Support » Plugin: W3 Total Cache » W3TC cache settings and unusually high Amazon S3/AWS fees

  • I was wondering if anyone knew which W3TC cache settings might be contributing to my high Amazon S3 / AWS fees?

    In any given month, it looks like I’m getting charged ~$10 for PUT, COPY, POST, or LIST requests (856,287!) and ~$10 for 96G of “data transfer in”… this with only ~800 page loads for the month. The blog is photo heavy (11 MB on the front page).

    I think I may have changed some of the W3TC default cache settings a few months ago, not realizing it would affect my S3/AWS billing. I’m not sure what the original W3TC cache values were.

    Any suggestions on which W3TC cache timing settings I should adjust to lower my costs? I have a feeling my current cache settings are not efficient and are costing me a lot of money (and performance if the files are not being served from the cached cloudfront files!).

Viewing 5 replies - 1 through 5 (of 5 total)
  • Plugin Author Frederick Townes


    Are you using force overwriting option? I suggest switching to origin pull for cloudfront.

    Yes, “force over-writing of existing files” checkbox is ticked when I upload to the CDN, however I haven’t made any changes to the blog/uploaded anything new in the last few months, so I don’t think this could be the cause of the 800 000+ PUT, COPY, POST, or LIST requests on S3 or the 96GB of “data transfer in” reported by AWS.

    How do I go about “switching to origin pull for cloudfront”?

    Plugin Author Frederick Townes


    Simply select that option on the general settings tab and then populate the fields needed in the configuration box on the cdn settings tab.

    Thanks, I found Origin Pull under the CDN dropdown menu in the general settings tab and switched from Origin Push to Origin Pull.

    After switching to Origin Pull I noticed in the CDN tab that the Access key ID: and Secret key: were blank and that the Origin: now displayed my blog’s url instead of the S3 bucket I had before.

    I re-entered my AWS Access Key ID and Secret Key, but is this necessary now that I am using Origin Pull and bypassing the S3 bucket? I also entered my cloudfront distribution domain name under “Replace site’s hostname with:” and populated 7 of the CNAME fields with my cloudfront cnames.

    Now, when I click Test Cloudfront Distribution, I get the following notification: Error: Distribution for origin “www.[myblogurl].com” not found.

    Is this a problem? The images on the blog appear to be loading properly from the CDN (“reading, images2.mycdncname” etc appears in the firefox status window when I empty the browser cache and load the page). Everything seems to be working as it should, but I do get that error code when I click Test Cloudfront Distribution — is this because the plugin is looking for a cloudfront distribution bearing my blog’s domain name?

    Also, I noticed a new W3TC suggestion pop-up when I switched from Origin Push to Origin Pull:

    “Maximize CDN usage by modify attachments url”

    Is this something I should do now that I have switched from Origin Push to Origin Pull? ie enter my blog’s domain name in the Modify attachment URLs “Domain to rename” field and click start?

    Plugin Author Frederick Townes


    W3TC is going to attempt to configure your cloudfront distribution for you. So yes it’s a problem that the distribution you’re attempting to create is throwing errors. If you need further help, please submit a bug submission form from the support tab of the plugin.

Viewing 5 replies - 1 through 5 (of 5 total)
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