Object Storage Service:Slow access to Alibaba Cloud CDN accelerated OSS resources

Description

You want to use Alibaba Cloud CDN to accelerate Object Storage Service (OSS) resources and accelerate access to static resources. However, after acceleration is configured, access to OSS resources by using accelerated domain names is slow.

Cause

If Alibaba Cloud CDN does not cache OSS resources or the configured cache expiration time is short when Alibaba Cloud CDN accelerates OSS, the hit rate is relatively low. The access to OSS resources by using accelerated domain names is slower compared with direct access to OSS.

Solution

1. Log on to the Alibaba Cloud CDN console.

2. In the left-side navigation pane, choose Content Delivery > Domain Names.

3. On the Domain Names page, find the domain name that you want to manage and click Manage.

4. In the left-side navigation tree of the page that appears, click Cache and check whether a cache expiration time is configured.

   • If a cache expiration time is not configured, configure a cache expiration time to prevent Alibaba Cloud CDN point of presence (POP) from removing resources stored on the POP. For more information, see Add a cache rule.

   • If a cache expiration time is configured, check whether the cache expiration time is properly configured. If the cache expiration time is short, we recommend that you extend the cache expiration time.

5. Prefetch hot files, video files, or large files. When you prefetch file URLs, resources are prefetched to Alibaba Cloud CDN acceleration POP in advance to prefetch files from origin servers to Alibaba Cloud CDN and shorten access links. For more information about how to prefetch resources, see Refresh and prefetch resources.

   Note

   After a prefetch task is submitted and complete, POPs immediately start to retrieve resources from the origin server. Therefore, a large number of prefetch tasks cause a large number of concurrent download tasks. This increases the number of requests that are redirected to the origin server. The back-to-origin routing process consumes more bandwidth resources and the origin server may be overwhelmed.

6. If the problem persists, analyze Alibaba Cloud offline logs or real-time logs to identify and resolve the problem.

   • For more information about how to download offline logs, see Download logs.

   • For more information about real-time logs, see Overview.

References

What do I do if the speed is slow when I upload objects to or download objects from OSS?

Applicable scope

• OSS

• Alibaba Cloud CDN