ALOHA load balancer
ALOHA monitoring using Cacti

Before starting

We suppose you already have Cacti installed and running properly.

In order to configure SNMP in the ALOHA, please refer to Appnote #0056 – Monitoring the ALOHA through SNMP.

Cacti configuration update

Some graph label may be long, so it is recommended to update the Maximum Field Length of your Cacti deployment, like described below:

• Go on your Cacti console
• Click on Settings in the left menu
• Click on the visual tab
• Update the value of the row named Maximum Field Length to 100
• Click on Save button at the bottom of the page

SELINUX configuration

On some Operating system (such as redhat or centos), SELINUX is installed and started.

It may also prevent Cacti to work properly: Cacti may generate some errors related to unavailable files even if they are available and accessible.

Two options available here:

1. Setup properly SELINUX to allow right access to files
2. Simply disable SELINUX

SELINUX configuration is outside the scope of this document.

SNMP client library

The Cacti server acts as a SNMP client and the ALOHA Load-Balancer is the SNMP server.

The ALOHA delivers some counters over 64bits hence the client must be compatible with it.

The SNMP library Net-SNMP version 5.5 and above is compatible with 64 bits counters.

ALOHA plugin integration into Cacti

Integration of ALOHA plugin in Cacti can be performed in 2 steps:

1. on the Cacti server itself: integration of resources and scripts
2. through the Cacti GUI: integration of the templates

Downloading ALOHA Cacti plugin

You can download the ALOHA plugin from Exceliance’s website:

http://www.exceliance.fr/download/aloha/utils/cacti/

ALOHA plugin resource and scripts integration

Upload the aloha_cacti.tar.gz archive onto the server and untar the archive.

The archive provides two directories: resource and scripts. You just need to copy the content of the directories as explained below:

• resource directory into <path_cacti>/resource/
• scripts directory into <path_cacti>/scripts/

ALOHA plugin template integration

Get the aloha_cacti.tar.gz archive on your desktop and untar the archive. The archive contains a couple of XML files:

• cacti_host_template_aloha_-_script_query_name_based.xml
• cacti_host_template_aloha_-_snmp_query_id_based.xml

To install them, please do:

1. Get connected on Cacti console
2. From the left menu, click on import template
3. Click on choose file
4. Point to the XML file you want to import
5. Click on import

Introduction to ALOHA Cacti template

Two templates are provided:

1. cacti_host_template_aloha_-_snmp_query_id_based.xml
   collect data through fixed SNMP OIDs
2. cacti_host_template_aloha_-_script_query_name_based.xml
   collect data based on object names

Either template is fine to use. Choosing which one to use is simple as well: use the one whose targeted data won’t change over time.

If you fixed the SNMP OIDs in LB Layer 7 configuration (HAProxy), then use the first one.

If you never ever change object names in your configuration and you don’t want to fix OIDs, then the second one is fine.

Fixed SNMP OID

You have to fix objects (frontend, backend and servers) IDs in HAProxy’s configuration. Please refer to Appnote #0056 – Monitoring the ALOHA through SNMP to learn how to do this.

Object name

The template comes with a collection of scripts which can be used to collect data based on frontend, backend, server and director names

Cacti graph templates

The template allows to graph the following CPU/memory information:

• Aloha – Advanced CPU
• Aloha – CPU
• Aloha – Memory

Cacti data queries

ALOHA Layer4 Director

In the template, it is labelled as Aloha L4 Director:

ALOHA Layer4 Servers

In the template, it is labelled as Aloha L4 Servers:

ALOHA Layer7 Backend

In the template, it is labelled as Aloha L7 Backend:

ALOHA Layer7 Frontend

In the template, it is labelled as Aloha L7 Frontend:

ALOHA Layer7 Server

In the template, it is labelled as Aloha L7 Server:

Gauge or counters

What is a gauge and when to use it

A gauge is an information which is true at the time of the SNMP request.

It is preferable to monitor such type of information for data which vary a little over the time, like protocols based on connections established for a long period of time.

What is a counter and when to use it

A counter is an information which is continuously incremented over the time.

It shows the counter’s variation along the time, between two polling events. The reported value is an average of the counter between two polls.

It is preferable to monitor such type of information for data which vary very quickly over the time, like protocol with short and quick connections.

Inserting an ALOHA into Cacti

In order to add a new ALOHA Load-Balancer into an existing Cacti, follow the steps bellow:

1. Get connected on Cacti’s console
2. On the left menu, click on Management > devices link
3. In the freshly opened page, click on the Add button (from the Devices title line)
4. Fill up the following information:
   • Description: ALOHA hostname
   • Hostname: ALOHA IP address or hostname
   • Host template: ALOHA – Script query (name based) or ALOHA – SNMP query (oid based)
   • SNMP version: v2
   • SNMP community: the one you setup into your ALOHA
5. Click on create

Graphing ALOHA data

In order to create graphs for your ALOHA Load-Balancer into Cacti, follow the steps bellow:

1. get connected on Cacti’s console
2. On the left menu, click on Management > devices link
3. Click on the link corresponding to the ALOHA you want to add graphs to
4. On the ALOHA’s page, click on the link Create Graphs for this Host
5. Just check boxes for the graphs you want to add and the type of select the type of information to monitor