Collector Node Sanity Checks

This is an informational KB article that an opsview user must be weary about;

• NOTE: In order to avoid split-brain issues within a cluster, have an odd amount of hosts within a cluster for example 1, 3, 5, etc. rather than an even number of hosts.

The below commands can be run on your master/collector to derive node status information pertaining to its cluster.

Messagequeue**:**

Cluster Status information received from rabbitmqctl cluster_status

As you see below the opsview collector “opsviewcol03” is part of a 3 host collector cluster, while running the rabbitmqctl cluster_status

root@opsviewcol03:~# /opt/opsview/messagequeue/sbin/rabbitmqctl cluster_status
Cluster status of node rabbit@opsviewcol03.opsview.com ...
Basics

Cluster name: opsviewcol03

Disk Nodes

rabbit@opsviewcol01.opsview.com
rabbit@opsviewcol02.opsview.com
rabbit@opsviewcol03.opsview.com

Running Nodes

rabbit@opsviewcol01.opsview.com
rabbit@opsviewcol02.opsview.com
rabbit@opsviewcol03.opsview.com

Versions

rabbit@opsviewcol01.opsview.com: RabbitMQ 3.8.9 on Erlang 22.3
rabbit@opsviewcol02.opsview.com: RabbitMQ 3.8.9 on Erlang 22.3
rabbit@opsviewcol03.opsview.com: RabbitMQ 3.8.9 on Erlang 22.3

The above is true as it’s part of a 3-host RabbitMQ cluster node and only shows you the hosts within that cluster.

Datastore:

The same practicality lies within the datastore, you will need to check the membership list within CouchDB,

• Prerequisite to the below is installing support scripts

root@opsviewcol03:~# /opt/opsview/supportscripts/bin/datastore membership
{
"all_nodes" : [
"couchdb@opsviewcol01.opsview.com",
"couchdb@opsviewcol02.opsview.com",
"couchdb@opsviewcol03.opsview.com"
],
"cluster_nodes" : [
"couchdb@opsviewcol01.opsview.com",
"couchdb@opsviewcol02.opsview.com",
"couchdb@opsviewcol03.opsview.com"
]
}

The above is also true as it’s part of a 3-host CouchDB cluster node and only shows you the hosts within that cluster.