This morning, effectively as I slept, my Linux computer named ‘Phoenix’ downloaded and installed a set of updates, to KDE, which is the framework installed on this computer, for managing the display of my Desktop / GUI, as well as for PIM. Because this update installed itself unattended, it meant that user-processes were still running, which did not have the latest version of the software loaded into RAM.
This can happen easily on Linux computer-systems, which generally just keep working that way – in the short term. But in the long term, eventually something is going to want to wake up a KDE-program which is not already running, and which will want to use the latest images, at which point some sort of incompatibility could set in.
Fortunately though, KDE will only affect user-processes, as I just wrote, but will not affect system-processes, such as my Apache Web-server, or the instance of the MySQL-server, which is running as a system- rather than as a user-process. And so what I can do in this case, is just log out the user, and log him back in. Doing so also reloads the X-server, which does a shutdown as well, and restarts the graphics-driver.
Both the update to KDE, as well as my log-out, log-in maneuver, worked well, without any hint at first glance, of anything going wrong. As a result, the availability of the site and my blog were unaffected. Also, the ‘
memcached‘ process is a system-process that did not require any restart, so that the responsiveness of my blog, to the most-frequent requests for postings from readers, should still be as quick as it was only 30 minutes ago.