Collectd monitoring shows +4 connections more than AMC


#1

I am using the collectd aerospike plugin to report metric like client_connections.

When I have two clients connected to a single node aerospike cluster, I see AMC reporting 3 client connections.

When I run netstat -pant | grep asd, then I see something like:

tcp        0      0 0.0.0.0:3001                0.0.0.0:*                   LISTEN      9874/asd
tcp        0      0 0.0.0.0:3002                0.0.0.0:*                   LISTEN      9874/asd
tcp        0      0 0.0.0.0:3003                0.0.0.0:*                   LISTEN      9874/asd
tcp        0      0 0.0.0.0:3000                0.0.0.0:*                   LISTEN      9874/asd
tcp        0      0 10.1.115.2:3000             10.1.176.51:51833           ESTABLISHED 9874/asd
tcp        0      0 10.1.115.2:59384            10.1.115.2:3002             ESTABLISHED 9874/asd
tcp        0      0 10.1.115.2:3002             10.1.115.2:59384            ESTABLISHED 9874/asd
tcp        0      0 10.1.115.2:3000             10.1.176.51:51836           ESTABLISHED 9874/asd

I assume the three connections are the two clients + 1 connection of the aerospike node to itself on port 3002.

However, the collectd plugin reports 7 connections. Are the +4 connections reported by collectd the 4 LISTEN connections?

I notice the collectd plugin is using the aerospike python client to gather statistics. I also notice that the AMC console is using a citrusleaf python client to communicate with the Aerospike cluster. I suspect there is some inconsistent behavior between these two projects.

AMC: v3.4.10 Aerospike: 3.6.1

Thanks, Sam


#2

Both projects are getting the client connections stat from the statistics command. You can see what they are using by running:

asadm -e "asinfo -v statistics like client_connections"

When a client requests these stats it may also generate a client_connection. If you run

asadm -e "watch asinfo -v statistics like client_connections"

You will likely see this changing frequently with time.