Random option

Using the random option, application servers are picked randomly.

If the Web server is using multiple process threads to send requests to the application server and depending on the workload, random selection can sometimes yield a more even distribution of work across the cluster.

To set request routing, follow this WAS Administration console path: Web servers > web_server_name > Plug-in properties > Request routing.

The load balancing options had been tested with the ECM workload used for this study at a high load level.

Figure 1 shows the average ICN transaction response times for the two possible load balancing options.

This graphic provides an overview of the load balancing options for Web server request routing — Figure 1. Load balancing options for Web server request routing

For both load balancing options the average ICN transaction response time was similar, however the round robin option showed a slightly better response time than the random option.

When looking at the CPU loads as an indicator for the load distribution of the ECM nodes, it appeared that the loads were slightly more unequally distributed than was the case using the random option. Every ECM node used around 5 IFL processors at the highest ECM load level.

This graphic provides an overview of the load balancing options for ECM node CPU loads for Web server request routing — Figure 2. Load balancing options for ECM node CPU loads for Web server request routing

Because the round robin option produced a slightly better equal load distribution, it was considered to be more suitable than the random option for our type of workload.

For the SUT: The default load balancing option round robin was used for the case study measurement series.

For information about IBM WAS cluster workload management, proceed to the WebSphere Application Server documentation at the IBM Knowledge Center:

https://www.ibm.com/docs/en/was-nd

Then search for the topic: Balancing workloads.