How to use Windows Media Load Simulator for Windows Media Server performance testing and monitoring

Windows Media Load Simulator (WMLS) has two main uses: as an extremum or as a stress test tool and on-line monitor.
1 extremes and pressure pressure tests: You can test offline servers at the desired extreme pressure conditions and analyze the results. After that, gradually increase the pressure and pay attention to the performance of the server and streaming media playback quality, gradually reached the limit of server capacity. You can use the test results to set the maximum number of client connections for the server. You can use WMS's management interface to set the maximum number of customers, maximum bandwidth usage, and maximum file bit rate.
The test results typically reveal the server's problems, CPU, memory or hard disk or network bandwidth. For example, a slow CPU can result in high CPU usage and a correspondingly low number of user connections, and result in a large number of pending connections and streaming errors. The late send counter also describes the vulgar CPU. A low-speed hard drive will cause late send under pressure. However, when the server transmits real-time media content, the data must be available at the time of transmission.
2 Online monitoring When the server is officially online, you can use one or two users to connect to your server to monitor the overall performance of the server. You can also create a simple program or script that automatically generates warning logs or messages. For example, open your eyes and create a simple script to email you when WMLS monitors a streaming error .

Use WMLS to help you determine and maintain server performance based on the following procedure, including a few aspects
1 Determining customer scenarios
2 Creating a Test source file
3 Configuring the Limit test
4 Configuring WMLS
5 to test
6 Configuring online Monitoring

1 Determining customer scenarios
Before testing, you need to determine the typical number of extreme customers and typical customer scenarios. The typical limit customer count refers to the ability to stream media simultaneously in a normal situation

Maximum number of users. The customer scenario is based on the type and mode of transmission of the content. Customer behavior (such as search play, open and close streaming) and authorization require additional server resources, which also need to be considered in a complete simulation test. Because you are not able to judge the limits of the server before you actually go online, you should set your expectations to be slightly higher than you actually feel when you perform a simulation test. When you determine the number of customers and the scene, consider the following factors:
A. Number of simultaneous connections: What is the average number of customers and the maximum number of customers connected to the server at the same time?
B, broadcast and on-demand hybrid: What type of content do you provide? How much is broadcast? How much is on demand?
C, user behavior: How will the user play the content? Do you expect users to start at the end or just browse the content?
D, mixed bitrate content: How much content is encoded with mixed bit rate?
E, authentication: Do you need a user name and password to access content?

3 Configuring the Limit test environment
The limit and stress tests should be performed offline with a closed LAN environment. WMLS can create the same number of customer connections to the server pressure and network load as the real case . If you perform stress testing in a real-world network environment, testing can potentially take up all available bandwidth and prevent real customers from accessing the server. And in a closed LAN for limit testing, you can avoid users encounter network or Internet interruption, and you can arbitrarily increase the bitrate as needed to test the server and local network hard pieces. A typical LAN layout is shown.

Figure 1. Layout of closed LAN for stress testing
This layout assumes a typical test scenario: a Windows Media server capable of withstanding 1000 simultaneous 28.8kbps streaming connections, 5 clients connected to the server and transporting wmls, each client simulating 200 client connections. The layout diagram also contains a remote encoding computer for streaming live and a remote storage drive for storing on-demand file data sources.

    clients running WMLS must handle a certain number of client connections smoothly. The number of connections depends not only on the number of simulated customers, but also on the content's bit rate and network bandwidth. For example 200 users connected to 28.8kbps of streaming media will consume 5.6Mbps of bandwidth, which is easy to withstand in a 100M Ethernet environment. However, if the file content is transmitted at a speed of 300kbps System Monitor to check the client's CPU and memory usage to ensure that usage is less than 50%. An overloaded client generates a stream playback error that affects the test results.

fast servers can withstand higher volumes of streaming media connections. For example, a server with 4 processors and 1G of memory can withstand the simultaneous connection of thousands of users. In this case, you should add more analog client connections or use a faster client. The usual experience is that each Windows Media server uses 3 clients. The ratio of 3:1 applies to the configuration of the guest machine as well as the server. If you are using a client with a lower configuration than the server, then you need more clients. In general, make sure your network and server are configured correctly when testing with WMLS.

You can use a 2003 Network Load Balancing cluster to increase the stability and reliability of your server. A load-balanced system is a cluster of servers, but it is a single server for the customer. You can test a clustered server like a single server.

You can also follow the Windows Server 2003 Scalable Networking Pack to free up CPU cycles to run application-related tasks, such as supporting many customer connections and increasing the network throughput. (Scalable networking automatically included in Windows Server 2008)

4 Configuring WMLS
A. Enable the Windows Media Server for load testing
Create a file named wmload.asf under the root of the WMS system to protect your server against unauthorized load testing.
B. Configure specific Windows Media Server information
C, configure the specific data source
D. Configuring Customer Profiles

E. Add authorization
F, set test time and enable logging

5 to test
A, running limit test
Run the test for at least 2 minutes to check the following information:
Focus on counter statistics for WMLS
Note the number of lost packets that reach the limit number of customers
Check the number of test errors counter
B. Analysis results
C, the pressure test

6 Configuring online Monitoring

Once you have a stable server configuration, you can put your system into production and continue to use WMLS for online monitoring. You can configure a two-day client, one to connect to a server on a local area network, and one to connect to the server via the Internet. Such as:

The purpose of using online client monitoring is to ensure that the server is working properly in a production environment. You shouldn't stress-test the online servers in your production environment, either through the Internet or with a network that other people really use. WMLS will quickly consume all of the bandwidth, which will affect the use of other real customers. Online monitoring is to ensure that the server and network performance is normal, usually through a typical client to connect to the server. The test results obtained using WMLS offline are equally valid for online servers.

You can also use a simple program or script to enhance the online customer monitoring, which requires the client's registry configuration. See the Windows Media Help file for details.

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How to use Windows Media Load Simulator for Windows Media Server performance testing and monitoring