How to monitor elasticsearch using nagios

After a while - I've managed to monitor elasticsearch using the nrpe. I wanted to use the elasticsearch Cluster Health API - but I couldn't use it from another machine - due to security issues... So, in the monitoring server I created a new service - which the check_command is check_command check_nrpe!check_elastic. And now in the remote server, where the elasticsearch is, I've editted the nrpe.cfg file with the following:

command[check_elastic]=/usr/local/nagios/libexec/check_http -H localhost -u /_cluster/health -p 9200 -w 2 -c 3 -s green

Which is allowed, since this command is run from the remote server - so no security issues here...

It works!!! I'll still try this check_http_json command that I posted in my qeustion - but for now, my solution is good enough.

After playing around with the suggestions in this post, I wrote a simple check_elasticsearch script. It returns the status as OK, WARNING, and CRITICAL corresponding to the "status" parameter in the cluster health response ("green", "yellow", and "red" respectively).

It also grabs all the other parameters from the health page and dumps them out in the standard Nagios format.

Enjoy!

You can use this cool Python script for monitoring your Elasticsearch cluster. This script check your IP:port for Elasticsearch status. This one and more Python script for monitoring Elasticsearch can be found here.

#!/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 ESClusterHealthCheck(NagiosCheck):

    def __init__(self):

        NagiosCheck.__init__(self)

        self.add_option('H', 'host', 'host', 'The cluster to check')
        self.add_option('P', 'port', 'port', 'The ES port - defaults to 9200')

    def check(self, opts, args):
        host = opts.host
        port = int(opts.port or '9200')

        try:
            response = urllib2.urlopen(r'http://%s:%d/_cluster/health'
                                       % (host, port))
        except urllib2.HTTPError, e:
            raise Status('unknown', ("API failure", None,
                         "API failure:\n\n%s" % str(e)))
        except urllib2.URLError, e:
            raise Status('critical', (e.reason))

        response_body = response.read()

        try:
            es_cluster_health = json.loads(response_body)
        except ValueError:
            raise Status('unknown', ("API returned nonsense",))

        cluster_status = es_cluster_health['status'].lower()

        if cluster_status == 'red':
            raise Status("CRITICAL", "Cluster status is currently reporting as "
                         "Red")
        elif cluster_status == 'yellow':
            raise Status("WARNING", "Cluster status is currently reporting as "
                         "Yellow")
        else:
            raise Status("OK",
                         "Cluster status is currently reporting as Green")

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

Shameless plug: https://github.com/jersten/check-es

You can use it with ZenOSS/Nagios to monitor cluster health, data indices, and individual node heap usage.