Cache: Cache restore slow compared to Semaphore CI

[davetapley]

Migrated from here.

Semaphore CI have a cache similar to actions/cache@v1 but theirs only takes six seconds to restore our 760MB node_modules Semaphore CI, compared to twenty eight seconds on GitHub Actions.

This was on Semaphore's lowest machine type which is comparable to the specifications of the GitHub-hosted runners.

This behavior was observed on multiple builds across several days.

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I don't have a repro because this was observed on a private repo, but it's easy enough to replicate. I'll create one if it's deemed necessary?

[dhadka]

Hi @dukedave, are your caches actually being created? There is currently a 400 MB limit on the cache size (we will be increasing this limit very soon). I suspect the restore action is failing as a result and you're having to fetch the dependencies from their source. We also released a perf improvement in mid December that should also help cut download times.

[dhadka]

The cache limit increase is now released. Please try again and let us know if you're still seeing slow restore times.

[smorimoto]

I suspect this is a problem with the compression algorithm used.

[smeijer]

This is also my experience. 35 sec for ~ 161 mb.

[smorimoto]

We're already working on making it faster, and in my environment it's about three times faster. The next major version will definitely improve.

[smorimoto]

See this PR: https://github.com/actions/cache/pull/202

[smorimoto]

Note that this PR will take some time to merge.

[joshmgross]

👋 Cache Version 2 has multiple performance improvements, including using zstdfor compression instead of gzip. See https://github.com/actions/cache#whats-new for more details.

I don't think there's anything that's specifically actionable here, if you have any other performance suggestions please open an issue.

[mbbernstein]

Hi,

I've the same issue here:

Thanks,
Michael

[smorimoto]

Could you try to use the v2?

[mogusbi]

I'm also seeing the problem of the cache restores being very slow. It's ranging anywhere between a few seconds to 12 minutes as well as it just giving up after a period of time

When it goes bad:

When it goes well:

Workflow in question can be found here: https://github.com/motech-development/platform/blob/master/.github/workflows/checks.yml

Actions here: https://github.com/motech-development/platform/actions

[joshmgross]

👋 Hey all, this specific issue has already been resolved. If you are experiencing slow cache restores, please file a new issue with details on your specific use case and expected behavior.