How we migrate the platform from Webforms to Azure
Is it possible to move a platform written on Webforms in 2009 to the cloud with only slight changes?
If you ever wondered about it, this case will be super useful for you, as together with our clients we passed this way and have lots insights to share.
Our client is a scalable clinical trials database registry. It helps pharma companies and clinics, where new medicines are tested, prevent duplicate subjects, reduce protocol violations, reduce placebo rates, and improve safety.
The web application consists of a biometric system to authorize and track volunteers, the database where those records are stored, and custom solution for clinics to add new volunteers and check if existing ones are available for trials.
It is said that cloud computing
is a Klondike for any entrepreneur who
owns a software product with outdated technology.
But as you
know the way to this place isn’t easy,
especially if we talk about moving
legacy system to the cloud.
Let’s see
what challenges our team faced
throughout this project
System environment parameters
The whole system environment parameters were written to work on particular hardware, so moving it to the cloud as it is could break the whole system and threaten the security.
Database compatibility
The MS SQL database used in the solution wasn’t compatible with Azure SQL, so we had to upgrade it, and perform plenty of fixes.
Unsupported parts
Azure Firewall was incompatible with the current solution, as it recognized several harmless requests as vulnerable, that could stop the whole system work.
The more we dived into the project, the more curious challenges arose, so keep reading.
Let’s start from the very beginning, when our team familiarized the project for the first time. Even though the task seemed easy, we knew that migrating Webforms to Azure may require additional work. So, we decided to set up what should be done first.
Delving into the project
There were many apprehensions. First of all, the system was built for a particular hardware, and we didn’t know whether it will work properly and fast on virtual machines. Second, it uses third-party tools like biometrics recording, so we couldn’t predict if they will work in the same way in the cloud. Third, Azure works with particular tools and products, that might be incompatible with the system.
Validating the idea
To avoid risks we deployed ASP.NET Webforms application on Azure, our team decided to build development environment in the cloud and validate it with test datasets. It was the only way to recognize all possible issues without violating the production.
In short, the initial system consisted of the MS SQL database, web server where the web portal was hosted through the IIS connection, and the biometric service server.
All these application parts were written to be hosted on-premise, so we had to carefully prepare cloud environment before migration, as well as rewrite some app parts.
We started with acquiring and configuring Azure Virtual Machines (VM) with Visual Studio
Then we copied system’s APIs to VMs, but the biometric matching service didn’t work
We refactored it and switched biometric API to use load balancing
Made a few more modifications to adjust it to Azure environment environment
After, we tested Azure Dev with Azure App Service, and found and resolved even more curious issues we are going to discuss further in this case. But for now, check out how the system looked in Azure for that moment.
AZURE
MS SQL
Portal (Web Hosting) App Service
Azure Load Balancer
VM 1 API
VM 2 API
While building dev environment we figured out existing MS SQL database is not compatible with Azure MS SQL due to exotic stored procs. The thing is Azure cloud uses only UTC time zone, while client’s system used EST, and it caused a total mess in making records Our engineers managed to ASP.NET app to insert to Azure SQL database. They rewrote 140 stored procs in DB and source code of website to use EST time, so the system started making records correctly.
IMPORTANT:
Get to know all the limitations of cloud environment and compare them with your current system. Also, you should compare your system capacity with the tier you acquire in Azure to not slow down the system after the migration.When we moved on to ASP.NET Webforms to Microsoft Azure migration and activated Azure Firewall we found out that it blocks specific type of harmless requests, while their proceeding is a part of the system work. We replaced it with Cloudflare Firewall, that still is not the best match, but it allows needed requests and protect the system from hacking.
After all, test environment started working well, so we moved production to the cloud – the easiest part of the whole process.
You may think this is the end of the story,
but in most cases moving Webforms to Azure is
just a beginning of many improvements
and adjustments both technical and organizational.
The hidden pitfalls
Due to specific business needs, company’s employees track end-to-end data evolving recordings for the last 10 years.
When they have launched the report building on Azure after migration, trying to get the data for the period of 10 yers, it hadn’t proceeded because of Azure time limitation (504 issue).
By the default, Azure waits 120 seconds till the webpage’s response, but what about a 10-year report?
Our team rewrote reports to launch report building as a background process, that could be accessed through the link. However, after the migration of ASP.NET Webform to Azure, the execution time of report building feature was unsatisfactory.
Our engineers refactored report building part and made it 200 times faster. Now you see that code quality matters.
We found out that due to poor coding practices used when the system was created, the system performed spare computing, so virtual machines couldn’t proceed it as fast, as the hardware server did.
REMEMBER
Common cloud services won’t work for heavy computation, as virtual machines capacity is limited. If you work with high workloads choose on-premises.
200 times faster
99,99% guaranteed 
297 code issues While writing this case we were honest about cloud and its specifics, so you may think it’s not worth of migration efforts. Actually, it’s worth.
Continuity is the most crucial thing for client’s system, and it was the main reason for them step in to Webforms to Azure migration.
As for now, system is not dependent on particular employees or unpredictable occasions like power outage.
We also updated all parts of the system and third-party tools versions.
Results
Count all your moves beforehand. You should know your budgets for the migration project as well as for system maintenance in the cloud, tier level to keep performance on the same level. Get to know if all the elements of your current app are compatible with cloud, to not seek a solution in the last moment.
Cloud environment limitations may hit you in unexpected way. Keep in mind things like request size, webpage load speed, and (oh God) time zones. By the way, in Azure HTTP request should be less than 128 kilobytes, page response speed < 120 seconds, and time format is GTM.
We performed many external and internal projects and can say for sure, that every project (product) should have an owner, who will be the main point of decision making and responsibility. You can hire a professional or involve current employee for this role.
This project wasn’t easy. We faced many issues for the first time, but I’m proud that we managed to resolve them all and deliver a qualitative cloud solution. I’m also grateful to our client for this valuable experience and patience in the most critical moments.
Contact our legacy software modernization company to start your successful cloud migration story.
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