By David Gallant, VMWare Professional Services Consultant
Ok so you’ve decided to virtualize your Tier 1 Business Critical Applications, awesome that’s great news. The daunting question is “Where do you start?” As a VMware PS Consultant, I see customers go through this process every day; some customers get us involved when that question comes up, others get us involved much later. I can say with certainty earlier is always better than later. Tier 1 application design and architecture it is hardly ever business as usual, but it had better be business as usual when you finish!
So, where do you start?
Without a doubt I always start with something I call “Workload Classification.” It’s the phase where the virtualization architect or administrator works with the application teams to understand 3 aspects of enterprise application architecture.
- Application dependency planning (Enterprise Architecture)
- Understanding the performance profile
- Defining the security profile
We will explore these tenets deeper in upcoming blogs for this month, so I’ll start by talking about the core classification work.
When classifying workloads for virtualization the first instinct is to collect as much data as possible. That would be incorrect, instead think about the 4 components we measure for vSphere: Compute (CPU and Memory), Storage and Network. I recommend only collecting data on these areas to start as it makes our work much simpler to gather and analyze this data.
- CPU collect Utilization by percentage and by MHz at the server level, instance/process level and database level when measuring databases.
- Memory collect utilization by percentages and some measure of bytes (KB, MB or GB).
- Storage collect IOPS, throughput, Storage consumed, and growth rate.
- Network collect percentage, keep in mind you need to know the link speed of the target and source to match them up. If you want to go deep use a tool like Wireshark to measure the individual application
Collect the data for a period of time (typically 4 weeks). I like to use ends of quarters when possible so I can see trends in larger data spikes. Further, the fiscal year end is the best time, especially when trying to classify finance applications like SAP ECC. Also think about the data collection interval, the amount of frequency of when you grab a data point. I typically use 1 minute intervals for most workloads, but a smaller interval may be necessary for a high performance / low latency application. If a smaller interval is the case, reduce the period so as to limit the amount of data you’ll have to analyze and instead consider two or more collection periods.
Once you have your data; analyze it against the target hosts’ specifications to determine how many hosts are required and some initial placement strategies. Remember vSphere DRS will help with final placement and keep the load balanced, so think of this as a theoretical exercise to help architect and design the environment.
After the workload classification study is complete I always compare my results to an Application Dependency Plan; the two studies together should provide an excellent basis for a migration or re-platform study. Another piece of the puzzle is defining the security profile of the target environment, comparing and contrasting the existing security profile versus the future state one. There are tremendous advantages to implementing proper security in the vSphere environment that we will describe in a future blog this month.
I’ll leave you with some final thoughts on workload classification. If done ahead of time, going through this process will not only guide the design of the future environment, but will probably help define a new optimized way to go to market for your business critical applications. You will probably find business level design flaws in your current environment that when changed, will allow you to more easily manage, maintain, optimize and scale up and/or out in the new environment.
If you’re thinking of virtualizing your business critical applications and you’re not sure where to start, contact your account team and get us involved today.
|David Gallant has worked at Vmware for over 2 years with over 20 years experience in the IT industry. He specializes in Virtualizing SAP, Microsoft SQL Server and Oracle Non-RAC.|