Replay

One of the features I was asked to implement for WorkloadTools is the ability to replay commands to a database name different from the one recorded in the source workload. This is something that I had been planning to implement for a while and it totally makes sense. Usually, you have two identical environments for the workload capture and replay, both with the same databases. Sometimes it makes sense to have two different databases as the source and target for the workload, for some particular reasons: resources constraints, ease of testing and so on. [Read More]

In a previous blog post, I showed you how to use WorkloadTools to replay a workload in two different scenarios. However, there is a third scenario that is worth exploring: the real-time replay. Before we jump to how, I’d better spend some words on why a real-time replay is needed. The main reason is the complexity involved in capturing and analyzing a workload for extended periods of time. Especially when performing migrations and upgrades, it is crucial to capture the entire business cycle, in order to cover all possible queries issued by the applications. [Read More]

In my last post, I described how to capture a workload to a file, in order to run a replay against your target environment at a later time. Well, that later time has come and you’re ready to roll. Of course, WorkloadTools has got you covered. Before I show you how SqlWorkload can run the replay, reading all data from the workload file, I need to spend some time describing how to set up your target environment. [Read More]

If you ever tried to capture a benchmark on your SQL Server, you probably know that it is a complex operation. Not an impossible task, but definitely something that needs to be planned, timed and studied very thoroughly. The main idea is that you capture a workload from production, you extract some performance information, then you replay the same workload to one or more environments that you want to put to test, while capturing the same performance information. [Read More]

A couple of weeks ago I posted a method to convert trace files from the SQL Server 2012 format to the SQL Server 2008 format. The trick works quite well and the trace file can be opened with Profiler or with ReadTrace from RML Utilities. What doesn’t seem to work just as well is the trace replay with Ostress (another great tool bundled in the RML Utilities). For some reason, OStress refuses to replay the whole trace file and starts throwing lots of errors. [Read More]

It’s been quite a lot since I last posted on this blog and I apologize with my readers, both of them :-). Today I would like to share with you a handy script I coded recently during a SQL Server health check. One of the tools I find immensely valuable for conducting a SQL Server assessment is Glenn Berry’s SQL Server Diagnostic Information Queries. The script contains several queries that can help you collect and analyze a whole lot of information about a SQL Server instance and I use it quite a lot. [Read More]