EPiServer CMO in load balancing environment: simple scenario

Load balancing is a clear choice for the most of popular sites with high volumes of incoming traffic. This solution allows distributing the load among several servers to improve performance and achieve high availability.

This blog post describes а simple case of EPiServer CMO installation and configuration in the hosting environment where load balancing is applied to the web servers.

Let’s consider the following deployment model:

  • Web site based on EPiServer CMS is installed on two or more front web servers. The site is available publicly through the load balancing system, which spreads the work between those servers.
  • EPiServer CMS editor and admin UI is deployed on each web server and available through the load balancing system.
  • There is one back-end server which contains one shared site database.

The simplest deployment scenario for EPiServer CMO in this environment looks pretty similar to that one described in the previous blog post, the difference is that now we have several front web servers.

CMO Core, Statistics handler, web services and CMO UI are deployed on each front-end server. CMO database, Aggregation and Thumbnail services are installed on one back-end server, where CMS database is hosted. One CMO database is shared between all front-end servers.

EPiServer CMO in the load balancing environment: simple scenario

Please see the steps required to install and configure EPiServer CMO below.

Installing EPiServer CMO in the load balancing environment

1. Install CMO on all web servers where the site is hosted using EPiServerCMO.msi installer.

2. Deploy CMO on the site on the first web server using Deployment Center. Follow installation instructions.

Select Campaign Monitor and Optimization UI and Statistics Handler in optional components list to install:


Select or enter the name of SQL Server instance on your back-end server on database settings installation step.
Enter the name of new CMO database to create.

3. Deploy CMO on the site on other web servers.

Select the same optional components to install: Campaign Monitor and Optimization UI and Statistics Handler.

Choose SQL Server instance on your back-end server on database settings installation step.

Don’t create new database this time, select existing CMO database that was created on the previous steps.

4. Update configuration of sites where CMO was installed to support .NET 4 if it is required.

5. Configure CMO Live Monitor for multiple bindings.

6. Install and configure Thumbnail Service on back-end server manually.

Thumbnail service should be able to access the site through the load balancing system and all site resources that are required to create page screenshots. Make sure that Thumbnail service can be accessed from all web servers where CMO UI is installed.

Consider additional configuration if service is installed on Windows Server 2008 R2. Please see this blog post for more information about Thumbnail service.

7. Install and configure Aggregation service on back-end server manually. You can find installation instructions here.

Point Aggregation service to the CMO database that is used on the web sites.

8. Consider after-installation steps and notes.

9. Make sure that load balancing is configured to use sticky sessions, it is required by CMO UI.

More information

Please see the following blog posts and documents for more information:

EPiServer CMO components and simple installation scenario.

EPiServer CMO: advanced deployment options and manual component installation.

Page screenshots in EPiServer CMO and Thumbnail service configuration.

EPiServer CMO documentation.


Your feedback is highly appreciated. Please let us know how it works in your case.

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