JMX error, ZBX_TCP_READ() timed out

[jcma]

Hi,
I am a new zabbix user and I have encountered a problem that I cannot solve. I add some images to ilustrate problen
I am using the official images (https://github.com/zabbix/zabbix-docker), I use docker-compose with Ubuntu and MySql (4.4.5).

**UPDATE: the error in zabbix-java-gateway container is:
zabbix-java-gateway_1 | 2020-03-30 08:18:08.004 [pool-1-thread-4] WARN com.zabbix.gateway.SocketProcessor - error processing request, item "jmx["kafka.server:type=BrokerTopicMetrics,name=Mes sage sInPerSec",FifteenMinuteRate]" failed: Connection timed out: service:jmx:rmi:///jndi/rmi://devxxcas002.xxxx.local:12345/jmxrmi

In the web interface I configure a host with JMX connection:



I configure the cassandra service as indicated in https://www.zabbix.com/documentation...jmx_monitoring (without authentication and responding from outside)
I check that I can access the configured port from another machine (there are no connection problems to the used port):



I check that zabbix-java-gateway listens on port 10052 and that it is accessible from zabbix-server:


Can someone guide me to know where I am going wrong?
Thank in advanced

[jcma]

Hi, I answer myself.
The problem, or at least it worked for me, is that in the docker-compose configuration I use (ubuntu with mysql) the network part for zabbix-java-gateway needs to include the network "zbx_net_frontend".

Can anyone tell me if this is correct and should I request to update the docker-compose * .yaml files in the GIT repository?

I attach the zabbix-java-gateway configuration:

[INDENT][COLOR=#000080][I]zabbix-java-gateway:
  image: zabbix/zabbix-java-gateway:ubuntu-4.4-latest
  ports:
   - "10052:10052"
  deploy:
   resources:
    limits:
      cpus: '0.5'
      memory: 512M
    reservations:
      cpus: '0.25'
      memory: 256M
  env_file:
   - .env_java
  user: root
  networks:[/I][/COLOR]
[COLOR=#000080][I]zbx_net_backend:[/I][/COLOR]
[COLOR=#000080][I]  aliases:
     - zabbix-java-gateway
     - zabbix-java-gateway-ubuntu[/I][/COLOR]
[B][COLOR=#B22222]zbx_net_frontend:[/COLOR][/B]
[COLOR=#000080][I] stop_grace_period: 5s
  labels:
   com.zabbix.description: "Zabbix Java Gateway"
   com.zabbix.company: "Zabbix SIA"
   com.zabbix.component: "java-gateway"
   com.zabbix.os: "ubuntu"[/I][/COLOR][/INDENT]