Ganglia gmond gmetad Important Configuration & Commands

1)ganglia gmond and gmetad it will communicate via multicast IP.

So we have to configure multicast IP as route in eth0 (also private IP also should configure in eth0)

/sbin/route add -host 239.2.11.71 dev eth0

Note:1)Multicast IP Range From 224.0.0.0 To 239.255.255.255.

2)Configuration (/etc/gmond.conf)

udp_recv_channel {

mcast_join = 239.2.11.71

port = 8649

bind = 239.2.11.71

}

3)Verification method.

# netstat -tulpn | grep gmond

tcp 0 0 0.0.0.0:8649 0.0.0.0:* LISTEN 4946/gmond

udp 0 0 239.2.11.71:8649 0.0.0.0:* 4946/gmond

Useful command.

1)# gstat -d 5

CLUSTER INFORMATION

Name: HCL Cluster

Hosts: 1 [ No Of the Hosts are interacting]

Gexec Hosts: 0

Dead Hosts: 0

Localtime: Mon Feb 4 16:48:33 2013

DEAD CLUSTER HOSTS

There are no hosts down at this time

2)# gmond -f -d 10 [ -f run in foreground -d for debug level 10 ]

loaded module: core_metrics

loaded module: cpu_module

loaded module: disk_module

loaded module: load_module

loaded module: mem_module

loaded module: net_module

loaded module: proc_module

loaded module: sys_module

loaded module: multicpu_module

loaded module: python_module

Discovered device /

Discovered device /opt

Discovered device /boot

udp_recv_channel mcast_join=239.2.11.71 mcast_if=NULL port=8649 bind=239.2.11.71

tcp_accept_channel bind=NULL port=8649

Unable to create tcp_accept_channel. Exiting.

3)Ganglia Communication.

[root@master ~]# netstat -tulp | egrep 'gmond|gmetad'
tcp        0      0 *:8649                      *:*                         LISTEN      5667/gmond         
tcp        0      0 *:8651                      *:*                         LISTEN      5677/gmetad        
tcp        0      0 *:8652                      *:*                         LISTEN      5677/gmetad        
udp        0      0 239.2.11.71:8649            *:*                                     5667/gmond    
[root@node3 ~]# netstat -tulpn | grep gmond
tcp        0      0 0.0.0.0:8649                0.0.0.0:*                   LISTEN      4946/gmond         
udp        0      0 239.2.11.71:8649            0.0.0.0:*                               4946/gmond 

Common Error Message

ERROR 1: If we are not properly configured the multicast IP as router then we will get the following error message.

1)/var/log/message

Feb 1 17:07:45 master /usr/sbin/gmond[11378]: Unable to create UDP client for master@hcl.com:8649. Exiting.

Feb 1 17:07:46 master /usr/sbin/gmetad[11333]: data_thread() got no answer from any [IIT_GUWAHATI] datasource

Above error we were getting due to no communication between gmond and gmetad on sameserve

Error 2: # /etc/init.d/gmond status

gmond dead but subsys locked

Solution: configure mulitcast IP as router.

Note : In the master Node. We should configure.

Eth0 as the private IP(10.0.0.0)

Eth1 should configure as Public IP(192.168.0.0) to maintain the proper communication between the nodes and master.