is there any guide how to determine correct HW requirements of PAM installation? I've found only minimum HW requirements in Installation Guide.
So far we are using PAM processes that do some actions and job is done after a few seconds. Using this usage model we can handle thousands of PAM processes without problem during a day. Now we need to create also PAM processes that contain approval user task. Such user task can wait for a user interaction for a few days. Because of our users number I expect thousands maybe tens of thousands of such PAM processes waiting for user interaction. These PAM processes are in "Waiting" state. Is there some big differences in resource consuming between "Running" and "Waiting" status? How to determine correct HW requirements?
It is very difficult to give you a guide as to the amount of hardware you are going to need to power your Process Automation engine. As a development tool, Process Automation's hardware footprint will be very much dependent on what you develop within it.
In the Support team we generally recommend a 2 PAM node cluster installed on a Server with at least 8gb of memory and 4 CPU on each as a solid starting point for a Production environment.
This should be able to handle a relatively decent load, provides load balancing and failover capabilities, and will work for a large part of our customer base.
But we also have clients that are pushing the limits of a 4 node cluster. In general these clients have a large number of instances in non-completed states waiting for interaction from an end user in a task, or for some external action to be completed.
Every non-complete, actively running instance in PAM has a memory footprint and takes up at least a small amount of CPU cycles for PAM to maintain that instances current state in preparation for it to move onto the next state.
Waiting instances have a smaller memory footprint than actively running instances, but again that footprint is largely dependent on what the instance is designed to do. If it is a small process that is just waiting for an approval task, you may find that you can easily have ten thousand of them waiting in a 2 node environment; if they are very large complex instances that are waiting then a 2 node cluster may not be up to the task
PAM has a number of wait to help keep the number of actively running instances down. For example you could have a very small process that is the waiting instance for the task that then takes the feedback from the task once it is completed, and launches the much more complex process to complete the work.
You could engage a Services Architect, who could review your process definitions, assist in their design, and review both current and future requirements to make more specific hardware recommendations; but it may be as easy to load up your test environment with this newly designed process and see how well it performs and make adjustments and add clustered nodes is necessary.
thank you for your explanation.
Thanks for sharing this MICHAEL NIEBUHR.