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0 pointscldellow4y ago0 comments

Yeah, it's for get embed code.

Could definitely have used Dynamo as a persistent layer, but the PNGs are transient - the definition is stored in a GitHub gist owned by the user (another free tier! :). But generating the PNGs is expensive, so they get cached in S3. An S3 lifecycle rule automatically prunes PNGs older than a month, and they'll get regenerated from the gist if needed.

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2 comments · 1 top-level

orf4y ago· 1 in thread

A month seems like a long time, I’d have assumed you could probably delete 95% of the images within 3 days. Out of interest is the month long expire rule a guesstimate or something based on actual numbers?

cldellowOP4y ago

It's just a number, I haven't looked at any request logs to see what hit rates are like.

From a money perspective, expiring them never would be fine, and a good trade off to get better latency on subsequent loads. However, if the underlying gist is deleted, I'd like the PNG to eventually go away.

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