check_afs_rpc is a Nagios plugin for checking AFS file servers to see if there are client connections waiting for a free thread. If there are more than a few of these, AFS performance tends to be very slow; this is a fairly reliable way to catch overloaded file servers. By default, check_rxdebug returns a critical error if there are more than eight connections waiting for a free thread, and a warning if there are more than two. These thresholds can be changed with the --critical and --warning options. check_afs_rpc will always print out a single line of output including the number of blocked connections, and displaying whether this is critical, a warning, or okay.
EMS is an event manager for PIKT and other monitoring tools that allows you to send UDP events instead of mail messages from PIKT alarms (not alerts). Those events are sent as XML ciphered (you can use your favorite cipher) messages via UDP, from the client (epush) to the manager (eventd), consolidate events together (grouping events together or discarding them when necessary), and store events in a backend database. The database is your choice, although EMS has been developed with MySQL in mind. Hooks are in place to provide future advanced event correlation, "management" of events via a web interface, display alerts on user uploaded maps, and send data from your performance monitoring application to RRDTool via special 'data' events.
innotop is a MySQL and InnoDB monitor that lets you view and manage what's happening inside your MySQL servers. Features include a top-like query list, a top-like InnoDB transaction list, and much more. This tool gives you a high level of insight into the inner workings of InnoDB.