DyKnow Server

Server Specifications

Detailed Windows Application Server Requirements

The DyKnow Application Component is supported on most editions of Windows Server 2003. Support will be added in the future for Windows Server 2008. DyKnow recommends the use of Standard, Enterprise or Data Center Editions of Windows Server 2003. As installation needs grow, the server administrator may find it advantageous to utilize the 64-bit editions of Windows Server to allow for the utilization of more RAM.

DyKnow is installed on the Default Web Site on IIS for the application server. Installing the DyKnow Application Server on a machine that is already running web applications on its IIS server may cause problems. This is due to unknown configuration changes that other web applications may make or require to IIS. Therefore, DyKnow does not support or guarantee that the DyKnow Application Server will work in IIS with multiple web applications. DyKnow encourages the exclusive installation of the DyKnow Application Server on the IIS server. If the customer plans on using SSL communications, the DyKnow Application Server does not support the use of self-signed SSL certificates.

Detailed SQL Database Server Requirements

The DyKnow Database Component is supported on several editions of SQL Server 2005. Support will be added in the future for SQL Server 2008. The DyKnow Database component must be installed on SQL Server 2005 Workgroup, Standard or Enterprise Edition. Larger deployments should consider using 64-bit versions of SQL/Windows Server for additional scalability. Both the Standard and Enterprise editions of SQL Server can utilize the maximum amount of RAM supported on the host Operating System, which is as high as 32GB for Windows Server 2003 x64 Standard and 2TB for x64 Enterprise. SQL Server Workgroup edition is limited to utilizing 3GB of RAM, and is 32-bit only. Workgroup should be considered only if the customer already owns a license of SQL Server Workgroup Edition.

The server administrator should consider using dual or quad core processors on their SQL Server as a single processor license may be used on a single socket muti-core processor. For more information on SQL Server Licensing please see the section entitled: Microsoft CAL vs. Processor licensing

The DyKnow Database Component must be installed to a “default” instance of, and not a “named” instance of SQL Server. It also requires the use of “Mixed Mode Authentication” and the SQL Server Agent service be enabled and running.

The DyKnow Database Component does not install and is not supported on Microsoft SQL Express or any other Database platform besides Microsoft SQL Server.

VMware Support

Virtualization is a proven software technology that is rapidly transforming the IT landscape. For those interested in using VMware, DyKnow supports VMware ESX Server 2.5.5 (or later) for the DyKnow Database and Application Servers. The system resources solely allocated to the Virtual Server must at a minimum be equal to the resources required above. Due to the DyKnow Server’s usage pattern, any Virtualized configuration that shares the required resources allocated to the DyKnow server with other servers may experience sub optimal performance. DyKnow does not recommend or support configurations that do not meet the above requirements.

Data Storage and Disk Space

The DyKnow Server stores all of its information in the SQL server database files. This allows for easy backups and restoration of all data should the need arise. This information stored includes user information, class information, and saved notebooks. DyKnow uses a kind of SORM (Store Once Read Many) mechanism for storage of images and other large data objects. This method drastically reduces the amount of duplicate data stored on the DyKnow server thereby reducing the amount of disk space needed by the database. The amount of data stored on a DyKnow server can vary from institution to institution depending on the amount and type of DyKnow notebooks used by the institution. One simple calculation that can be used as a rough estimate for disk space is: 2G (Base) + 1G per 5 classes with approximately 25 students per semester. The DyKnow administration console allows the administrator to dictate how long past information is stored in the database and thereby can effectively monitor and control the size of data storage.

For customers utilizing the Audio Recording functionality in Vision 5.1, administrators should plan for 12MB of storage for each additional hour of recorded audio.

For customers who have only purchased the Monitor product data storage requirements are lowered as there are no student files saved to the DyKnow database server. Customers in this scenario should plan to allow up to 2GB for the database.

Network Particulars and Performance

Any DyKnow client communicates only with its DyKnow server. The DyKnow suite of applications does not utilize any peer-to-peer technology to facilitate communication. Also, the DyKnow client and the DyKnow server communicate only via http (port 80) or https (443) based on the setup by the institution administrator. This means that DyKnow can be setup and used in almost any local or distance based networking environment. DyKnow usually needs no additional networking support or firewall configuration changes to operate.

The DyKnow client communicates with the DyKnow server only when it needs to and using small data messages. The DyKnow client also caches any commonly accessed data and usually only requests the changes to that data. What this means is that DyKnow is a low network bandwidth application requiring no special high speed networking requirements in classroom environments. Bandwidth utilization for the “View Screen”, “File Transfer” and “Broadcast Screen” features is higher and must be taken into consideration if the customer plans on using that functionality extensively. DyKnow also utilizes special “lost signal retransmit” (LSR) technology. Because of this, the DyKnow Client functions over wireless networks (i.e. 802.11B and 802.11G) and over the internet from broadband cable or DSL connections without worrying about port forwarding or NAT. When implementing a school or district wide implementation of DyKnow please refer to the WAN Requirements and Larger Installation Needs section.

