2个SQL服务器，但不同的tempdb IO模式（在1时峰值）上下波动5MB /秒-0.2MB /秒

Question

I have 2 MSSQL servers (lets call then SQL1 and SQL2) running a total of 1866 databases

• SQL1 has 993 databases (993203 registered users)
• SQL2 have 873 databases (931259 registered users) Each SQL server has a copy of a InternalMaster database (for some shared table data) and then multiple customers, 1 database per customer (Customer/client not registered user).

At the time of writing this we had just over 10,000 users online using our software.

SQL2 behaves as expected and Database I/O is generally 0.2MB/sec and goes up and down in a normal flow, IO's goes up on certain reports and queries and so on in a random fashion.

However SQL1 has a constant pattern almost like a life support machine.

I don't understand why both servers which have the same infrastructure, work so differently? The spike starts at around 2MB/sec and then increases to a max of around 6MB/sec. Both servers have identical IOPS provisions of data, log and transaction partitions and identical AWS specs. The Data file I/O shows that tempdb is the culprit of this spike.

Any advice would be great as I just can't get my head around how 1 tempdb would act different to another when running the same software and setup on both servers.

Regards

Liam

Answer 1

Liam,

Please see this website that explains how to configure TEMPDB. By looking at the image, you only have one file for the TEMPDB database.

http://www.brentozar.com/sql/tempdb-performance-and-configuration/

Hope this helps