How to solve [Zabbix agent is not available (for 3m). 】

[Matsunaga]

I am a Japanese user, my English is not very good, please understand. I am using Zabbix5.0 to monitor more than 80 servers. But since two weeks ago, there are two hosts (WindowsServer2008), always receive the following warning. [Zabbix agent is not available (for 3m). 】 But after 1 to 2 minutes it will be resolved again. All other servers are fine. It's never happened before, and I haven't changed any settings recently. I don't know how to solve this problem, please help me.

[Michał Czerniakiewicz]

Hello Matsunaga,
Please check the triggers of your action for these hosts. It appears like warning condition has been triggered then next condition to autoresolve. Does it started happening after changes on the Zabbix server or these two hosts? How often do you receive the warnings?
Kind regards

[Matsunaga]

addition:
The ZBX icon turns red and the following message is displayed.
　Get value from agent failed: cannot connect to [[***.***.***.***]:10050]: [4] Interrupted system call
But after a few minutes it turns green again.

[Matsunaga]

addition:

I checked Zabbix Agent log, it shows like below

 3116:20230303:081642.495 active check configuration update from [***.***.***:***:10051] started to fail (cannot connect to [[***.***.***:***]:10051]: [0x00002740] Usually every socket (protocol, network address or interface) can use onetime.
3116:20230303:081742.497 active check configuration update from [***.***.***:***:10051] is working again
  3116:20230303:101945.882 active check configuration update from [***.***.***:***:10051] started to fail (cannot connect to [[***.***.***:***]:10051]: [0x00002740] Usually every socket (protocol, network address or interface) can use onetime.
  3116:20230303:102045.884 active check configuration update from [***.***.***:***:10051] is working again

[Matsunaga]

addition:
trigger
{hostname:zabbix[host,agent,available].max({$AGENT.TIMEOUT})}=0
AGENT.TIMEOUT is 3m

[clynksanael]

I am also currently encountering this error and is also showing the "Get value from agent failed: cannot connect to [[***.***.***.***]:10050]: [4] Interrupted system call" error message.