Who said that grepping Apache logs has to be boring?
The truth is that, as Enteprise applications move to the browser too, Apache access logs are a gold mine, it does not matter what your role is: developer, support or sysadmin.
If you are not mining them you are most likely missing out a ton of information and, probably, making the wrong decisions. ELK (Elasticsearch, Logstash, Kibana) is a terrific, Open Source stack for visually analyzing Apache (or nginx) logs (but also any other timestamped data).
The ZFS filesystem has many features that once you try them you can never go back. One of the lesser known is probably the support for replicating a zfs filesystem by sending the changes over the network with zfs send/receive.
Technically the filesystem changes don't even need to be sent over a network: you could as well dump them on a removable disk, then receive from the same removable disk.
Everyone knows that OpenNMS is a powerful monitoring solution, but not everyone knows that since version 1.10 circa it embeds the Drools rule processing engine. Drools programs can then be used to extend the event handling logic in new and powerful ways.
The following example shows how OpenNMS can be extended to detect missed executions for recurring activities like backups or scheduled jobs.