Case Study: Bing Ads achieves nearly unlimited scale and zero‑downtime migration with Microsoft Azure (Azure SQL Database)

Bing Ads Extreme Scale using Azure SQL Database

Microsoft’s Bing Ads faced an extreme-scale challenge: supporting millions of advertisers, hundreds of millions of campaigns and tens of billions of keywords and ads while maintaining real-time responsiveness and zero downtime. On-premises scale-up approaches and hardware costs were no longer practical as data volumes grew into the hundreds of terabytes and query load demands threatened service performance and growth.

Bing Ads fully migrated and re-architected its data tier onto Azure SQL Database, using transactional replication and multi-cast seeding for zero-downtime cutover, custom sharding with a shard map manager and middle-tier fan-out, Elastic Database jobs for maintenance, clustered Columnstore indexes for BI, and geo-replication for HA. The move delivered virtually unlimited scale (campaigns ~150 TB across 190 DBs; BI ~300 TB across 368 DBs), dramatically faster queries (BI tail latency improved from >10s to ~2s), increased keyword query capacity (50k → 8M), reduced operational overhead and eliminated costly on-premises infrastructure.

Bing Ads