Item scheduling

Earlier, we discussed what introduces delay before a new item is checked—the Zabbix server configuration cache was mentioned. For passive items, there is another factor involved as well, and it is the way Zabbix schedules items to be polled. Each item is scheduled to be polled at a certain time, and the time between two polls is always constant. Even more, a specific item is always scheduled the same way, no matter when the Zabbix server was started. For example, if an item has a 60-second interval, it could be configured to be polled at second 13 of every minute. If the Zabbix server is restarted, this item will still be polled at second 13 of every minute. This scheduling is based on an internal item ID; hence, a specific item will not get this timing changed during its lifetime unless it is deleted and recreated or the item interval is changed.