Cluster Architecture

In nGrinder version 3.1, we introduces nGrinder controller clustering, which make the performance test can be executed in multiple controllers with better controller performance and support multiple set of agents(named region) to be used.

Below is the architecture without cluster supports.

1. nGrinder uses an embedded svn server(SVNKit) to manager our script file. And the svn repositories are saved in file system in ngrinder home directory.
2. nGrinder uses EhCache to improve the performance of getting data from DB and SVN repositories.
3. nGrinder uses Spring Security to protect the system and uses the Atlassian Plugin Framework to provide the extensibility.

If you enables custering mode by configuring the system.conf(See link) and install nGrinder into multiple machine,
the system architect is chagned as below:

1. All the controllers in the cluster shares the same DB and file system. For the ngrinder home directory ${NGRINDER_HOME}, we should set it on the network file system.
2. Each controllers will have its own speical properties and output folder for logging. This information will be service in ${NGRINDER_EX_HOME} in the each controller.
3. All controllers replicates the EhCache to each other, to make some data to be visible in all controllers in cluster.

Each controller can serve nGrinder web content equally but handles the different tests per region in the background.

We don't provide any session clustering by default. So you may suffer the login problem by the different session b/w controller. Because the session stored in a controller is not replicated to the other controllers. You may need to configure this by referring Tomcat Session Clustering Guide or using  the sticky session on L4. If you are not a expert on this, Just let users to connect only one controller. It's the easiest. :-)

How to configure the clustering? Check Controller Clustering Guide