Zabbix 2.2, distributed monitoring, nodes. After update from 2.0, event syncronization ( from slave nodes to master node ) is completely broken.
Other data ( history_log, history_str_sync, history_uint_sync, history_sync ) synchronization works fine.

As a result, there are obsoleted data on master node. Triggers are actual, mail notification send in time, but monitoring->dashboard show obsoleted information and monitoring->events show obsoleted information. So, multinode configuration become garbage.

In traffic dump i can see that

1. zabbix master return constant value for all requests "ZBX_GET_HISTORY_LAST_ID.202.202 events.eventid"
2. nevertheless, zabbix server response "OK" for every synchronization request "History.202.202.events" with ~ 5k events.

I rebuild zabbix from source on master node with debug messages ( src/zabbix_server/events.c, zabbix_log(LOG_LEVEL_WARNING,"events num: %i", events_num); ) . After that, i see that events successfully add to an array ( add_event() ), and events_num increase every sync. But in process_events() debug message every time show "events_num: 0" , su events does not push to database

I create test stand ( 2 node, clear install zabbix 2.2 and mysql 5.6 ). It show the same problem. I.e. it's not an upgrade issue, but zabbix branch 2.2 bug