Monitoring Resource Usage of Jobs with cAdvisor

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Introduction

Google's cAdvisor (Container Advisor) provides information about the resources used by containers. A web UI is exposed at http://hostname:port/, and in addition data is exported to a central database. For sites running a batch system with cgroups enabled, cAdvisor can provide information about running jobs on worker nodes.

More information is available here: https://github.com/google/cadvisor

The main page of the UI shows an overview of CPU, memory, network and disk usage of the whole node (the single page is split into 5 images below for an example worker node):

Cadvisor1.png
Cadvisor2.png
Cadvisor3.png
Cadvisor4.png
Cadvisor5.png

You can then drill down and view information about individual jobs.

Cadvisor6.png

Clicking on one of the listed jobs gives information about the resource usage of that job.

The web UI is of limited use as it only shows data over the past minute. Using Grafana for visualizing data collected by cAdvisor and stored in InfluxDB is more useful. Alternatively, it should be possible for cAdvisor to send data to ElasticSearch eventually https://github.com/google/cadvisor/issues/634.

Building cAdvisor

A machine with go installed is required. To prepare such a machine:

yum -y install git
yum -y install go
rpm -ivh http://mercurial.selenic.com/release/centos6/RPMS/x86_64/mercurial-3.4-0.x86_64.rpm
mkdir /var/lib/go
export GOPATH=/var/lib/go

Then

go get -d github.com/google/cadvisor
go get github.com/tools/godep
cd $GOPATH/src/github.com/google/cadvisor
$GOPATH/bin/godep go build

In the current directory the executable cadvisor will be created. It has no dependencies and can therefore be placed on any machines as necessary which need to be monitored.

Installing & configuring InfluxDB

Download and install the rpm:

wget https://s3.amazonaws.com/influxdb/influxdb-latest-1.x86_64.rpm
rpm -ivh influxdb-latest-1.x86_64.rpm

then start the service

service influxdb start

In a browser go to http://hostname:8083/ and login using the default username (root) and password (root). To create a database for cAdvisor, specify a database name in the 'Database Details' part of 'Create a Database' and click 'Create Database'.

You should see something like the following:

Influxdb1.png

Once the database has been created, click on the database name and create a user by specifying the username and password in the 'Create a New Database User' section.

More information available at http://influxdb.com

Running cAdvisor

Example usage on a worker node

/usr/local/bin/cadvisor -storage_driver=influxdb -storage_driver_host=hostname:8086 -storage_driver_db=database_name \ 
-storage_driver_password=password -storage_driver_user=user -storage_driver_secure=false -storage_driver_table=stats

where the InfluxDB hostname, database name, username and password should be changed as appropriate.


Installing Grafana

Download and install the rpm:

rpm -ivh https://grafanarel.s3.amazonaws.com/builds/grafana-2.0.2-1.x86_64.rpm

and start the service

service grafana-server start

The web UI should be visible at http://hostname:3000.

Configurating Grafana

After logging in (the default username and password are admin/admin), follow the instructions http://docs.grafana.org/datasources/influxdb/ in order to add the InfluxDB as a data source.

Grafana1.png