zabbix_get could not get data from some hosts

[robertchen]

hi all,

both server and agent are running on default ListenIP without configured, 0.0.0.0 .
tcp 0 0 0.0.0.0:10050 0.0.0.0:* LISTEN

both server to client ways 10050, 10051 are open. telnet on both ways ok:

[root@zbx01 ~]# telnet host33 10050
Trying 10.1.50.16...
Connected to host33.
Escape character is '^]'.

both hosts 10050 are listening but:
[root@zbx01 ~]# zabbix_get -s host33 -k "net.tcp.port[,10050]"
0

[root@zbx01 ~]# zabbix_get -s host1 -k "net.tcp.port[,10050]"
1

host33 is not returning data, host1 is ok.

after enable debug, I found these:

9799:20140710:235859.233 Requested [net.tcp.port[,10050]]
9799:20140710:235859.233 TCP expect network error: cannot connect to [[127.0.0.1]:10050]: [13] Permission denied
9799:20140710:235859.233 Sending back [0]

how to resolve this?

Please help, it is urgent, thanks.

[robertchen]

I enable debug on the agent, the output is from the agent. some metrics could be return, some like net.tcp.port and proc.num cannot:

[root@zbx01 ~]# zabbix_get -s host33 -k "net.tcp.port[,10050]"
0

[root@zbx01 ~]# zabbix_get -s host33 -k "system.cpu.util[,iowait]"
0.368201

on the host33
[root@host33 zabbix]# zabbix_agent -t net.tcp.port[,10050]
net.tcp.port[,10050] [u|1]

[aib]

Are you sure that SElinux is not installed on host33?

[robertchen]

Are you sure that SElinux is not installed on host33?

if it is disable, I am able to get the data. what is SELinux?

[aib]

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Security-Enhanced_Linux/