Memory, what to monitor - Windows Server Capacity Management 101(10 of 12)

Today we’ll look at memory and what you should be monitoring.

Memory utilization of whole system- if need be look at process working set sizes to see who’s the “culprit”, this will show you which process is using the most memory and is a good way to detect memory leaks. A good rule of thumb for memory utilization is to have at least 10% left, this is to prevent excess paging which massively hurts performance.

Page file usage% - if this is high it means that you are regularly running out of memory and windows is having to use the page files.

Memory leaks - when an application dynamically allocates memory, and does not free that memory when it is finished using it, that program has a memory leak. The memory is not being used by the application anymore, but it cannot be used by the system or any other program either. Memory leaks add up over time, and if they are not cleaned up, the system eventually runs out of memory.

How to monitor
 
Thresholds – when setting a threshold a good place to start is 80% warning and 90% alarm, remember if you are seeing performance issues before hitting the threshold then the threshold should be adjusted. If constantly breached, reset the value or look for memory leak.

                    Memory Utilization report, example

Above is a good example of a memory leak, you can see that memory utilization is slowly creeping up then I restart the machine it drops down and then starts to creep up again.

I'll share some best practice recommendations for monitoring and managing memory on Friday.

Josh Worth

Consultant

Best practice recommendations - Windows Server Capacity Management 101(6 of 12)

So now we have gone over what we need to properly manage a windows environment, here are some best practise recommendations.

There are 3 main components to monitor in your windows systems:

·      CPU – physical utilization

·      Memory - usage

·      Disk – occupancy and performance

These are all components that if they fill up or are over utilized will severely effect performance.

Best practice recommendations - CPU 

What to monitor 

The first component to look at is CPU. When monitoring CPU you need to understand the difference between Logical CPU and Physical CPU, if your system is virtualized then it will be logical CPU as the windows environment does not know about the physical CPU it is being hosted on. 

·      If physical, CPU Total utilization of the machine - a physical system is much simpler as you are directly monitoring the physical components. 

·      If virtualized, CPU usage by the guest system - you will need to know the Physical CPU usage which is under the hypervisor. If you only look at CPU busy and it says 80%, it could be 80% busy of the 5% that has been allocated to it by VMware. You need to look at process level CPU busy. 

·      Process-level CPU busy; if virtualized gives a view of relative usage of the physical CPU busy from the host. It shows you how much CPU time each process is using, this is useful to see where all your CPU time is being used.

On Monday I'll be looking at how hard you can work a CPU.

Josh Worth

Consultant