Edge Security Acceleration (ESA) provides the tiered cache feature, an advanced technology that optimizes cache performance, to cache resources on points of presence (POPs) at different levels globally. This ensures that requests are served from POPs that are close to clients as fast as possible to improve the performance and efficiency of the overall content delivery system.
Overview
ESA has more than 3,200 POPs all over the world. Tiered cache works with smart routing to divide the POPs into two categories: POPs that are closer to clients and POPs that are closer to the origin server. If a client initiates a request for a specific resource, ESA locates the POP that is closest to the client and then checks whether the requested resource is cached on the POP. If the resource is not cached, ESA continues to search for the resource on upper-tier POPs. If the requested resource cannot be found on POPs of all tiers, ESA asks the origin server for content. In most cases, the requested resources can be found on POPs. The tiered cache feature reduces requests to the origin server, which relieves origin loads and optimizes bandwidth utilization. The feature also improves the access speed by allowing clients to access the closest POPs.
How it works
Configuration | Description | Diagram |
Default | Edge POPs are the POPs that are closer to clients. If the requested resource is not cached on the edge POPs or the cache is expired, the POPs request the resource from the origin server. |
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Smart Tiered Cache | POPs of this tier are closer to the origin server. If you turn on Smart Tiered Cache, the system allocates POPs based on the location of the origin server. This helps reduce the number of connections to the origin server, which relieves the loads on the origin server. Smart Tiered Cache is available in all plans. |
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Smart Tiered Cache + Regional Tiered Cache | POPs of this tier sit between edge POPs and POPs closer to the origin and are located at the center of each geographical region. If you turn on Smart Tiered Cache and Regional Tiered Cache, ESA searches for the requested resources on the POPs that are closest to the clients. If no resources are found, ESA continues to search for the requested resources on the regional POPs. If the requested resources still cannot be found, ESA asks the upper tier for content. The Regional Tiered Cache feature provides an additional layer of cache POPs and helps increase the cache hit ratio. Regional Tiered Cache is available only in Enterprise plans. |
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ESA automatically allocates edge POPs to new websites added to ESA. You can turn on Smart Tiered Cache and Regional Tiered Cache based on your business requirements.
Feature availability
Feature | Basic | Standard | Advanced | Enterprise |
Smart Tiered Cache | Yes | Yes | Yes | Yes |
Regional Tiered Cache | No | No | No | Yes |
Procedure
Log on to the ESA console.
In the left-side navigation pane, click Websites.
On the Websites page, find the website that you want to manage, and click the website name or View Details in the Actions column.
In the left-side navigation tree, choose .
In the Tiered Cache section, click Configure.
Turn on the Smart Tiered Cache switch.
If you subscribe to an Enterprise plan, you can also turn on the Regional Tiered Cache switch to increase the cache hit ratio.
Click OK. After you enable the tiered cache feature, the feature requires 3 to 5 minutes to take effect.