Value cache memory efficiency improved - now it requires less shared memory to cache the same amount of values.
Improved error logging for server-proxy communication. A number of error messages in server and proxy log files have been improved to provide more information about failures.
Zabbix application names in syslog fixed to meet RFC 5424 for APP-NAME. See Syslog application names change
A trigger can now only be processed by one main, history syncer or timer process at a time, which should eliminate problems like multiple successive OK events and might lead to a performance improvement for timer processes on large systems, because they will not do duplicate work by processing triggers already being processed by history syncers.
Trigger processing performance during low level discovery has been improved.
Low level discovered triggers won't be deleted and will still work if relevant items are not discovered anymore (until those items get deleted).
Synchronized ICMP ping check (icmpping, icmppingloss and icmppingsec) scheduling for items with the same interface. Before if a host had multiple ICMP ping based items it was highly possible that the fping utility will be invoked for every item. Synchronizing ICMP ping checks allows to invoke fping utility only once for all checks (given that all of those checks have the same packet count, interval, size and timeout values). For instance, if a host has icmpping, icmppingloss and icmppingsec items, then only 3 packets will be sent in one fping invocation, whereas before it would likely send 9 packets in three fping invocations.
Previously, when ITEM.LOG.* macros were substituted in notifications, item configuration information was obtained from the database. Since Zabbix 2.2.2 this information is obtained from the configuration cache.
HOST.PORT macro is now supported in internal and trigger-based notifications, as well as in trigger names and descriptions. It now supports an optional number suffix to reference hosts in the order in which they appear in a trigger expression ({HOST.PORT1}, {HOST.PORT2} ...).