How long to boot?

[nwparker]

Hi there, I couldn't find many details around how long would it take a user to open an IDE session?

I tried the cloud demo but it was quite slow, but I understand that this might not be an accurate reflection. So I want to just directly ask what the expectations are for start times (for users without sessions and users restoring sessions).

Thanks!

[jfaltermeier]

Hi,

Theia Cloud itself does not add much on top of a regular Docker container/Kubernetes Pod when it comes to loading times. Mainly, it adds a sidecar container for authentication, but that's it.

If a session for a user is already running and the user comes back to it, there should be no delay, the user will just be forwarded to the running application.

For new sessions the startup time is essentially how long it takes to launch a new Pod with your application on Kubernetes. This depends on several factors:

• How long your application image itself takes to start
• Whether the image is already available on the Kubernetes node or needs to be pulled
  • Theia Cloud can help here with its preloading functionality:
    https://github.com/eclipse-theia/theia-cloud-helm/blob/92ba5b6a23fcea03e6437ed4e6af97cab5ac73b2/charts/theia-cloud/README.md?plain=1#L100
  • You can specify a list of images that will be preloaded on all nodes, avoiding download delays
• If you use persistent storage, Kubernetes might need to provision a new persistent volume/claim. The time for this depends on your cluster’s storage setup.

Finally, Theia Cloud also offers an (experimental) eager mode:
https://github.com/eclipse-theia/theia-cloud-helm/blob/92ba5b6a23fcea03e6437ed4e6af97cab5ac73b2/charts/theia-cloud/README.md?plain=1#L83

In this mode, Theia Cloud keeps running instances available, and users are assigned an already running Pod, which should result in almost no loading time.
The downside is that Kubernetes restarts Pods when persistent storage is attached, so the eager mode currently only works without persistent storage.
Also as mentioned this is more of an experimental feature atm, so there might be bugs.

I hope this clarifies things a bit.

[nwparker]

Amazing! That make sense. Thanks for the detailed answer. I think my only follow-up question is if you do have ballpark numbers of what you guys see in active deployments (I understand it can vary given the above details -- especially given how configurable Theia is).