Performance Metrics

CDN provides stable acceleration and relieves pressure on origin servers. You can view performance metrics before and after CDN is used to check the acceleration effect.

Common Metrics

The following table lists CDN common metrics.

Metric	Description
Latency	Total time required for uploading or downloading a file.
Packet loss rate	Ratio of the number of lost packets to the number of sent packets.
Origin pull ratio	This ratio includes the origin request ratio and pull traffic ratio. Origin request ratio = Requests with cache misses/All requests on CDN PoPs. A cache miss occurs when the content is not cached, the cache of the content (cacheable) has expired, or the content cannot be cached. Pull traffic ratio: Origin traffic is generated when CDN PoPs request content from origin servers. Pull traffic ratio = Pull traffic/(Pull traffic + Traffic generated by user requests). A lower ratio indicates a better performance.
Cache hit ratio	Cache hit ratio includes request hit ratio and traffic hit ratio. A higher cache hit ratio indicates a better performance. Cache hit ratio = Number of requests that hit caches/Number of total requests Traffic hit ratio = Traffic generated when CDN PoP caches are hit/Total request traffic Total request traffic = Traffic generated when CDN PoP caches are hit + Traffic generated during origin pull NOTE: The traffic hit ratio indicates the load on the origin server. A lower traffic hit ratio means a larger origin pull traffic, which leads to a larger output traffic and higher bandwidth consumption on the origin server.

When CDN is used, the latency, packet loss rate, and origin pull ratio decrease, whereas the cache hit ratio increases. However, the acceleration performance varies between service scenarios and types, even if the CDN configuration is the same. Therefore, this topic provides only qualitative indicators for your references.
If you do not use CDN, the origin pull ratio is 100% and the cache hit ratio is 0.

Acceleration Case

This test uses the universal test method in the industry. The service provider is Tingyun. Test objects are Huawei Cloud OBS buckets and Huawei Cloud CDN. Test carriers are China Unicom and China Telecom.

Latency
Unit: second
Availability
The availability of OBS buckets and CDN is 100%.

Detailed data

Time	OBS			CDN
Time	Latency (s)	Availability (%)	Monitoring Sites	Latency (s)	Availability (%)	Monitoring Sites
Nov 18 15:12	1.149	100	57	1.227	100	62
Nov 18 16:12	1.075	100	167	0.616	100	169
Nov 18 17:12	0.867	100	172	0.433	100	171
Nov 18 18:12	0.7	100	169	0.321	100	169
Nov 18 19:12	0.94	100	173	0.534	100	173
Nov 18 20:12	1.119	100	176	0.765	100	176
Nov 18 21:12	0.841	100	175	0.609	100	176
Nov 18 22:12	0.983	100	181	0.682	100	180
Nov 18 23:12	0.923	100	173	0.58	100	174
Nov 19 00:12	1.08	100	184	0.737	100	184
Nov 19 01:12	1.147	100	180	0.812	100	178
Nov 19 02:12	1.29	100	181	0.853	100	183
Nov 19 03:12	1.041	100	177	0.617	100	176
Nov 19 04:12	1.339	100	184	0.997	100	184
Nov 19 05:12	1.035	100	179	0.74	100	179
Nov 19 06:12	0.865	100	180	0.566	100	181
Nov 19 07:12	1.258	100	176	1.071	100	175
Nov 19 08:12	1.338	100	170	0.878	100	170
Nov 19 09:12	1.085	100	155	0.705	100	155
Nov 19 10:12	1.213	100	168	0.822	100	169