Ad Click Aggregation — Notes
Functional
- Real-time counts: impressions, clicks, conversions per ad/campaign.
- Budget pacing & shut-off.
- Fraud / IVT filtering.
- Reporting dashboards + billing.
Non-functional
- Real-time aggregates < 5 s lag.
- Daily reconciled exact totals.
- 99.9% event durability.
Capacity
- Trillions of events/yr at top platforms.
- HLL keeps cardinality cheap; CMS keeps hot keys cheap.
Trade-offs
- Streaming approximate vs batch exact: combine in lambda/kappa.
- At-least-once + dedup at sink is simpler than exactly-once everywhere.
- Storage: column store for OLAP; KV for per-ad fast lookups.
Refs
- Google Ad Manager engineering posts.
- Facebook "Realtime data processing" blogs (Scribe, Puma).
- Druid / Pinot for ad analytics.