DyKnow's product suite is client-server based and therefore requires all client-server transmitted messages to flow uninterrupted. Introducing devices such as packet shapers and web filters into the client-server message path can cause communication failures that disrupt network traffic to the extent that DyKnow applications fail. DyKnow does not support making these kinds of devices work within a DyKnow client-server environment. If used, then these devices must allow all "DyKnow server bound" traffic to bypass them or to pass through them "untouched".

WAN Requirements

While the core functionality of the DyKnow Client uses very little bandwidth, the customer must take external bandwidth into consideration when utilizing a remote DyKnow server – either a centrally located server in a district or campus datacenter or when utilizing the DyKnow ASP.

For up to 500 concurrent users DyKnow recommends a minimum of 10Mbps up/down bandwidth. This will allow for sufficient bandwidth when transmitting multimedia files to clients, which is subsequently cached on client computers. The average bandwidth usage for a scenario with 500 concurrent users will be approximately 4 Mb/s, but will peak up and down as usage varies from implementation to implementation.

For larger installations, administrators should plan on linear scaling of minimum bandwidth usage, with additional bandwidth available for higher bandwidth activities such as image transfer and audio file transfer, and when using features such as Broadcast Screen, View Screen / Remote Control and File Transfer.

Single (Combined) Server Scaling

2 GB RAM / Single Core Processor = 150 concurrent users

4 GB RAM / Dual Core Processor = 500 concurrent users (64-bit recommended)

HDD = 2GB Base + 1GB for every 5 classes with 25 students

Customers planning on utilizing the new 5.1 Vision Audio Recording functionality should plan for 12MB of storage for each hour of recorded audio on the database server. Audio data can be purged each semester to manage database size.

Note: These values represent a sample server estimate. Factors such as network and server IO performance may alter these values.

Larger Installation Needs

There are several basic methods of increasing performance for large installations.

If both the DyKnow database and application servers are the same machine, then they can be separated onto separate hardware. This separates the DyKnow servers into two distinct processes: The DyKnow Database Server and DyKnow Application Servers. The DyKnow Application Servers process with IIS and would be the servers that the user connects to. Those servers can be load balanced via Round Robin DNS or any other low tech methods of load balancing.

When performing higher tech load balancing it should be noted that the DyKnow Application Server has two stateful components and one stateless component. The server administrator may use the ASP.NET state service to help perform load balancing. Customers with larger implementations should consider a 64-bit only infrastructure for improved scalability. This would include a high performance 64bit SQL Server with multiple DyKnow Application Servers. Large scale implementations should also consider using SQL Server Enterprise and Windows Server Datacenter edition to allow for utilization of more processing cores and RAM per machine, along with improved backup and failover capabilities.

Architecture Support

There are two basic server architectures currently available, either 32-bit (x86) or 64-bit (x64). When setting up a server environment to run the DyKnow Server in a combined server configuration, the architectures of the various installed software components must be the same. For example, if you are running 32-bit Windows Server 2003, you must also run 32-bit SQL Server 2005 and the 32-bit DyKnow Server. The same holds true if running a 64-bit instance of Windows Server 2003. In this case the instance of SQL Server 2005 and the DyKnow Server must both be 64-bit (x64).

If you run the DyKnow Application Server and the DyKnow Database Server on multiple (separate) servers, the individual servers must follow this format but the architectures do not have to be the same between the separate physical servers. For example, one could have a 32-bit (x86) DyKnow Application Server connecting to a 64-bit (x64) DyKnow Database Server and vice versa.

The following chart helps show the various combinations of server architecture(s) that DyKnow supports.

Microsoft CAL vs. Processor licensing

Microsoft Windows Server 2003 and Microsoft SQL Server 2005 each has three different licensing models. Two of the models require CALs (Client Access Licenses) and the third model is a Processor License. For a typical Server installation that will only be running the DyKnow Server, a Microsoft Windows Server 2003 license with 5 user CALs is sufficient. Microsoft SQL Server 2005 needs to be purchased using a Processor License. The reason for this difference is due to the fact that each user that signs onto the DyKnow Server would also need a corresponding CAL for SQL Server 2005 and thus in most situations would be more cost prohibitive than the Processor License.

The current Microsoft SQL Server licensing specification licenses a processor license per “socket”, so a single processor license can be utilized on a “Quad Core” processor. For more information please visit this Microsoft Website: http://www.microsoft.com/sql/howtobuy/licensing.mspx,specifically Section 3a of the Server Processor End-User License Agreement (EULA).

A Standard Edition Processor license is available from your preferred education vendor for under $1500. Email sales@dyknow.com for details.