In this blog we will talk about introduction to Azure DevOps Sever earlier called as Team Foundation Server (TFS) and Azure DevOps Services earlier called as Visual Studio Team Services (VSTS). We will learn what is Azure DevOps Server (TFS) and Azure DevOps Services (VSTS), the basic Architecture of Azure DevOps Server (TFS) and different ways that the server can be deployed using various Deployment Topologies of Azure DevOps Server (TFS).

Azure DevOps is DevOps platform/tool for teams to plan work, collaborate on code development, and build and deploy applications.

• Azure Boards
• Azure Repos
• Azure Pipelines
• Azure Artifacts
• Azure Test Plans

Azure DevOps Server: An on-premises offering built on a SQL Server back end. When we want the data to stay within our company network, or when we want access to SQL Server reporting services that integrate with Azure DevOps Server data and tools.

Azure DevOps Services: A cloud offering (SaaS)provides a scalable, reliable, and globally available hosted service. It's backed by a 99.9% SLA, monitored by our 24/7 operations team, and available in local data centers around the world.

Now let us discuss about various possibilities of installing Azure DevOps Server (TFS). Deployment topologies are chosen based on number of users, usage, volume of data and projects, availability, geographically distributed team, and other factors.

Single Server Installation: This is simple installation options and suitable for a smaller number of users, data, and usage. We will have Data tier and App tier installed in single server.

Dual Server Installation: This installation option is required to handle more load than a single server configuration. we will separate out the Data tier and App tier. Also, when we want more power to Data tier to process lot of data we can go for dual server.

Multiple Servers Installation (Complex Topology): We will go for complex topology or multi server installation, when we have huge number of users & data, TFS used by entire organization/business unit, or very critical projects managed in TFS etc. In complex topology, the Azure DevOps Server databases will be hosted on SQL Server Cluster, multiple App Tier with NLB will be configured to sustain more load, TFS Build Farm will consist of Agents installed on multiple servers to cater to the large number of build & release pipeline execution. Collection DBs can be hosted on multiple SQL Cluster instances. The SQL reporting and Analysis databases will be hosted on another Server. Basically, configured for high availability, large data processing, fault tolerance etc.