--- title: "Troubleshoot caching and content issues" slug: "globalcdn-troubleshoot-caching" updated: 2026-09-17T09:17:45Z published: 2026-09-17T09:17:45Z canonical: "guide.ncloud-docs.com/globalcdn-troubleshoot-caching" stale: true --- > ## Documentation Index > Fetch the complete documentation index at: https://guide.ncloud-docs.com/llms.txt > Use this file to discover all available pages before exploring further. # Troubleshoot caching and content issues Available in Classic and VPC You might run into the following problems when using Global CDN. Find out causes and possible solutions. ## Troubleshoot previous image-displayed issues even after image changes I've changed the image, but the previous image continues to be displayed. #### Cause If the image cached in the Global CDN server is not renewed to the changed image, the previous image may continue to be displayed. #### Solution To delete the content remaining in the cache and renew to the latest content immediately, follow these steps: 1. From the NAVER Cloud Platform console, navigate to **Menu** > **All Services** > **Content Delivery** > **Global CDN**. 2. Click **Purge**. 3. If the same issue occurs even after you perform a purge, delete temporary Internet files on web browsers. - To use web cache services effectively, it is recommended to change the name of the edited content before uploading it. ## Troubleshoot content caching unavailable issues The content is not cached. #### Cause The response header of the common origin server is as follows: ``` HTTP/1.1 200 OK Content-Length : 61246311 Content-Type : video/mp4 Last-Modified : Thu, 20 Apr 2017 08:43:38 GMT ETag : "f4240-5160656c3c3d2" Accept-Ranges: bytes Server: Apache Date : Tue, 15 Dec 2015 02:50:23 GMT ``` You need `Content-Length` and `Last-Modified` in the Global CDN server. If you don't have either of them, the Global CDN server cannot provide efficient caching, which the requests to the origin server may increase. Despite the content that can be cached, if the origin server response has the `Set-Cookie` header, or the Cache-Control header has settings such as `private, no-cache, max-age=0`, the content is not cached. #### Solution - Check whether both `Content-Length` and `Last-Modified` are set. - Check whether the origin server response has the `Set-Cookie` header, or whether the Cache-Control header has `private, no-cache, max-age=0` settings. ## Troubleshoot continued request issues after applying Global CDN I've already applied Global CDN, but the origin server receives continued requests. #### Cause and solution In the early phase of applying Global CDN, there is not much content that is cached on Global CDN servers, so a large amount of requests may be temporarily flowing into the origin server. As time goes by, the cached content increases, so requests to the origin server gradually decrease. ## Troubleshoot continued request issues to the origin server although the set Cache Expiry time has not passed Although the set time on Cache Expiry has not passed, continued requests flow into the origin server. #### Cause and solution Global CDN receives requests from cache servers distributed worldwide. So, if you provide the service to various areas, the request volume to the origin server may increase. Also, if Cache Hit is low, caching is excluded from the cache server before the cache expiry expires, so requests to the origin server may flow in continuously. If requests keep flowing in from the same cache server IP to the origin server, contact [Customer Support](https://www.ncloud.com/support/question/service). Note If you're still having trouble finding what you need, click on the feedback icon and send us your thoughts and requests. We'll use your feedback to improve this guide.