After hitting 720 concurrently replicating subscribers at MEDC 2007, we decided to bring the big rack of servers to Tech Ed 2007 in Orlando to see if we could break that record.  Rather than trying to blow through that record right away, we decided to see how far we could push a single IIS server before needing to scale it out with Network Load Balancing.  So we methodically put our 4-Tier Merge Replication architecture through its paces 100 subscribers at a time in order to collect metrics that would be of value to organizations of every size.  Using the 70 MB AdventureWorksDW database that's included with SQL Server 2005, we gathered the following data on Day 1:

100 Subscribers:

  • IIS - CPU: 18% | Memory: 245 MB | Network Utilization: 1% | Disk: 8%
  • SQL Distributor - CPU: 4% | Memory: 4.79 GB | Network Utilization: .65% | Disk: 28%
  • SQL Publisher - CPU: 29% | Memory: 4.6 GB | Network Utilization: .84% | Disk: 4%
  • Client Sync Times - High: 58.7 Sec | Low: 1.7 Sec | Avg: 15.8 Sec

200 Subscribers:

  • IIS - CPU: 18% | Memory: 259 MB | Network Utilization: 1% | Disk: 8%
  • SQL Distributor - CPU: 5% | Memory: 4.83 GB | Network Utilization: .31% | Disk: 30%
  • SQL Publisher - CPU: 32% | Memory: 4.52 GB | Network Utilization: .1% | Disk: 3%
  • Client Sync Times - High: 3.1 Minutes | Low: 1.7 Sec | Avg: 56.05 Sec

300 Subscribers:

  • IIS - CPU: 14% | Memory: 283 MB | Network Utilization: 1% | Disk: 12%
  • SQL Distributor - CPU: 4% | Memory: 4.82 GB | Network Utilization: .45% | Disk: 48%
  • SQL Publisher - CPU: 29% | Memory: 4.65 GB | Network Utilization: 1% | Disk: 4%
  • Client Sync Times - High: 8.4 Minutes | Low: 1.7 Sec | Avg: 2.1 Minutes

 In order to describe the 4-Tier architecture to attendees, Darren Flatt used his precision drawing skills to reproduce a Visio diagram on our white board:

 SQL Server Compact Edition guru and MVP Ginny Caughey was on hand to help run the booth and provide expert answers to attendee questions:

Merge Replication guru Darren Shaffer made an encore return to our booth after MEDC 2007 to help walk attendees through the intricacies of synchronizing devices with SQL Server 2005:

 Steve Hegenderfer brought his unequaled technical prowess to bear to ensure that our booth would be a huge success:

 Brian Lio concentrates deeply while trying to solve a complex problem that only he can figure out:

SQL Server luminary and author of "Hitchhiker's Guide to Visual Studio and SQL Server," Bill Vaughn came by to lend us a hand and show us how it's really done:

Day 1 went very well and we're all looking forward to Day 2 where we'll increase our replication load to up over 500 simultaneous subscribers.

Rob