CDN Cache Utilization
- CDN Cache Hits – Number of requests to your CDN service served directly from the CDN cache.
- Hits – Number of requests to your CDN service requiring pull from your origin server.
- Cache Hit Ratio – Ratio CDN Cache Hits / (CDN Cache Hits + Origin Hits)
HTTP Status Codes
- Number of 2xx status codes – Those status codes mean that the requests were successfully completed.
- Number of 3xx status codes – Let’s look at few examples.
- 304 (Not Modified) – Means that your CDN content expired but your origin content is the same as in the CDN cache. In those cases we continue to cache your CDN content. In another words – everything is fine with those status codes.
- 301 (Moved Permanently) – Means that the request was redirected to a different URL (in most cases to your origin). You should avoid redirecting to your origin because in those cases you are not using CDN. Usually the problem is caused by a permanent redirect on your origin server redirecting non www requests to www requests.
- Number of 4xx status codes – Let’s look at few examples.
- 403 (Forbidden) – Those status codes are generated when the requests are blocked by URL Signing, Password Protection, Country Access Policy, Hotlinking Policy, IP Access Policy or Block Crawlers.
- 404 (Not Found) – Means that content was missing on your origin server.
- 499 – Those status codes are generated when the client closes his connection before the edge server completes the request.
- Number of 5xx status codes – Those status codes are generated when there is a problem in communication between your origin server and the edge server. To minimize number of 5xx status codes we recommend to use CDN Static Push instead of CDN Static as our storage servers have premium connection to our edge servers.
- 2xx Ratio – Ratio 2xx / (2xx + 3xx + 4xx + 5xx)
Sincerely your CDNsun team.