Currently trend cache can hold only one entry per item meaning that at the beginning of every hour when item receives the first value for this hour item trend for the previous hour has to be flushed to DB immediately to start accumulating new trend in the cache.

Given that most items have update intervals which are less then 5 minutes such approach to trend caching leads to peak loads for history syncers and DB backend in first five minutes of an hour. This slows down overall Zabbix data flow and introduces latency in problem detection and escalation.

To counter this effect trend cache should be redesigned to be able to store more than one trend per item and flush trends of past hours without a rush.