The Nomad Autoscaler is an autoscaling daemon for Nomad, architectured around plug-ins to allow for easy extensibility in terms of supported metrics sources, scaling targets and scaling algorithms.
This project is in the early stages of development and is supplied without guarantees and subject to change without warning
Known issues and limitations:
- there is currently a limited number of supported APMs, this will be addressed but limits the usability
The Nomad Autoscaler currently supports:
-
Horizontal Application Autoscaling: The process of automatically controlling the number of instances of an application to have sufficient work throughput to meet service-level agreements (SLA). In Nomad, horizontal application autoscaling can be achieved by modifying the number of allocations in a task group based on the value of a relevant metric, such as CPU and memory utilization or number of open connections.
-
Horizontal Cluster Autoscaling: The process of adding or removing Nomad clients from a cluster to ensure there is an appropriate amount of cluster resource for the scheduled applications. This is achieved by interacting with remote providers to start or terminate new Nomad clients based on metrics such as the remaining free schedulable CPU or memory.
The autoscaler relies on Nomad APIs that were introduced in Nomad 0.11-beta1, some of which have been changed during the beta. The compatibility requirements are as follows:
| Autoscaler Version | Nomad Version |
|---|---|
| 0.0.1-techpreview1 | 0.11.0-beta1 |
| 0.0.1-techpreview2 | 0.11.0 |
| 0.0.2 | 0.11.2 |
| 0.1.0 | 0.12.0 |
| nightly | 0.12.0 |
Documentation is available on the Nomad project website.
The Vagrant based demo provides a guided example of running and autoscaling an application based on Prometheus metrics using the Nomad Autoscaler.
The remote provider based demo provides guided examples of running horizontal application and cluster scaling.
The Nomad Autoscaler can be easily built for local testing or development using the make build
command. This will output the compiled binary to ./bin/nomad-autoscaler.
As a tech preview, this project is under constant updates, so every day the
nightly release is updated
with binaries built off the latest code in the master branch. This should make it easier for you
to try new features and bug fixes.