At Coeo we are seeing increasing numbers of customers take their first steps towards modernising their data platforms by moving workloads to the public cloud. Here is our quick guide to the options available:
When running on-premises, organisations have two options; running SQL Server directly on the hardware or virtualising the environment. Despite some reservations against doing this, most customers we work with have found that the flexibility virtualisation provides far outweighs the small performance penalty they pay (usually in the region of about 1-2% CPU and memory).
Virtualisation allows the customer to create logical separation of the environment. This means that they have more options in terms of running different versions of the platform to support an estate that is going through a modernisation process. It also means that, where we may have had a single large cluster while running directly on the hardware, when moving to a virtualised environment we can run on more (virtual) servers. This allows us to create a logical separation between different parts of the platform and makes the impact of maintenance or unexpected outage less for the users.
It is now rare for customers to keep an upgrade solely to on-premises, we see most of our customers take a hybrid approach to modernisation. Whilst the ultimate destination for many of the applications is Software as a Service (SaaS), the applications that differentiate the business tend to go to PaaS in the absence of a suitable SaaS alternative. Therefore, it is common for cloud modernisation to form part of an on-premises modernisation approach.
The Infrastructure-as-a-Service (IaaS) cloud-based model is based on virtualisation but differs from on-premises virtualisation in that the company has no control over the physical host or the hypervisor on which their virtualised servers run. However, they can still log in, install the software they require and need to patch it as required. Customers have a choice: pay for their SQL Server licence on a pay-as-you-go basis where the SQL Server license is incorporated into the cost of the virtual machine, or alternatively those with Software Assurance can exercise their License Mobility rights and use their Enterprise Core licenses to license virtual machines.
When moving to Azure SQL Database, administrators only have access to the database itself and not the underlying operating system and virtual machine. Azure SQL Database is Microsoft’s Platform-as-a-Service (PaaS) offering; typically, PaaS is cheaper to run than IaaS, which requires more infrastructure setup and fully licenced versions of SQL Server. We believe that Microsoft sees PaaS as the ultimate destination for its customers. Microsoft offers three services within the Azure SQL Database family:
The client deploys a single Azure SQL Database, which their applications connect to. There are two pricing options for buying a Single Database, the first being price in DTUs (a measure of performance that blends memory, CPU and processor). If performance hits the top of these quotas then the server will automatically be throttled, and performance will start to suffer. The other option is to purchase based on vCores and Memory, under the vCore purchasing model, which is essentially resource collection. Our blog post “New vCore purchasing option for Azure SQL Database” explains these options in more detail.The SQL Database option is particularly suitable for those looking to deploy a database from scratch. It’s useful for new web applications with short time to market constraints, as it can be set up very quickly.
Rather than having an individual database with a set amount of DTUs, or vCores, a company may decide to group numerous databases into a pool that share those resources. This is especially useful if the databases have different peaks and troughs in their usage. If they all peak at the same time they run the risk of being throttled as they will run out of the resources within the pool, so it may be more cost-effective to consider a Single Database in this case.
Microsoft’s newest offering; the customer has an instance of SQL Server they can deploy databases onto and a SQL Server Agent they can use to run scheduled jobs. It has been designed to simplify lift-and-shift
migrations while still providing many of the benefits of PaaS. However, unlike a virtual machine, users don’t have access to the underlying operating system, but can make limited instance level configuration changes. Furthermore, Managed Instance is priced by vCores only, rather than DTUs. This option can be expensive and therefore tends to be more cost-effective for companies running large numbers of databases. You can find out more about Managed Instances and the features included on Coeo’s blog.
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Coeo have published a short guide to data platform modernisation, which you can download for free from our website. Click the link below to get your copy.