Cache-related

  • Article

What factors affect the cache hit rate?

What factors affect the cache hit rate?

  • Settings for cache configuration and content prefetching.

  • The HTTP header causes inability to cache.

  • Just added, not many cached files.

  • The type of source station means that the amount of content that can be cached is small.

  • Website visit numbers are low and the expiration time is short, so the number of files hit is small.

What are the default cache rules for Azure Content Delivery Network?

  • The system's default cache rules for web acceleration are:

    1. Dynamic files, such as those with the extensions PHP, ASPX, ASP, JSP, DO, DWR, CGI, FCGI, ACTION, ASHX, AXD, and JSON—are not cached.
    2. Files with the extensions SHTML, HTML, HTM, and JS are cached for half a day (720 minutes) by default.
    3. All other static files are cached for one day (1,440 minutes) by default.

  • The system's default cache rules for download acceleration are:

    1. Dynamic files, such as those with the extensions PHP, ASPX, ASP, JSP, and DO—are not cached.
    2. Files with the extensions 7Z, APK, WDF, CAB, DHP, EXE, FLV, GZ, IPA, ISO, MPK, MPQ, PBCV, PXL, QNP, R00, RAR, XY, XY2, ZIP, and CAB are cached for one month.

  • The system's default cache rules for VoD acceleration are:

    1. Dynamic files, such as those with the extensions PHP, ASPX, ASP, JSP, and DO—are not cached.
    2. MP3 and WMA files are cached for one day.
    3. Audio files such as .mp3 and .wma files—are cached for one day.
    4. Files with the extensions 7Z, APK, WDF, CAB, DHP, EXE, FLV, GZ, IPA, ISO, MPK, MPQ, PBCV, PXL, QNP, R00, RAR, XY, XY2, ZIP, and CAB are cached for one month.

  • The system's default cache rules for live streaming media acceleration are:

    1. TS files are cached for two minutes.
    2. M3U8 files are cached for two seconds. 

Cache rule logic:

  1. If you configure no-cache rules, then matches are assigned in order of priority. However, because matching also requires cache rules, the cache rules are matched from high to low.

  2. If a particular URL is not matched in either the cache or no-cache rules, the Content Delivery Network's default rules will be followed.

What is the maximum duration for file caching at a Content Delivery Network node?

The maximum duration for file caching at a Content Delivery Network node is set according to your cache rules, and the system sets no limit for the duration.

How long does it take to synchronize the cache rules and to synchronize the cache files at a Content Delivery Network node?

After you set your cache rules, it takes about 10 min to issue them. The synchronization time for the cache rules at a Content Delivery Network node depends on the set cache rules and the file size.

Can cache rules be configured for wildcard domain names?

Can cache rules be configured for wildcard domain names? If you have created a wildcard domain name, the cache rules will be set up under the wildcard domain name. To help simplify the process, wildcard domain names are mainly used for multiple domain names with the same configuration. They can be created at the same time as real domain names, with the configuration for the real domain name taking priority for matching. For example, if the rule for a1.example.com is different, you can create a new endpoint for a1.example.com and create cache rules there. In this situation, the configuration there would have priority over the configuration for *.example.com.