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Amazon EBS

Overview​

Amazon Elastic Block Store (Amazon EBS) provides block level storage volumes for use with EC2 instances. EBS volumes behave like raw, unformatted block devices. You can mount these volumes as devices on your instances. You can mount multiple volumes on the same instance, and you can mount a volume to multiple instances at a time. You can create a file system on top of these volumes, or use them in any way you would use a block device (like a hard drive). You can dynamically change the configuration of a volume attached to an instance.

The Amazon EBS Centreon Plugin uses the Amazon Cloudwatch API to collect the related EBS metrics.

Monitoring Connector assets​

Monitored objects​

  • EBS volumes: standard, gp2, st1, sc1 & io1

Discovery rules​

Rule nameDescription
Cloud-Aws-Ebs-Api-HostDiscoveryDiscover EBS volumes

Monitored metrics​

You can get more details on Amazon EBS Cloudwatch metrics in the official AWS documentation: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using_cloudwatch_ebs

Metric nameDescription
VolumeReadBytesProvides information on the read operations in a specified period of time. Unit: Bytes
VolumeWriteBytesProvides information on the write operations in a specified period of time. Unit: Bytes

Prerequisites​

AWS Configuration​

Configure a service account (access/secret keys combo) for which the following privileges have to be granted:

AWS PrivilegeDescription
ec2:DescribeVolumesDescribes the specified EBS volumes or all of your EBS volumes.
cloudwatch:getMetricStatisticsGet metrics from the AWS/EBS namespace on Cloudwatch

Plugin dependencies​

To interact with Amazon APIs, you can use either use the awscli binary provided by Amazon or paws, a Perl AWS SDK (recommended). You must install it on every Centreon poller expected to monitor Amazon EBS resources: 

yum install perl-Paws

For now, it is not possible to use paws in the following situations:

  • if you are using a proxy to reach AWS Cloudwatch APIs.
  • to automatically add Hosts in Centreon using the Host Discovery feature

Setup​

  1. Install the Centreon package on every Centreon poller expected to monitor Amazon EBS ressources:
yum install centreon-plugin-Cloud-Aws-Ebs-Api
  1. On the Centreon Web interface, install the 'Amazon EBS' Centreon Monitoring Connector on the Configuration > Monitoring Connector Manager page

Configuration​

Log into Centreon and add a new Host through "Configuration > Hosts". Select the Cloud-Aws-Ebs-custom template to apply to the Host.

Once the template applied, some Macros have to be configured:

MandatoryNomDescription
XAWSSECRETKEYAWS Secret key of your IAM role. Password checkbox must be checked
XAWSACESSKEYAWS Access key of your IAM role. Password checkbox must be checked
XAWSREGIONRegion where the instance is running
XAWSCUSTOMMODECustom mode to get metrics, 'awscli' is the default, you can also use 'paws' perl library
XAWSVOLUMEIDEBS Volume ID
PROXYURLConfigure proxy URL
EXTRAOPTIONSAny extra option you may want to add to every command_line (eg. a --verbose flag)
DUMMYSTATUSHost state. Default is OK, do not modify it unless you know what you are doing
DUMMYOUTPUTHost check output. Default is 'This is a dummy check'. Customize it with your own if needed

FAQ​

How to check in the CLI that the configuration is OK and what are the main options for ?​

Once the plugin installed, log into your Centreon Poller CLI using the centreon-engine user account and test the Plugin by running the following command (Some of the parameters such as volume-id and proxyurl have to be adjusted):

/usr/lib/centreon/plugins//centreon_aws_ebs_api.pl \
    --plugin=cloud::aws::ebs::plugin \
    --mode=volumeio \
    --custommode='awscli' \
    --aws-secret-key='***' \
    --aws-access-key='***' \
    --region='eu-west-1' \
    --proxyurl='http://myproxy.mycompany.org:8080' \
    --volume-id='vol-1234abcd' \
    --statistic='average' \
    --timeframe='600' \
    --period='60' \
    --warning-volume-write-bytes='60000000' \
    --critical-volume-write-bytes='90000000' \
    -- verbose

Expected command output is shown below: 

OK: 'vol-1234abcd' Statistic 'Average' Metrics Volume Read Bytes: 28.40 KB, Volume Write Bytes: 54.61 MB | 
'vol-1234abcd~average#ebs.volume.bytes.read.bytes'=29081.60B;;;; 'vol-1234abcd~average#ebs.volume.bytes.write.bytes'=57261465.60B;0:60000000;0:90000000;;
AWS EBS Volume'vol-1234abcd'
    Statistic 'Average' Metrics Volume Read Bytes: 28.40 KB, Volume Write Bytes: 54.61 MB

The command above monitors the Volume IOs (--mode=volumeio) of the vol-1234abcd EBS volume (--volume-id='vol-1234abcd'). This volume is hosted within the AWS eu-west-1 region (--region='eu-west-1'). The collected metrics will be parsed as average statistics (--statistic='average') over a timeframe of 600 secondes (--timeframe='600') with a sample of 1 point per minute (--period='60').

This command would trigger a WARNING alert if the average writing operations on the volume are higher than 60MB and a CRITICAL alert if they're higher than 90MB.

All the options that can be used with this Plugin can be displayed by adding the --help parameter to the command:

/usr/lib/centreon/plugins/centreon_aws_ebs_api.pl --plugin=cloud::aws::ebs::plugin --mode=volumeio --help

Why do I get the following result:​

UNKNOWN: No metrics. Check your options or use --zeroed option to set 0 on undefined values ?​

This command result means that Amazon Cloudwatch does not have any value for the requested period.

This result can be overriden by adding the --zeroed option in the command. This will force a value of 0 when no metric has been collected and will prevent the UNKNOWN error message.

UNKNOWN: Command error: - An error occurred (AuthFailure) [...] ?​

This command result means that the credentials provided don't have enough privileges to perform the underlying AWS Operation.

UNKNOWN: Command error: - An error occurred (InvalidParameterValue) [...]​

Most of the time, this command result highlights typo/mispelling in the Amazon Dimension name (--volume-id).