CDN, CloudFront Over S3, Millions of Request-Tier 1

  • Resolved poliarc

    (@poliarc)


    4 years ago

    Hello –

    This is a follow-up to a thread that was closed before due to no further replies (https://www.ads-software.com/support/topic/view-what-is-being-put-delete-to-aws-s3/) – I’ve been looking for answers for a few days now without any luck, so I’m hoping there might be more insight. We have the exact same issue after implementing CloudFront Over S3 CDN with W3: It works well, but on only 2 fairly low traffic LearnDash sites we’re averaging 200k Request-Tier1 requests per day resulting in S3 costs being about 300% above when we just pulled directly from the S3 bucket directly with a simple offload plugin (not even including CloudFront cost, which are negligible; that’s just specifically S3 PUT, COPY, LIST requests).

    Pretty much all file options are checked: wp-includes, attachments, theme files, & custom files. Minify turned on. Object and Database cache off, page and browser cache on.

    On CDN settings I’ve turned off “Export changed files automatically” thinking that maybe it was all LIST requests causing the spike (no new content has been uploaded; literally, zero once we noticed the spike so we could test; we also let the plugins go un-updated), and have checked the option to only manually purge the CDN, but neither of those appear to have decreased the request-tier1 count at all.

    Of note, (maybe, I’m ignorant on most of this) is related to a couple past posts I saw about the max-age / cache headers not being passed. We’ve added a policy on the S3 bucket itself in hopes of that then being passed to CloudFront as per some other suggestions, but headers still aren’t being send with any files on the CDN, so curious if somehow that might be contributing to the problem (we have one other site on a straight origin-pull from the site and its headers are fine; they only get lost w/ origin push to S3->CloudFront setup)

    Any insight and suggestions are much appreciated.

    thanks!

    The page I need help with: [log in to see the link]

Viewing 4 replies - 1 through 4 (of 4 total)
  • Plugin Contributor Marko Vasiljevic

    (@vmarko)

    Hello @poliarc

    I am sorry about the issue you are experiencing and I am happy to assist you with this.
    Just to confirm, you are using the W3 Total Cache CDN feature to offload assets?
    YOu also mentioned a simple offload plugin Can you please confirm if you are using that as well along with the W3 Total Cache?
    Thanks!

    Thread Starter poliarc

    (@poliarc)

    Hi Marko –

    Correct: W3 Total Cache w/ CDN active using “Amazon CloudFront Over S3”. We are no longer using any other offload plugin. I just mentioned that as reference / comparison base for the big increase in S3 cost due to millions of Request-Tier1 requests from S3 once we did activate the CDN option in W3 total cache. Sites that get very little traffic are getting 250,000+ S3 requests per day from the W3 Total Cache plugin when nothing is being uploaded or changed on the website.

    Since that Request-Tier1 type includes LIST (as well as PUT, COPY, & POST), we thought we had narrowed it down to being a result of the “Export changed files automatically” option making thousands of LIST requests a day to compare files and/or the issue that seems to remain that max-age and expiration headers aren’t being passed when the CDN is set to “Amazon CloudFront Over S3”, but shutting that option off didn’t solve it, unfortunately. (even though LIST still “feels” like it’s the cause since we’re definitely not adding any new attachments or files yet getting the huge numbers on S3)

    It’s the same issue as the other post I referenced in the first post that was closed due to no new replies and hoping there’s been a solution / recommendation since then (other than deactivating the CDN option).

    Thanks for your time. Much appreciated.

    Plugin Contributor Marko Vasiljevic

    (@vmarko)

    Hello @poliarc

    Thank you for the information. We are aware of the huge billing that is caused by the AWS invalidations and that’s why the option “Only Purge CDN manually” is there for.
    Cloudflare doesn’t charge for “request”, but for invalidation path.
    https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/Invalidation.html#PayingForInvalidation
    The first 1,000 invalidation paths that you submit per month are free; you pay for each invalidation path over 1,000 in a month. An invalidation path can be for a single file (such as /images/logo.jpg) or for multiple files (such as /images/*). A path that includes the * wildcard counts as one path even if it causes CloudFront to invalidate thousands of files.
    And yes you should also keep the option Export changed files automatically disabled.
    As for the max-age and expiration headers please check this article on how to configure CloudFront to forward the Host header to the origin.
    Thanks!

    Thread Starter poliarc

    (@poliarc)

    OK, thanks for helping narrow down the cause – though I’m not convinced its an invalidation problem because we haven’t uploaded any new attachments, nor updated any plugins, nor manually purged the CDN, and as mentioned the charges are S3 request-tier1, which is PUT, COPY, POST, and LIST requests to the S3 bucket not invalidations on CloudFront – as far as I understand it… I’m obviously not a guru on such things, things ??

    Appreciate your time & suggestions.

Viewing 4 replies - 1 through 4 (of 4 total)
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