97 lines
6.0 KiB
Markdown
97 lines
6.0 KiB
Markdown
**Drop 3 – DIY CDN: Serving shoppers from 50 feet away**
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*Part of the LinkedIn series “Edge Renaissance: putting compute—and the customer—back where they belong.”*
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---
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### ☕ Executive espresso (60‑second read)
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* \*\*Why bother? \*\* Third‑party CDNs still push requests hundreds of miles; your stores already sit *next to the customer.* Turn each three‑node Proxmox cluster into a micro‑PoP and you cut the round‑trip by up to **180 ms**—the difference between “meh” and magic.
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* **Speed sells.** Akamai found a **100 ms** delay dents conversions by **7 %** ([Akamai][1]), while Google / Deloitte showed a 0.1‑second boost lifts retail conversions **8.4 %** and AOV **9.2 %** ([Google Business][2]).
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* **Own the edge, own the margin.** Commercial CDNs bill \~\$0.04‑\$0.05/GB at scale (Akamai calculator, 2025) ([BlazingCDN Blog][3]) and even small‑plan Cloudflare traffic costs **\$1/GB** after miniscule free tiers ([Cloudflare][4]). In‑store delivery rides bandwidth you’re *already* paying for.
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> **Bottom line:** a private, location‑aware CDN isn’t a science project—it’s “back to basics” Internet architecture that converts better and costs less.
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---
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## 1 Why roll your own instead of renting a PoP?
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| Question senior execs ask | Third‑party CDN answer | Retail‑edge answer |
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| ------------------------- | ------------------------------------------ | ------------------------------------------- |
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| *How fast can we get?* | 40‑200 ms (public PoP → origin) | **< 30 ms TTFB**—cluster is in the building |
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| *Who keeps the data?* | TLS keys & logs sit off‑prem | Everything stays in your closet |
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| *What’s the true cost?* | Pay per GB forever + egress back to origin | One‑time cap‑ex; incremental \$0 |
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---
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## 2 Anatomy of a **Retail Edge Delivery Network (REDN)**
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```
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[ Shopper’s phone ] ←Wi‑Fi / LTE→ [ Store closet ]
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├── Varnish / Nginx (static cache)
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├── WASM / Lua FX (per‑request logic)
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├── KVM / LXC (POS, inventory API)
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└── Ceph pool (replicated assets)
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↑ nightly diff
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[ S3 DR bucket ] ← WireGuard mesh →
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```
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*One shoebox‑sized cluster wears two hats:* it runs operational apps **and** serves front‑end assets + edge functions. No extra licences, no extra racks.
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---
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## 3 What “50 feet away” feels like to the customer
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| Scenario | Traditional path | REDN path | Result |
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| ------------------------------- | ---------------------------------------- | ----------------------------------- | ----------------------------- |
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| Product image on PDP | Phone → CDN PoP (300 mi) → Origin → Back | Phone → In‑store cache | Image paints **5‑10× faster** |
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| “Pick up in 30 min?” badge | PDP JS → Cloud API → ERP | PDP JS → `/inventory` API on closet | Real‑time stock, no spinner |
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| Vision‑AI loss prevention alert | Camera stream to cloud | GPU container on cluster | Sub‑50 ms alert, zero egress |
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---
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## 4 Cost lens (after you bank the CX upside)
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| Variable cost on 100 TB/mo | Commercial CDN | REDN |
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| -------------------------- | ----------------------------------------------------- | --------------------------- |
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| Transfer fees | 100 TB × \$0.045 = **\$4.5 k** ([BlazingCDN Blog][3]) | **\$0** (uses store uplink) |
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| Cloud egress to origin | 10 TB × \$0.09 = **\$900** (typ. AWS) | **\$0–\$50** (delta sync) |
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| TLS key escrow | Enterprise add‑on | **N/A** (you hold keys) |
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*Hardware amortised over 4 yrs = <\$105/mo per store; ROI < 18 months.*
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---
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## 5 Build‑it‑this‑week blueprint
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1. **Add a CDN role** to the existing Proxmox cluster:
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```bash
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pct create 1300 varnish-template --net0 name=eth0,bridge=vmbr0,ip=dhcp
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```
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2. **Pin assets** on the Ceph pool (`/ceph/cdn`).
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3. **Deploy edge function** (promo injector) via containerised WASM runtime.
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4. **Publish GeoDNS**—`cdn.example.com` resolves to store IP ranges, with a fallback to an S3‑backed origin.
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5. **Wire nightly sync**: Proxmox Backup Server δ‑snapshots to a central bucket for DR.
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---
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## 6 Customer‑obsessed use‑cases to steal today
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* **Hyper‑local promos**: Edge function reads loyalty cookie + on‑hand stock, swaps hero banner only if the item is actually in aisle 7.
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* **AR try‑on textures**: 4K assets live in the closet; shoppers on store Wi‑Fi stream instantly.
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* **Real‑time order status**: BOPIS app hits a μ‑service next to the pick‑pack robots, not a far‑off DC.
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* **Zero‑downtime kiosks**: Even if the ISP blips, cached JS + local APIs keep self‑checkout humming.
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---
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### Coming up next ➡️ *“Edge Workloads That Win Hearts (and Wallets).”*
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We’ll dive into the AI vision, robotics, and inventory apps that turn this infrastructure into a true competitive moat.
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*Stay subscribed—your customers, and your CFO, will thank you.*
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[1]: https://www.akamai.com/newsroom/press-release/akamai-releases-spring-2017-state-of-online-retail-performance-report?utm_source=chatgpt.com "Akamai Online Retail Performance Report: Milliseconds Are Critical"
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[2]: https://www.thinkwithgoogle.com/_qs/documents/9757/Milliseconds_Make_Millions_report_hQYAbZJ.pdf?utm_source=chatgpt.com "[PDF] Milliseconds Make Millions - Think with Google"
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[3]: https://blog.blazingcdn.com/en-us/akamai-cdn-cost-calculator-2025 "Akamai Content Delivery Network CDN Cost Calculator for 2025"
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[4]: https://www.cloudflare.com/plans/?utm_source=chatgpt.com "Our Plans | Pricing - Cloudflare"
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