The "-detached" flag of my ns_job example is for demo purposes, causing asynchronous behavior (many things are added to the queue, the jobs are executed one-by-one in the background). When ns_job is called without this flag, then the caller will wait for the result (or until the configurable timeout is reached).
... with "ns_job" one can run arbitrary commands, also including arbitrary db-operations or "exec"... so there is much flexibility. One possible feature missing in ns_job is persistency on server restarts, but that might or might not be an issue for some applications. For persistency, there is the option of xowf's at-commands or rolling your own db-based command queue, similar to acs-mail-lite.
