Tuesday, April 10, 2012

Some SQL Server Partitioning and Write Scaling Thoughts...

Brent Ozar PLF - SQL Server - Hash Partitioning, SQL Server, and Scaling Writes

At first glance, SQL Server’s partitioning seems like it should be an easy way to solve problems inserting data into busy tables. If the writes are spread across many partitions it only makes sense that we can avoid write hot spots in SQL Server, right? The truth is much more complicated than it appears.

Asking the Right Questions

Write Throughput & Multi-Tenancy

Write Throughput & Single Tenancy

Writing Faster Without A Database

The Answer

There’s no correct answer. Pushing writes into a partitioned table means having to deal with the pain points of SQL Server’s table partitioning. Splitting writes out among multiple databases or servers can make it difficult to query your data. Implementing caches and queues adds operational complexity and requires expertise that some teams may not have.

The more flexibility you require, the more difficult it becomes to handle additional writes. At some point it might even become necessary to find ways to move the write heavy portions of your application out of SQL Server and into another application that does a better job of handling distributed writes.

Always ask yourself what problem you’re trying to solve and make sure that you’re solving it in the best way. Bolting something like consistent hashing on top of SQL Server is going to be painful, at best. But there may be a different way to solve the problem that’s less painful, operationally simpler, or a little bit of both."


I've been thinking about scaling SQL Server for a while now, from partitioning to sharding and more, and thought this post interesting and one I wanted to capture for future reference (and sharing).

No comments: