Clustering Servers

For installations of more than 200 users, a hardware strategy that separates the database server from the web (and possibly the application) server should be considered. It is not typically necessary to separate the servers unless you foresee one of the following:

  • More than 100 users concurrently logged into the system
  • More than 50 users concurrently submitting requests to the system
  • You require a fault-tolerant system, with as much redundancy as possible

There are many permutations of database server / web server / application server plus potential other components for load balancing that can be used in setting up an ExtraView network to support a large number of users. Here are some examples, together with a list of the important points to consider.

Single Computer Environment

 


 

 

  Advantages   Disadvantages  
  Simple installation and configuration

Suitable for sites up to 1,000 users

   Not scalable for large numbers of frequent users

Not scalable for large number of concurrent connections

No redundancy in case of failure (but consider using mirrored disk drives for redundancy)

  

 

 

 

 

 

Multiple Web Server Environments

The following diagrams give examples of configurations. There are more possibilities and additional variants that can be configured, but it is unlikely they will give additional benefit to the ExtraView installation.

 

 

 

 

Variant 1: Web Servers and Application Servers on Single Computers

 

  Advantages   Disadvantages  
  Scalable solution to handle a significant number of concurrent transactions

Redundancy with failure of a computer with the web and application server

A single web or application server can be stopped for maintenance

   Expense of multiple web and application servers (although these each may be small, inexpensive computers)

Needs significant knowledge of server environments to set up and maintain

  

 

 

 

 

Variant 2: Web Servers and Application Servers on Separate Computers

  Advantages   Disadvantages  
  Most scalable solution to handle a significant number of concurrent transactions

Redundancy with failure of a computer with the web and application server

A single web or application server can be stopped for maintenance

   Expense of multiple web and application servers (although these each may be small, inexpensive computers)

Needs significant knowledge of server environments to set up and maintain