If you are curious about the number of Trend controls you can run against your CSWorks
server infrastructure, you may find this post interesting. We will make minor changes
to historical data server configuration, run a few Trend control clients against it
and analyze what we see.
Environment
CSWorks 1.2.3800.0
Server: Intel Core 2 Duo @ 2.40GHz, 2 GB RAM, Windows Server 2008
Client: Intel Core 2 Duo T5300 @ 1.73GHz (notebook), 2 GB RAM, Windows XP SP3
Network: Wireless 54 Mbps
Server Configuration
1. As usual, we have to configure History Recorder so it uses some scalable database.
Install SQL Server 2008 Express on your server machine.
2. Create database "CSWorks"
3. Create HistoricalData table - see "createCommand" parameter of <dbtarget ...=""
name="Standard SQLServer DbTarget"> in CSWorks.Server.HistoryRecorderService.exe.config.
4. Configure SQL Server data source and make it active in CSWorks.Server.HistoryRecorderService.exe.config:
<dbTargetConfig>
<dbTargets activeDbTarget="Standard SQLServer
DbTarget">
<dbTarget name="Standard SQLite DbTarget" ...
...
/>
<dbTarget name="Standard SQLServer DbTarget"
providerInvariantName="System.Data.SqlClient"
connectionString="Data Source=localhost\sqlexpress;
Initial Catalog=CSWorks;user id=sa;password=...;"
...
/>
</dbTargets>
</dbTargetConfig>
5. Configure HistoryReaderWebService to read historical data from this database. In
the web.config, assign SQLServer target to the primary partition and specify correct
connection string:
<historyTopology>
<historyPartitions>
<historyPartition name="partition1" primaryDbTarget="partition1
Primary DbTarget (SQLServer)" secondaryDbTarget="">
..
</historyPartition>
</historyPartitions>
</historyTopology>
<dbTargetConfig>
<dbTargets>
...
<dbTarget name="partition1 Primary DbTarget (SQLServer)"
providerInvariantName="System.Data.SqlClient"
connectionString="Data Source=localhost\sqlexpress; Initial
Catalog=CSWorks;user id=sa;password=...;"
...
/>
</dbTargets>
</dbTargetConfig>
6. Restart HistoryRecorder service and verify that it writes observation to the newly
configured database.
Running clients
Before running the clients, make sure you have prepared *.clientConfig in CSWorks.Client.TrendDemo.xap
to run from a remote machine. Please see this
post for details.
Now run a few Trend clients on your client machine using this command:
start iexplore "http://myserver/CSWorksDemo/TrendDemo.html"
I ran 25 instances, increasing the load by 5-instance chunks.
Results
All 25 clients run without problems, trending data (both live and historical) arrives
without delays, server seems to be perfoming fine. Here
is a screenshot made on the server machine. Clients consume about 200K of live
and historical data every second, server machine uses about 35% of its CPU capacity.
SQL Server and ASP.NET worker process are working hard (14% and 18%, respectively)
to deliver historical data to the clients.
The spikes in data transfer rates mark moments when Trend control were re-querying
bigger amounts of historical data - View->Tracking setting were set to On for all
Trend control instances, and all instances were refreshing the whole picture synchronously
(well, in chunks of 5 instances, of course).
The spikes in CPU consumption mark moments when I ran chunks of 5 IE instances.
Summary
Not bad for a commodity server box that runs every piece of the deployment: all CSWorks
services (LiveData, Alarm, HistoryRecorder), web services and database engine. Potential
bottlenecks are:
- the database - not surprising;
- web service layer - but we can scale it out using web farm.
