Microservices refer to the thousands of independent web standards, programming languages, database platforms, and web server components that are found in the contemporary software development lifecycle as developer tools. From a traditional perspective, enterprise companies once focused on Service-Oriented Architecture (SOA) which represented hardware and software technology that was integrated from a single IT company. With microservices, there are thousands of different components being supported in cloud software applications and web servers from independent development companies or open source communities. IT departments needed a new philosophy to manage microservices in production across isolated multi-tenant environments in hyper-scale public cloud data centers and have widely adopted virtualization solutions with SDDC standards driven by service mesh technology to solve this. Microservices form the building blocks or fundamental components, platforms, and frameworks on which code is built and operated on web servers in a cloud data center.
Microservices work primarily by increasing the functionality available on a web server over that which is provided by the default operating system, network, or data center management platform. Some microservices are web server stack extensions like programming language platforms and database frameworks. In order to develop PHP and MySQL applications, the web server environment must be configured with LAMP platform support. Microservice-based solutions compete largely with the Service-Oriented Architecture supplied by Microsoft, Oracle, IBM, and other IT majors in closed-source distributions. Enterprise companies must now support multiple applications written in PHP, Python, Ruby-on-Rails, Java, C++, ASP.net, etc. in tandem or simultaneously in production. In other situations, a data center may have multiple databases frameworks in operation via VMs on multi-tenant hardware. A web server must be configured for support of custom extensions for streaming media, API integrations, or through adding proprietary utilities for analytics. Whenever all these third-party and open source services are added together, they equal thousands of microservices on a typical web server in production, which are then multiplied by millions of VMs at hyper-scale in a public cloud service environment.
The use of microservices as a term primarily developed after the Web 2.0 era as corporate IT needed a new way to conceptualize the software development environment to reflect the current ecosystem and best practices. The use of microservices for the development of web and mobile applications has led to increased complexity for data center administrators to support in enterprise operations. Instead of simply contracting with Oracle, IBM, or Microsoft for all required software and data center solutions, companies now must navigate a landscape with millions of open source code projects which offer enterprise-grade solutions for business use. Many web standards have competing versions from different companies. Many programming languages and databases cover the same functionality in use. Each development team has their own preferences for tools and programming methods. Managing all of this complexity in the cloud era within a unified corporate IT department has led to the need to support microservices in professional software development in many complex organizations worldwide.
The best way to understand microservice architecture is to picture the layers of software in a web server stack. The operating system can be either Windows, Linux, or BSD for the web server. There are tools for data center management and load balancing on the network. There is a choice of Apache, IIS, NGINX, Caddy, Tomcat, etc. for the web server. Next is the layer for the installed programming language support, such as PHP, ASP.net, Python, Ruby, Perl, Java, and Go. Following is the layer for database frameworks like MySQL, MSSQL, PostgreSQL, and MongoDB. Another layer for caching utilities like Varnish, Redis, CDNs, and optimization utilities. Other layers of support include edge servers, serverless platforms, and AI/ML integration. Within a public cloud ecosystem, there are thousands of microservices operating simultaneously which need to be managed in the service mesh to support interoperability, routing, and communications.
Service-Oriented Architecture (SOA) usually comes from a single vendor or includes a package of hardware and software solutions that can be deployed for a well-defined industry need. SOA supports the data center, the web server, and the stack layer through different distributions or product models. SOA is available in both proprietary and open source solutions by vendor. Networking equipment and fiber connections are managed in different ways in cloud data centers vs. in-house private data centers. Microservices are required for innovation in the current state of the software development landscape. Even the largest corporations need to adopt microservices in support of Agile programming teams bringing new web/mobile applications to market, where product support can include thousands of brands or domains. Microservices are frequently required for the modernization and containerization of legacy enterprise software.