Support » Plugin: W3 Total Cache » Amazon Cloudfront Invalidations

  • I have this plugin running on two sites that use Amazon Cloudfront for the CDN. On May 3, one site started sending invalidations to Cloudfront. At first there were anywhere from a few to 1000 invalidations per day. Starting May 19, there were 7000 invalidations per day. Amazon charges $0.005 per invalidation after 1000, so I ended up with a $500 bill for Cloudfront for May.
    I have disabled the CDN for now, so it stopped. As far as I can tell, W3 Total Cache was the only plugin updated around that time, and the only one that should affect CDN.
    I saw another post which said to use the generic setting instead of the Cloudfront setting, so I will give that a try. Is there anything else I can do to make sure this doesn’t happen again?


Viewing 12 replies - 1 through 12 (of 12 total)
  • For what it’s worth, here are the plugins that did update on May 3, when the problem started:
    May 3 06:54 w3-total-cache/
    May 3 06:54 flowpaper-lite-pdf-flipbook/
    May 3 06:54 enable-media-replace/
    May 3 06:54 advanced-nocaptcha-recaptcha/

    Plugin Support gidomanders


    It is W3 that generates the invalidation requests, but we’re working on an option to only invalidate on manual purges. So for now the generic mirror works good enough, but in a future release you can use the CloudFront specific CDN option again.

    you guys ruined my AWS bill. I have a massive $100 bill in just 2 days. This is shameful on you guys.

    Plugin Support gidomanders


    We’re very sorry to hear that. We’re working on the solution to be released as soon as possible.

    I have had the same issue with the plugin. This was on a simple WooCommerce site with a few thousand products. Notice it incurred over $6,000 in fees.

    Amazon CloudFront Invalidations $6,485.76
    $0.000 per URL – first 1,000 URLs / month.1,000 URL$0.00
    $0.005 per URL – over 1,000 URLs / month.1,297,151 URL$6,485.76

    We are experiencing the same issue now, it cost us 150$ in about only 1 hour.
    Cost hundreds of $ when W3TC invalidating Cloudfront CDN records.

    Is there a option to purge CDN manually instead of let it done by w3tc automatically?

    Plugin Support gidomanders


    @hileon I’m very sorry that we’re causing such bills. We’re working on an option to only send invalidation requests when you click the purge button and we’ll add a notification about the possible costs of invalidation requests when that option is not enabled.

    We did a rebuild thumbnail which I had no clue was linked with these invalidations. We had 48 564 invalidations which has so far cost us $237.82. There where numerous similar invalidations over the past few months but not of this magnitude which caused it to pass by unnoticed.

    I see no option anywhere in W3 cache to disable this feature and I originally thought it was only triggered by manual cache purge.

    @gidomanders how is the updated feature of invalidations coming? Is there a way to disable invalidations permanently?

    Plugin Support gidomanders


    @fireflake Unfortunately we’re not able to get the feature to only invalidate on purge ready for the upcoming release. That release will be a minor release, v0.9.7.1. The feature is listed for v0.9.8 though, so you guys have to stay tuned for a bit longer.

    As I suggested before, as a temporary fix, use the generic mirror option for CDN. That way no invalidation requests will be sent.

    @gidomanders Thank you for a quick response and heads up!

    I have changed to generic mirror CDN now and hopefully we will see an effect of this change on our upcoming AWS bill! 🙂

    I never get outraged, but this is crazy.

    You add a feature that can’t be turned off that causes thousands of dollars of charges to users without telling them? I just spent hours figuring out why my bill was so high, and it was due to these invalidations. I’m lucky to have caught it.

    Do you have any idea how unethical this is? The person above said it cost him $6000… that’s insane. I mean literally hundreds of thousands of dollars if not more this is costing people that have no idea. And 4 months to fix this? Not even yet?

    Have you emailed users or notified AWS? You guys have over a million users. I understand people make mistakes and this is a free plugin without warranty, but this needs to addressed publicly so at least people know.

    Plugin Support gidomanders


    @andrewfitz, of course we don’t want anyone to be frustrated. There are a few important things to remember:

    1. There are various other providers that you can use for free or lower cost than AWS until the fix is I also commented as temporary solution to use generic mirror.
    2. The functionality as it works today has been that way for quite some time and the reports from end users of issues is very low, which determines the priority of changes. Changes take time and must be tested.
    3. We have very little data on how our software is used and by whom, so the few people who’ve pointed this issue out are vocal because they’re investing heavily in their sites.
    4. As for making releases more frequent, we’ve been supportive of forks and contributions from the community to address issues that are important to them. The community has not prioritized this fix given the amount of control and alternative options available. AWS has always been among the more expensive providers in the market.
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