HAProxy Community Edition is a free, open source reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is presented as suited for very high traffic web sites.
It prevents a single server failure from being a downtime event by adding redundancy to every layer of your architecture. A load balancer facilitates redundancy for the backend layer (web/app servers), but for a true high availability setup, you need to have redundant load balancers as well. So it is well suited for all production related servers and less suited for individual servers that do not require redundancy.
Microsoft SQL is ubiquitous, while MySQL runs under the hood all over the place. Microsoft SQL is the platform taught in colleges and certification courses and is the one most likely to be used by businesses because it is backed by Microsoft. Its interface is friendly (well, as pleasant as SQL can be) and has been used by so many for so long that resources are freely available if you encounter any issues.
A few, rare times each year, HAProxy CPU utilization spikes to 100% and server has to be rebooted - this may be related to HAProxy OR it could be an external factor causing this.
Microsoft SQL Server Enterprise edition has a high cost but is the only edition which supports SQL Always On Availability Groups. It would be nice to include this feature in the Standard version.
Licensing of Microsoft SQL Server is a quite complex matter, it would be good to simplify licensing in the future. For example, per core vs per user CAL licensing, as well as complex licensing scenarios in the Cloud and on Edge locations.
It would be good to include native tools for converting Oracle, DB2, Postgresql and MySQL/MariaDB databases (schema and data) for import into Microsoft SQL Server.
We understand that the Microsoft SQL Server will continue to advance, offering the same robust and reliable platform while adding new features that enable us, as a software center, to create a superior product. That provides excellent performance while reducing the hardware requirements and the total cost of ownership of our solution.
It is very easy to use. I was able to find a lot of documents for it on the internet. Very good community support. There are lots of examples available to try. We mostly use a command-line user interface to interact with it. The CLI is also super easy to use and very easy to interact with
SQL Server mostly 'just works' or generates error messages to help you sort out the trouble. You can usually count on the product to get the job done and keep an eye on your potential mistakes. Interaction with other Microsoft products makes operating as a Windows user pretty straight forward. Digging through the multitude of dialogs and wizards can be a pain, but the answer is usually there somewhere.
We haven't used customer support. We mostly used the community version. We build a multi-node HAProxy cluster with HA to the proxy itself using opensource plugins available. With the support available on the internet and the documents available we don't need to use much customer support.
We managed to handle most of our problems by looking into Microsoft's official documentation that has everything explained and almost every function has an example that illustrates in detail how a particular functionality works. Just like PowerShell has the ability to show you an example of how some cmdlet works, that is the case also here, and in my opinion, it is a very good practice and I like it.
Other than SQL taking quite a bit of time to actually install there are no problems with installation. Even on hardware that has good performance SQL can still take close to an hour to install a typical server with management and reporting services.
We chose HA Proxy because it is cheaper than a hardware balancer, it is an open-source solution with a large community behind it and with constant updates. It also allows custom scripts according to needs.HA Proxy is a solution used in many internet sites like GitHub, Reddit, Twitter, and Tuenti.
[Microsoft] SQL Server has a much better community and professional support and is overall just a more reliable system with Microsoft behind it. I've used MySQL in the past and SQL Server has just become more comfortable for me and is my go to RDBMS.
Significantly lower investment vs competitors. In the case of F5s we have Virtual Editions so we're paying for the hardware to run it on top of the several thousand dollar licenses that are required for each pair and we currently have a pair of F5s per client so there's a huge potential for cost savings there.
Requires our network engineers to learn a new skill or our Systems engineers to take on the responsibility of managing the load balancers. It's not a huge difference either way, but it does impact the way we have done business in the past.
Increased accuracy - We went from multiple users having different versions of an Excel spreadsheet to a single source of truth for our reporting.
Increased Efficiency - We can now generate reports at any time from a single source rather than multiple users spending their time collating data and generating reports.
Improved Security - Enterprise level security on a dedicated server rather than financial files on multiple laptop hard drives.