The weirdest thing happened today, We have have recently created new servers, and I wanted to add them to the our Zabbix monitoring service, so I tried to clone an existing host, and it got stuck and the error was "Unexpected server error.".

I tried creating a new host, same error; Tried creating a simple host with no templates and no interfaces, same error; Tried creating in disabled mode, same error; Tried editing current hosts, same error; Even tried deleting and existing host, same error.

The weirdest thing is among 100 tries, 4 or 5 times the task was done successfully; and when I try to re do it, I get the same error.

There is no related log entries in /var/log/zabbix/zabbix_server.log or /var/log/postgresql/postgresql-14-main.log. But there is one nginx logs keeps reappearing:

2023/05/24 13:02:49 [error] 705566#705566: *4115 FastCGI sent in stderr: "PHP message: PHP Deprecated:  Parameter "/auth" is deprecated. in /usr/share/zabbix/include/classes/validators/CApiInputValidator.php on line 1475" while reading response header from upstream, client: 127.0.0.1, server: zabbix.example.com, request: "POST /api_jsonrpc.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/zabbix.sock:", host: "localhost:8080"

And two logs which appear from time to time: (192.168.0.0 is my client's IP Address)

2023/05/24 12:47:34 [error] 705566#705566: *3131 upstream timed out (110: Unknown error) while reading response header from upstream, client: 192.168.0.0, server: zabbix.example.com, request: "POST /zabbix.php?action=host.create HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/zabbix.sock", host: "zabbix.example.local:8080", referrer: "http://zabbix.example.local:8080/zabbix.php?action=host.edit&groupids%5B0%5D=23"

2023/05/24 13:01:49 [error] 705566#705566: *3998 FastCGI sent in stderr: "PHP message: PHP Deprecated:  Parameter "/auth" is deprecated. in /usr/share/zabbix/include/classes/validators/CApiInputValidator.php on line 1475PHP message: PHP Deprecated:  Parameter "/real_hosts" is deprecated. in /usr/share/zabbix/include/classes/validators/CApiInputValidator.php on line 1475" while reading response header from upstream, client: 127.0.0.1, server: zabbix.example.com, request: "POST /api_jsonrpc.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/zabbix.sock:", host: "localhost:8080"

I've tried restarting services, rebooting the server. changing browsers, users etc, none helped.