ELK: Installing MetricBeat for collecting system and application metrics

ElasticSearch’s Metricbeat is a lightweight shipper of both system and application metrics that runs as an agent on a client host.  That means that along with standard cpu/mem/disk/network metrics, you can also monitor Apache, Docker, Nginx, Redis, etc. as well as create your own collector in the Go language.

In this article we will describe installing Metricbeat 5.x on Ubuntu when the back end ElasticSearch version is either 5.x or 2.x.

Agent Installation

Start by adding the GPG key and adding the ES repository:

$ wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -

$ sudo apt-get install apt-transport-https ca-certificates -y

$ echo "deb https://artifacts.elastic.co/packages/5.x/apt stable main"| sudo tee -a /etc/apt/sources.list.d/elastic-5.x.list

Then refresh the repository and install Metricbeat:

$ sudo apt-get update
$ sudo apt-cache policy metricbeat
$ sudo apt-get install metricbeat

The System-V init script links are already present so there is no need to run update-rc.d as stated in the official docs.  You can see those links using ‘sudo ls /etc/rc*.d | grep metricbeat’.

If during the apt-get update, there is an error stating ‘The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY …’, then you need to add the ElasticSearch signing key to the trusted keys

$ sudo apt-key adv --keyserver hkp://pgp.mit.edu:80 --recv D88E42B4

Server Index Configuration

Next, we need to tell ElasticSearch how to interpret and analyze the data that Metricbeat will be sending.  This json file comes with Metricbeat, and we will submit it to the server.

$ sudo apt-get install curl -y
$ curl http://esmaster1:9200

The curl to the base ElasticSearch port will return general information about the ES server including the version (“number”).  Now load the index settings according to the ES version.

For ElasticSearch 2.x

$ curl -XPUT 'http://esmaster1:9200/_template/metricbeat' -d@/etc/metricbeat/metricbeat.template.json

For Elasticsearch 5.x

$ curl -XPUT 'http://esmaster1:9200/_template/metricbeat' -d@/etc/metricbeat/metricbeat.template-es2x.json

If you need to validate which index is active you can retrieve it:

$ curl -XGET 'http://esmaster1:9200/_template/metricbeat' | python -m json.tool | more

An easy way to tell the difference between the 2.x and 5.x versions is that in the first few lines it defines the normalization factors using the key “norms”.  For the ElasticSearch 5.x settings, you will see:

"norms": false

While in the ElasticSearch 2.x settings, you will see:

"norms": { "enabled": false }

Agent Configuration

Now we configure the Metricbeat agent at ‘/etc/metricbeat/metricbeat.yml’.  The only mandatory change is to change the output.elasticsearch.hosts it points to, but I’ve also tweaked it so it does not monitor all processes, collects every 30 seconds, and logs to an explicit location with rotation.

- module: system
  # CPU stats
  - cpu

 # System Load stats
 - load

 # Per CPU core stats
 #- core

 # IO stats
 #- diskio

 # Per filesystem stats
 - filesystem

 # File system summary stats
 - fsstat

 # Memory stats
 - memory

 # Network stats
 - network

 # Per process stats
 - process

 # Sockets (linux only)
 #- socket
 enabled: true
 period: 30s
 #processes: ['.*']

 # filter NIC
 # https://www.elastic.co/guide/en/beats/metricbeat/current/metricbeat-metricset-system-network.html\
 #interfaces: [eth0]

#========== General

# name: myhostname

# tags: ["service-X","web-tier"]

# fields:
#   datacenter: US
#   env: dev

#========== Outputs

  hosts: ["esmaster1:9200"]

#========== Logging

  level: debug
  to_files: true
  to_syslog: false
  path: /var/log/mybeat
  name: metricbeat.log
  keepfiles: 7

Run the Metricbeat Agent

Now we are ready to start the agent.

$ sudo service metricbeat start

And activity can be monitored in the log:

$ tail -f /var/log/metricbeat/metricbeat

If you are getting successful publishing to the ElasticSearch server, you will see messages like:

2017-04-16T16:19:19Z DBG  PublishEvents: 25 events have been  published to elasticsearch in 16.12336ms

And if there are issues sending the data, you will see messages like:

2017-04-16T16:20:27Z ERR Connecting error publishing events (retrying): Get http://esmaster1:9200: lookup esmaster1: no such host

Validate in ElasticSearch

You can verify that the ‘metricbeat-YYYY.MM.DD’ index is being populated by querying for the last few records, or asking for a total count.

$ sudo apt-get install curl -y
$ curl -XGET 'http://esmaster1:9200/metricbeat-*/_search?pretty=true&q=*:*&size=2'
$ curl -XGET 'http://esmaster1:9200/metricbeat-*/_count'

Validate from Kibana

If you have an instance of Kibana, you need to first add the index by going to Settings.  Use the pattern “metricbeat-*”, select “@timestamp” for the time-field name, and press “Create”.

Now you should be able to go to “Discover” and on the left hand column, you will find a “metricbeat-*” data source.  When you select this, it will show you the latest data from those indices.