Steps to reproduce:

1. Completed LLD configuration

Name - Barman backed servers discovery streaming

Type - Zabbix agent

Key - monitoring.barman.discovery.streaming

Host interface - 127.0.0.1:10050

Update interval 300

2. Zabbig agent has the following configuration:

UserParameter=monitoring.barman.discovery.streaming, /bin/echo -ne '\{"data":['; for servers in $(/usr/bin/cat /var/lib/barman/list-server.txt | grep "Streaming" | cut -d " " -f 1); do /bin/echo -n "{\"{#BACKED_SERVERS_STREAM}\": \"$servers\"},"; done |sed -e 's:,$::'; /bin/echo -ne ']}'

3. Star Zabbix server

4. Start Zabbixa agents

Result:
Agent logs: - agent.log

Server crash: - стэк.pdf

server config,

agent config
DB - postgres 13