The notion of category is extensive in OpenNMS and is subdivided into several contexts.
SLM / RTC Categories
These categories are used for grouping interfaces and services for purposes of Service Level Management (SLM). Availability is maintained separately per category and is represented as a percentage of time during which the category's member services were available during a configurable sliding window in time. By default this window is 24 hours in length. The SLM availability numbers are most commonly displayed in the real-time console (RTC) on the front page of the web UI, but are also used in the creation of historical availability reports. SLM categories are maintained by the RTC daemon or RTCd.
SLM categories are declared in the file etc/categories.xml and referenced in the file etc/viewsdisplay.xml.
For details on surveillance categories, see the OpenNMS user guide.
This kind of category is defined as part of a node's asset data. There are 5 asset categories as of this writing:
- Category (keyworkd category)
- Display category (keyword displayCategory)
- Notification category (keyword notifyCategory)
- Polling category (keyword pollerCategory)
- Threshold category (keyword thresholdCategory)
Like surveillance categories, asset categories may be used in Filters and Rules. Their use is not restricted to the set of uses implied by their respective names.