Orange Book
CDN and web performance

12 · Tiered Cache, Cache Reserve, and origin shielding

Consolidate multi-region misses with Smart Tiered Cache, then decide whether object lifetime and economics justify a persistent Cache Reserve layer.

Edited and verified by Orange Book Editorial Team ·

CDN · PHASE 4ADVANCEDAbout 30 minutesSmart Tiered · Reserve · origin shield

The layers solve different problems

Tiered Cache makes lower-tier locations consolidate misses through fewer upper-tier locations, reducing origin connections. Cache Reserve adds a paid, persistent storage layer for long-lived public objects with expensive origin egress. Neither makes an otherwise private response safe to cache.

Multi-level cache architecture with visitor, lower tier, upper tier, Cache Reserve, and origin
A lower-tier miss checks an upper tier. When enabled and eligible, the upper tier can consult Cache Reserve. The origin is reached only when no cache layer has a usable object.Open original
Detailed description
A visitor reaches a nearby lower-tier Cloudflare data center. On a miss, the lower tier contacts the upper tier selected by Smart Tiered Cache. If Cache Reserve is enabled and the object is eligible, the upper tier can read persistent cache before contacting the origin. The response fills the layers on its return path.
  1. 01
    Visitor and lower tier

    Serve popular objects nearby without sending every regional miss directly to the origin.

  2. 02
    Smart upper tier

    Consolidates lower-tier misses to improve global reuse and reduce origin connections.

  3. 03
    Cache Reserve

    Paid persistence; an object needs at least a ten-hour freshness TTL and Content-Length.

  4. 04
    Origin

    Provides content only when the preceding layers miss or require revalidation.

Choose Tiered Cache before Reserve

CapabilityCurrent planGood fitCost boundary
Tiered Cache + Smart TopologyFree / Pro / Business / EnterpriseMulti-region visitors, one or a few originsCurrently no extra product fee
Public-cloud Region HintAll plans; AWS/GCP/Azure/OracleAnycast or regional-cloud origin whose location is ambiguousCurrently no extra product fee
Regional / Custom TopologyEnterpriseComplex global origins and bespoke topologyContact account team
Cache ReservePaid plan requiredLong-lived public large objects and expensive origin egressUsage-based storage and operations

For most projects, enable Smart Tiered Cache and measure origin-request reduction before modeling Reserve from real bandwidth costs. Do not turn on every layer at once and guess the benefit.

Enable Smart Tiered Cache

Establish a baseline

Record origin requests, egress bytes, cache-hit ratio, main object sizes, region distribution, and release frequency. Separate identity APIs and uncacheable traffic so a blended hit ratio does not mislead.

Enable Smart Topology

Under Caching → Tiered Cache, enable Tiered Cache and select Smart upper-tier topology. Tiered Cache and Smart Topology are currently available on every plan.

Set a Region Hint for a public-cloud origin

Under Caching → Tiered Cache → Origin Configuration, find the origin IP or Hostname and select its actual cloud provider and region. Do not infer origin location from visitor geography. A Region Hint describes where the origin runs in AWS, GCP, Azure, or Oracle Cloud.

Observe more than one hit

Compare origin requests, egress, and upper-tier fills before and after. When your request logs expose the field, CacheTieredFill helps confirm that Tiered Cache participated.

Cache Reserve eligibility and economics

An object needs standard cache eligibility, a freshness TTL of at least ten hours, and Content-Length before Reserve can admit it. Default retention starts at 30 days and resets on access. Retention determines whether the object stays in persistent storage; freshness TTL still determines when Cloudflare revalidates with the origin.

As of this page's verification date, public rates are:

ItemPrice
Storage$0.015 / GB-month
Class A writes$4.50 / million operations
Class B reads$0.36 / million operations

Operation quantities round up to the next million, and rates can change. Recheck official pricing before enabling. Rewriting many short-lived small files can cost more in operations than it saves in origin egress. Repeatedly read, long-lived large objects are closer to the intended fit.

Reserve decision table

ObjectRecommendationReason
Versioned software download or public datasetModel and testLong-lived, repeatedly read, potentially expensive origin egress
Public originals and long-lived mediaPilotOriginals can qualify; test Range behavior and file limits
Dynamic HTML or frequently updated APIUsually unsuitableDifficult ten-hour TTL and frequent writes/revalidation
Private user PDF/image resultDo not use shared ReserveAuthorization and revocation take priority
Request to an R2 public bucket on a zone domainDoes not use Cache ReserveExplicitly excluded by current behavior

Validate media and invalidation semantics separately

Cache Reserve currently does not support origin Range requests from Reserve, and transformed image variants are ineligible. URL purge immediately affects edge and Reserve. Tag, Host, Prefix, and Purge Everything make Reserve revalidate on the next request, while storage charges continue until retention expiry or deletion.

Acceptance and rollback

  • Origin requests and connections fall after Smart Tiered is enabled without degrading 5xx, TTFB, or release freshness.
  • A public-cloud Region Hint matches the actual origin region and updates as part of origin migration.
  • Reserve receives only inventoried objects that satisfy TTL, Content-Length, cacheability, and public visibility.
  • Cache Reserve Analytics shows storage, Class A/B operations, requests, and egress savings before expansion.
  • Pausing Reserve does not delete stored data. Full deletion requires disabling it and using Delete Storage; Cloudflare notes that deletion can take up to 24 hours.

The final phase combines non-cache content optimization, dynamic routing, and end-to-end measurement into one diagnostic loop.

Primary sources

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