carboncrelay

Table of Contents

1. Module Description
2. Setup
   • What carboncrelay affects
   • Setup requirements
   • Beginning with carboncrelay
3. Usage
4. Limitations
5. Development

Module Description

Configures carbon-c-relay

Carbon C Relay is a high performance relay for the Graphite (carbon) protocol. It features: multiple destinations with rules, rewrite rules...

Setup

Setup Requirements

This module uses stdlib and hpclib.

Beginning with carboncrelay

On top of the base class, it is necessary to configure at least a destination cluster and a match rule:

include ::carboncrelay

::carboncrelay::cluster{ 'graphite_cluster':
  destinations => {
    'graphite.example.com' => {
      'port' => '2003',
    },
  },
}

::carboncrelay::match{ 'catchall':
  expression   => '*',
  destinations => ['graphite_cluster'],
}

Usage

Resource: cluster

The cluster resource define a destination cluster for the metrics. A cluster is defined by a set of destinations and a rule for choosing the destinations.

The destinations parameter accepts a hash: 'hostA' => { 'port' => '2003' }, 'hostB' => { 'port' => '2003' }, 'hostC' => { 'port' => '2003' },

The types are:

• forward: sends metrics to all destinations
• any_of: each metric is sent to only one destination (load balancing)
• failover: the metrics are sent to the first responding destination

Resource: match

A match rule tells carbon-c-relay to send metrics matching a particular pattern to a destination cluster.

Rules are applied in a specific order, so if a rule must be applied first the orders should be tweaked. The rule can have a stop parameter that tells carbon-c-relay to not look at following rules.

Resource: rewrite

carbon-c-relay can be configured to rewrite metrics name. Since graphite metrics are stored in a tree like structure. This permits to move metrics in the tree before sending them to storage.

The following example move job metrics from a particular host to a specific tree with all the job metrics:

# <cluster>.<node>.slurmd-job_36.cpu-user -> <cluster>.slurmd.<node>.job-36.cpu-user
::carboncrelay::rewrite { 'slurmd_host_swap':
  expression  => '^(.*)\.(.*)_?.*\.slurmd-(.*)\.(.*)$',
  replacement => '\1.slurmd.\2.\3.\4',
}

Limitations

This module is mainly tested on Debian, carboncrelay is not packaged on RHEL and derivatives.

Development

Patches and issues can be submitted on GitHub: https://github.com/edf-hpc/puppet-hpc