Tuesday, August 25, 2009

24 Hours of PASS

If you haven't already heard, PASS is hosting 24 hours of PASS on September 2nd. These are a series of free, one hour long webcasts on a variety of SQL 2008 subjects. You can check out the schedule on the PASS website. The first webcast is actually at 7 PM on September 1st Central Time. It's not too late to register.

Friday, August 21, 2009

First look at SQL 2008 R2

I’ve started to install the CTP of SQL Server 2008 R2. The first change I ran across was this screen during installation. I don’t have a copy of SharePoint Fourteen(?) so I chose the more familiar SQL Server Feature Installation. I’m installing this on a virtual server so I can always change options later.


Thursday, August 20, 2009

Replaying traces, Part 5

So I’m now testing my workload on a virtual 64 bit server, again hosted by VMWare, again with only 4 CPUs. And again I find more issues.

I ran this replay 3 times so far. All three times the replay appeared to have hung at the 99% mark, similar to the 8 CPU physical test. The only difference was that, for the final test, I didn’t save the results to disk. I did this because on the second test there appeared to be SQL activity that was suspended by the TRACEWRITE wait type. The drive it was writing to was the only virtual drive; all databases are on SAN storage.

While all three hung at the 99% mark after about 3 hours, each test had different results. The first test was showing transactions against the database throughout the trace (the black line. The blue line is % Processor Time, the yellow line is % Privilege Time, the red line is transactions/sec against tempdb). The Processor time showed activity from the Profiler after the 99% mark .Test 1
The second trace showed no transactions after the 99% mark. This is the one that showed the TRACEWRITE wait type. Notice that there are no transactions against the db after the 3 hour mark this time.Test 2  
Test 3 shows the same pattern as test 1. There were no wait times for tests 1 and 3.Test 3

There is one more issue with these three tests. After stopping the replays, I had to manually kill the Profiler process because profiler became unresponsive. The third test stayed alive and was stopping the process and I let it go. However the next morning I checked and it was still “stopping” after 13 hours. And the Profiler was still responding.

The more I run these replays the more confused I get. I’m going to try one more time. This run will be from a remote machine, I’m only going to capture the counters on the virtual server.

Friday, August 14, 2009

(Mostly) disappointing meeting

Last night I went to the monthly meeting of the Chicago SQL User group, held on the second Thursday of the month. You can check them out and register for meeting notifications here. This is a good resource for anyone wishing to attend. Anyway,there were two topics last night. The first was on SQL and Powershell, the second on clustering with SQL 2008 and Windows Server 2008.

I don’t have any experience with clustering since we don’t use it at work but it’s one of those topics I feel I should know more about. But last night I was really looking forward to the discussion on Powershell. I’m looking for reasons why I should use Powershell over other methods like SMO or WMI to monitor servers I’m responsible for. I wanted to see some amazing Powershell cmdlets in action.

Unfortunately the presenters of the Powershell segment were not prepared very well. It started with having problems connecting a laptop to the projector and went downhill from there. The demos were filled with errors; most flatly didn’t work. The first presenter dwelled too long on the basics of Powershell itself, the second barely did more than read from the slide deck. Their presentation ate into the second segment on clustering. I wonder if their book was written better.

The second presenter did a much better job. He knows his topic extremely well, being a Microsoft MVP on clustering, and you can tell he is passionate about the subject. And he’s an effective speaker. But since he didn’t have much time he had to cut his demos short.

Don’t get me wrong, I appreciate everyone who presents at these meetings. It’s not easy getting up in front of a room of 80 strangers and talking about a deep subject in a short period of time. I just wish they could have presented their material in a more effective manner.           

Wednesday, August 12, 2009

SQL Server 2008 R2 CTP is now available

Earlier this week Microsoft announced that the first CTP for SQL Server 2008 R2 is available for download. You can get a copy through TechNet or MSDN, or on the site page here.

According to Mary Jo Foley, R2 is tied tightly in with the upcoming Office 2010 release. Both can be expected in the first half of 2010, around May or June.Personally I’m hoping for April, before my TechNet subscription runs out.

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Replaying traces, Part 4

So far we’ve replayed the same workload on 3 virtual servers, each with 4 CPUs, and 3 physical servers, 2 with 4 CPUs and 1 with 16 CPUs. We also ran one with 8 CPUs but that replay appeared to hang at 99%.

All the physical replays showed the same trends. A 16 CPU server performed better than 4 CPUs, Hyper-threading off performed better than hyper-threading on. The average for IO and transactions/sec followed the same curve; the longer the replay time the lower the average.

But the virtual server replays showed a different trend. All of these completed in less time

than the 4 CPU tests on a physical server. And the averages for IO and transactions/sec were noticeably less. Since the workload was the same in each case we expected the averages to be consistent with the trend set by the physical since the total number of transactions and IO should have bee the same across the board.

I’m guessing that there were more deadlocks on the virtual than the physical. In all cases the CPU usage was the same, averaging higher than 80%. If deadlock victims are rolled back it would explain the decrease in total IO. But I don’t know if a rolled back transaction is still considered a transaction by the Windows counters. This is going to take some research.

We have some more tests scheduled using a 64 bit virtual server and one test using VMWare’s newest host that supports virtual servers running 8 CPUs. 

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Wednesday, August 5, 2009

SQL Server 2008 Training Kit is available

One of the things I like about Microsoft is the wealth of training they make available for their products. There was a training kit for ASP.NET, one for Visual Basic 2008, and now there’s one for SQL Server 2008. You can get yours at http://www.microsoft.com/downloadS/details.aspx?familyid=E9C68E1B-1E0E-4299-B498-6AB3CA72A6D7&displaylang=en