Modern applications often require different operational tasks to maintain them. As monolithic applications are broken down into multiple components, how the application needs to be maintained has changed.
Consider the following operational tasks on a modernized application that doesn’t consist of a virtual machine.
Recoverability - If an application is made up of a set of disposable microservices, there shouldn’t be state data within services, so they don’t require backups. However, the backing services for a monolith might’ve been a single source, meaning a single item to backup. In a distributed system, multiple backing services may need to be protected from failure, and subsequently, more backup routines are needed.
Deployment - Monolithic applications result in a virtual machine being provisioned. Microservices may require for many services to be deployed. If your corporate deployment process involves opening and closing tickets to deploy a service, the number of tickets being created will dramatically increase. A continuous deployment methodology may be a better fit for a modern application architecture.
Observability - Within a virtual machine, it is common to have an agent installed to gather performance metrics or logs. With microservices-based architectures, logs are distributed, meaning that to correlate logs between services, you must first aggregate them. Performance metrics in a container-based solution are often published by the application and scraped by a solution such as Prometheus.
Security Updates - Virtual machines running a monolith are often left in place for long periods and patched regularly to mitigate vulnerabilities. Container-based workloads aren’t patched in place but are rebuilt and redeployed with a fresh image. Be prepared to rebuild microservices as part of a regular security mitigation process.
Network Security - In a simple two-tiered application between a virtual machine and a database, there is one network path to secure. When using microservices, there may be many network paths to secure. A service mesh solution such as Tanzu Service Mesh might be used to secure these connections with mutual transport layer security (mTLS).
