check a zookeeper quorum size from jmx

gistfile1.rb

require 'java'

import javax.management.ObjectName
import javax.management.remote.JMXServiceURL
import javax.management.remote.JMXConnectorFactory

host   = "zk-a835862a.tld"
port   = 10010

config = {
  url: "service:jmx:rmi:///jndi/rmi://#{host}:#{port}/jmxrmi",
  metric_query: "org.apache.ZooKeeperService:name0=ReplicatedServer_id*,name1=replica.*",
}

# setup connection
jmx   = JMXConnectorFactory.connect JMXServiceURL.new config[:url]
mbean = jmx.getMBeanServerConnection

# query for replica beans
zookeeper_quorum_replicas = mbean.queryMBeans ObjectName.new(config[:metric_query]), nil
zookeeper_quorum_size     = zookeeper_quorum_replicas.size