Jujucharms "auto-scaling & auto-healing"


#1

The purpose of this discussion is to discuss Auto-scaling & Auto-healing provided by juju.
If anyone knows about this topic kindly share your knowledge here.


#2

Juju doesn’t currently do any auto scaling or healing. There is a new (in 2.5) Juju on K8s that leverages the underlying K8s scheduler to handle that for those types of workloads.

We’ve found that the rules around scaling/healing can be near impossible to always get right and some issues, like networking/etc, aren’t anything Juju can help by bringing up more units automatically or the like.

There was some work for an autoscale charm that the community was working on:

What are your needs? What are you thinking about. We’re always eager to hear about use cases we need to take a closer look at?


#3

@rick_h
sir i tried charmscaler but it doesn’t work with LXD.
i also tried it deploying through commands given on charmscaler description.
it would be great if you can explain how it can be used with other charms like wordpress.


#4

Hmm, that charm is community drive and I’ve not used it. I’ll have to look into it.

As far as the “how this would/could work” the idea is that Juju provides all the state details and the tools to react based on conditions but that logic in between needs to be handled.

Using tools like the python library for Juju you can monitor things, add additional scripts to write up into nagios/telegraf/prometheus and react based on what you note going on in the system.

You’d need to then script the actions that occur using the same Juju library to scale, remove misbehaving units, execute charm actions. Whatever the needed reaction is.

Does that make sense?