runtimeadjustable

Runtime adjustable refers to systems, components, or parameters that can be changed while the system is running, without a restart. This capability enables operators and automated systems to modify behavior, performance, or resource usage on the fly. It applies across software applications, services, embedded devices, networking equipment, and industrial controllers.

Common mechanisms include dynamic configuration stores (etcd, Consul, or built-in config services), management APIs, and user interfaces that adjust settings such as log levels, thresholds, feature toggles, routing rules, and resource limits. Techniques include hot-swapping modules, dynamic reconfiguration of services, and the use of parameter servers or feature flags. Examples: increasing max concurrent connections, enabling a new feature flag for gradual rollout, changing a cache size, adjusting alert thresholds.

Benefits include reduced downtime, faster tuning, and the possibility of automated self-tuning. Risks include inconsistency, race conditions, security concerns, misconfiguration, and potential safety issues in critical systems. Best practices: validate changes in a staging or dry-run mode, support atomic or transactional updates, log and audit changes, provide rollback, enforce access control, and document versioned configurations.