Do I need multiple builders?


I have a couple services I deploy to simultaneously sometimes. I often get the error message “builder not available”. Do I need multiple builders? Perhaps I can increase the timeout with --remote-only?

Let me know!


Hi @franzwarning

No you don’t need multiple builders when deploying your app on fly, a single builder can handle multiple concurrent builds.

I don’t know the specifics of what you are trying to deploy but if you have multiple services it might be helpful to have them running as multiple processes in a fly app, this can be configured in a fly.toml as mentioned below

Retrying the deploy with --remote-only? won’t make a difference because the remote builder is the default build

However you could try running a deploy with --local-only instead

Weird. I get this error randomly:

Error failed to fetch an image or build from source: error connecting to docker: remote builder app unavailable
WARN Remote builder did not start in time. Check remote builder logs with `flyctl logs -a fly-builder-shy-pine-3066

I’m deploying three services simultaneously via a github action. All with --remote-only. In some cases two of the builds pass, and one fails. Sometimes all three pass, it’s super random and I can’t figure out a pattern. Quite frustrating :frowning:

From what you’ve described it is likely that your builder has a bug can you try destroying the builder fly apps destroy fly-builder-shy-pine-3066 and retrying the deploy.