created the KubernetesExecutor, we had two goals in mind. > The first goal was to improve the airflow Auto scaling story. Previously, > airflow users would have to manually provision celery workers, which could > lead to wasted resources or missed SLAs. The other goal was to introduce a > community that was not yet well versed in the Kubernetes API to the > Kubernetes system. > > > To ease the community's transition, we abstracted many of the complexities > of creating a Kubernetes object. We chose to offer a limited number of > configurations and keep much of the pod creation process internal to > airflow. In the short-term, this system lowered the barrier to entry. Over > time, however, this abstraction has become a nightmare of tech debt as the > Kubernetes API is expensive and constantly changing. > > > With this in mind, I think it's time for us to consider a more > straightforward approach that takes the complexity out of Airflow and > offers the full Kubernetes API to the airflow user. > > > What I'm proposing here is pretty straightforward. We remove all > Kubernetes pod creation configurations from the airflow.cfg and instead > offer only one way to use the KubernetesExecutor: with a YAML file. > > > We can easily supply all of the configurations to the KubernetesExecutor > by offering example YAMLs (git sync mode is just a sidecar and an init > container, DAG volumes are just an example volume and volume mount, etc.). > > > This system would simplify a user's ability to predict what a pod will > look like once it is launched by airflow. They will know it's a base pod > and will be able to simply modify the pod object using the executor config > and the pod mutation hook. > > > > > > > > This simplification could also lead to some pretty great new features in > the KubernetesExecutor > > > Idea 1: Picking a pod_template_file per-task > Along with the existing customization with the executor config, solely > relying on pod files can allow users to pick the pod template file that > they want to use as their base pod on a per-task basis. An Airflow engineer > could supply several pre-made templates for their data scientists to reduce > the amount of customization an airflow user would need to use. > > > Idea 2: Merging the KubernetesExecutor into the CeleryExecutor > One idea that we've been excited about recently has been the idea of > creating merged Celery and Kubernetes executor. This hybrid executor would > default to launching celery workers with KEDA and would have the option to > launch individual tasks using the Kubernetes executor when a user wants > isolation or customization. Simplifying the Kubernetes executor reduces the > number of fail-points that this merged executor would need to account for. > > > > What would we need to do to implement this? > The good news here is that the hard work has already been done! As of > AIRFLOW-5413 [https://issues.apache.org/jira/browse/AIRFLOW-5413] by > David Lum, airflow already has the ability to use base worker pods on a > template file. This would involve primarily code deletion and very little > new code. > > > Thank you for your time and I look forward to the community’s discussion. > > Daniel -- Jarek Potiuk Polidea <https://www.polidea.com/> | Principal Software Engineer M: +48 660 796 129 <+48660796129> [image: Polidea] <https://www.polidea.com/>
