check_es-split-brain.py

#!/usr/bin/python
from nagioscheck import NagiosCheck, UsageError
from nagioscheck import PerformanceMetric, Status
import urllib2
import optparse

try:
    import json
except ImportError:
    import simplejson as json

class ESSplitBrainCheck(NagiosCheck):

  def __init__(self):

    NagiosCheck.__init__(self)

    self.add_option('N', 'nodes', 'nodes', 'Cluster nodes')
    self.add_option('P', 'port', 'port', 'The ES port - defaults to 9200')

  def check(self, opts, args):
    nodes = opts.nodes.split(",")
    port = int(opts.port or '9200')
    masters = []
    responding_nodes = []
    failed_nodes = []

    for node in nodes:
      try:
          response = urllib2.urlopen(
                      r'http://%s:%d/_cluster/state/nodes,master_node/'
                      % (node, port))
          response_body = response.read()
          response = json.loads(response_body)
      except (urllib2.HTTPError, urllib2.URLError), e:
          failed_nodes.append("%s - %s" % (node, e.reason))
          continue

      if type(response) is dict:
        cluster_name = str(response['cluster_name'])
        master = str(response['nodes'][response['master_node']]['name'])
        responding_nodes.append(node)
        if master not in masters:
          masters.append(master)

    if len(responding_nodes) == 0:
      raise Status('Unknown',
                   "All cluster nodes unresponsive:\r\n"
                   "%s" % (str("\r\n".join(failed_nodes))))
    elif len(masters) != 1:
      raise Status('Critical', "%d masters (%s) found in %s cluster"
                   % (len(masters), str(", ".join(masters)), cluster_name))
    else:
      if len(failed_nodes) == 0:
        raise Status('OK', "%d/%d nodes have same master"
                     % (len(responding_nodes), len(nodes)))
      else:
        raise Status('OK', "%d/%d nodes have same master\r\n"
                     "%d unresponsive nodes:\r\n%s"
                     % (len(responding_nodes),
                        len(nodes),
                        len(failed_nodes),
                        str("\r\n".join(failed_nodes))))

if __name__ == "__main__":
    ESSplitBrainCheck().run()