This week we have been learning about Tableau Server. Yesterday consisted of an introduction followed by a series of exercises practicing server installation, back-ups, restores and finally deleting Tableau Server. Today we took a deep dive into how Tableau Server works. This was a really interesting day and I was frantically trying to scribble down as much as possible whilst also trying to picture and understand what was being said. If only we could do two things at once!
Which conveniently brings me onto today’s Tableau Tip: Virtual Machines. I first came across these at University in the form of the popular VMware. Attempting to do some modelling for my Physics degree, at the bottom of my rather long list of questions was why the need for a virtual machine? Sure it was pretty cool but I didn’t really understand the benefit of using one, let alone lots of them.
One of the main benefits is it allows us to create a virtual computer within, and wholly independent of, the operating system (OS) and allows us to apportion specific amounts of CPU and RAM to the VM depending on the processes it is running. Crucially if we run several Virtual Machines simultaneously, we can allocate different amounts of CPU and RAM for the different processes they run. The benefit of this is that Virtual Machines can potentially produce significantly higher usage on the physical servers than those running without VMs. In short we can potentially get more stuff done per unit time enabling considerable financial savings. We have to assume however that the VMs will not use all their resources all the time otherwise the system would fall over. It also helps to split out the different applications out into their own environments as there is less opportunity for conflict.
We can see a basic example above of how the physical hardware can be split up onto the virtual machines. In the example above, the second virtual machine contains a 2 core CPU and 2GB of RAM whilst the first virtual machine only has one core. If both Virtual Machines were maxed out then the whole system would collapse due to insufficient memory.
High availability is a measure of how much of the time a server is available for, or put another way when it is not on down-time. Different organizations have different tolerances for downtime but the higher the availability, the higher the tableau memory requirements for the clients servers and therefore the greater the cost to the client in terms of investment in physical hardware. Virtual Machines are therefore a great way to lower the cost of investing in physical hardware.
Another benefit of Virtual Machines is that they act totally independent to the machine they are running on. This means we can work on them safe in the knowledge that we cannot damage or edit the machines physical OS or files.
We used Virtual Box as our VM and the download link is:
Deleting a Virtual Machine has no impact on physical hardware either. As previously mentioned, VMs run their own operating system and we can run all the usual applications that we would run on our normal physical machines.
In short VMs are great tools, and help you make more of your machines processing power safe in the knowledge that they are totally independent of the physical hardware.
