Zabbix

.......PS. [ZBXNEXT-6144] added proxy data memory cache to avoid using proxy history tables in normal operation

Merge in ZBX/zabbix from feature/ZBXNEXT-6144-6.5 to master

* commit '05c90e303cf57a1b64aa83eabba3ae6542bad0c2': (75 commits)
  ..F....... [ZBXNEXT-6144] added helper items
  .......P.. [ZBXNEXT-6144] added proxy memory buffer to zabbix.stats
  .......P.. [ZBXNEXT-6144] style fix
  .......P.. [ZBXNEXT-6144] fixed buffer freeing in memory mode
  .......P.. [ZBXNEXT-6144] fixed uninitialized variable usage when freeing no-value history rows read from db
  .......... [ZBXNEXT-6144] updated default proxy configuration file
  .......... [ZBXNEXT-6144] added upgrade patch
  ...G...... [ZBXNEXT-6144] fixed merge
  .......P.. [ZBXNEXT-6144] fixed waiting for history rows in database during gap detection
  .......P.. [ZBXNEXT-6144] fixed check for autoreg memory rows when flushing proxy buffer
  .......P.. [ZBXNEXT-6144] uppdate lastid_db in cache when flushing memory buffer
  .......P.. [ZBXNEXT-6144] fixed database flushing and state switching
  .......P.. [ZBXNEXT-6144] fixed warnings
  .......P.. [ZBXNEXT-6144] changed proxy buffer readers to update its state only after some row upload
  .......P.. [ZBXNEXT-6144] fixed buffer state switching in hybrid mode
  .......P.. [ZBXNEXT-6144] changed proxy history gap handling from single retry to waiting for currently open handles to be closed
  .......P.. [ZBXNEXT-6144] moved proxy buffer history id assignmenent inside lock
  .......P.. [ZBXNEXT-6144] added proxy buffer diaginfo
  .......P.. [ZBXNEXT-6144] fixed warning
  .......P.. [ZBXNEXT-6144] allocate proxy buffer in disk mode to store statistics, added proxy buffer destroying
  ...