Zabbix data loosing after 6.0 upgrade to 7.0

[gertz]

Hello, I want ask for help because Im going crazy. after upgrade from 6.0 to 7.0 my zabbix agents loosing connections. I tried almost everything like conf below. it was better than default but still lossing data. I have 30 host with passive agents and 2700 items.

I know there was some asynchronus changes, but I dont know what else do.

Thanks for any help

LogFile=/var/log/zabbix/zabbix_server.log
LogFileSize=0
PidFile=/run/zabbix/zabbix_server.pid
SocketDir=/run/zabbix
DBName=zabbix
DBUser=xxxxxxxx
DBPassword=xxxxxxxxx
StartPollers=20
StartAgentPollers=30
StartHTTPAgentPollers=4
StartSNMPPollers=4
MaxConcurrentChecksPerPoller=5
StartPreprocessors=16
StartPollersUnreachable=10
StartPingers=10
StartHTTPPollers=5
SNMPTrapperFile=/var/log/snmptrap/snmptrap.log
Timeout=10
FpingLocation=/usr/bin/fping
Fping6Location=/usr/bin/fping6
LogSlowQueries=3000
StatsAllowedIP=127.0.0.1
EnableGlobalScripts=0
Include=/etc/zabbix/zabbix_server.d/*.conf

logs:

173293:20261024:083042.183 Zabbix agent item "vfs.fs.size[/mnt/nextcloud/data,pfree]" on host "host-1" failed: first network error, wait for 15 seconds
173293:20261024:083042.183 Zabbix agent item "system.cpu.util[,interrupt]" on host "host-2" failed: first network error, wait for 15 seconds
173332:20261024:083042.186 Zabbix agent item "proc.num[]" on host "question-api" failed: first network error, wait for 15 seconds
173332:20261024:083042.186 Zabbix agent item "vm.memory.size[free]" on host "host-3" failed: first network error, wait for 15 seconds
173336:20261024:083042.186 Zabbix agent item "vfs.fs.size[/data,pused]" on host "host-4" failed: first network error, wait for 15 seconds
173293:20261024:083057.165 resuming Zabbix agent checks on host "host-3": connection restored
173303:20261024:083057.165 resuming Zabbix agent checks on host "host-2": connection restored
173290:20261024:083057.167 resuming Zabbix agent checks on host "host-4": connection restored
173293:20261024:083057.188 resuming Zabbix agent checks on host "host-5": connection restored
173303:20261024:083057.223 resuming Zabbix agent checks on host "host-1": connection restored

[gertz]

After digging and searching in debug logs I got only one result "Timeout while contacting DNS servers" zabbix 7.0 resolving every passive check separately and its causing too many request to DNS. So If dns server have limit for host it will cause this issue. I did some changes and will monitor that.

[gertz]

After digging and searching in debug logs I got only one result "Timeout while contacting DNS servers" zabbix 7.0 resolving every passive check separately and its causing too many request to DNS. So If dns server have limit for host it will cause this issue. I did some changes and will monitor that.