Structural and semantic deficiencies in the systemd architecture for real-world service management
This is a in-depth architectural critique of systemd. It claims to be the first purely technical review of systemd internals, and provides a detailed analysis of several components. It criticizes on the basis of ordering related failures, a difficult to predict execution model, non-determinism in boot-order, as well as several other points.
Though many users would perceive the long processing pipeline to increase reliability and be more "correct" than the simpler case, there is little to acknowledge this. For one thing, none of jobs, transactions, unit semantics or systemd-style dependencies map to the Unix process model, but rather are necessary complications to address issues in systemd being structured as an encapsulating object system for resources and processes (as opposed to a more well-defined process supervisor) and one accommodating for massive parallelism. Reliability gains would be difficult to measure, and that more primal toolkits like those of the daemontools family have been used in large-scale deployments for years would serve as a counterexample needing overview.
(Score: 2) by sjames on Monday October 19 2015, @06:51AM
Some of the daemons I write have NO scripting other than for convention. You can directly link the executable into rc?.d if you like. Too bad systemd can't handle that.
In other cases, my script is just a few lines, one for each of start, stop, status, and reload (sometimes not even status and reload). It doesn't get much simpler.
It's really up to you how simple or complicated you want to make it.