NEP Insights¶

Extension contents¶

Each NEP Package contains the content that can be used to build the required NetEye design. The main Extension contents shipped with a package are:

Director Objects
ITOA Dashboards
Configuration elements
Monitoring Plugins

Most of these can be used without any particular limitations: an ITOA Dashboard can be opened right after its import, and both Configuration elements and Monitoring Plugins can be used immediately after placing them in the right path. Instead, Director Objects require a well-defined set of rules and best practices to be used efficiently.

Director Objects¶

Director Objects are the inner core of the entire solution. Their objective is to provide easy-to-use monitoring object definitions. Each object comes with ample support for its configuration and are organized in structures that can provide a basic and meaningful (in other words, standard) monitoring for hosts or devices. This way, there is a basic set of variables and performance data that all the other Extension contents can use to build their functionalities upon.

To ensure this, Director Objects have to be organized in self-containing blocks that can be combined preserving each own identities, data and structure. This lead to the concept of Template-Types.

What is a Template-Type¶

A Template-Type is a Template that defines a specific purpose, selecting which variables are required to ensure its purpose is completely fulfilled, and isolating them from other Template-Types. The purpose is a part of the monitored object that needs to be defined, like the kind of monitoring, how this monitoring can be done, whether or not it can be managed by a Cluster Zone, and so on. In short, a Template-Type selects an aspect of a monitored object (which can be Host or Service) and defines all the data that is needed to describe this aspect, ensuring no other Template-Type will redefine/rewrite that data.

Remember that, excluding some exceptions, objects provided by an NEP should not be edited directly: in case of an update or restore operation, all editing will be lost. If a Template must be edited, create a Child template and make any changes there.

Template-Types for Hosts¶

Template-Types have been defined for both Hosts and Services. While their names are similar, their purpose and use are not exactly the same. The next table summarizes the available Template-Types for Host Objects.

Template-Type	Host Template Name	Description
Host Monitoring	nx-ht-type-monitoring	Describes how a specific technology should be monitored by providing the required Services, Data Fields and Custom Variables
Host Location	nx-ht-type-location	Implements the concept of distributed objects with both logical position (Icinga Cluster Zones) and geographical position (address, coordinates, etc.)
Host Custom	nx-ht-type-custom	Used to overwrite Custom Variables coming from other Templates, as well as to alter Check Execution parameters, for a specific set of objects; it also provides default Check Command and Check Execution parameters to all monitored Host Objects

Each Template-Type defines and provides the (custom) variables strictly required to perform its monitoring duty. As an example, a Template-Type Host Monitoring is not supposed to define a Cluster Zone: it is not its duty to decide the Icinga Cluster Zone where it should be managed; instead, this information must be set by Template-Type Host Location. For the same reason, a Template-Type Host Location is not supposed to provide values for Icinga2 Agent and related, because it is a specific setting required for monitoring purposes. By enforcing this rule, each template can be considered a sealed box, and then all Host Objects can be created by combining different Template Types.

Template-Type: Host Monitoring¶

Templates of type Host Monitoring have the purpose of implementing a well-defined monitoring strategy for a specific technology. Each of them contains all and only those required Data Fields to configure its settings, allowing for a complete monitoring configuration at the Host Object level. That data will be used automatically by the necessary Service Objects to monitor performance and all other aspects of the same technology on that very Host Object.

All technologies are grouped into categories, with each one designed to build a hierarchy together with the others. As the concept of hierarchy implies, technologies will have more similar behaviors and settings the closer they are to each other in the hierarchy tree. This allows for quick and easy understanding of what and how an object will be monitored. Also, the design of the categories and their naming enables an intuitive way to look up for the required type of monitoring.

Templates of type Host Monitoring usually don’t provide info about how the state of a Host Object is monitored: their aim is to provide Service Objects with all the data they might require to work. Parameters like Check command, Check Interval, Retry Interval and Check Attempts are managed using templates of type Host Custom.

Template-Type: Host Location¶

Templates of type Host Location are meant for providing settings and information about the actual location of the monitored Host Objects both in terms of physical location (address or position) and monitoring location (Icinga Cluster Zone). Data provided through this kind of template is useful to group Host Objects or to restrict their access on a geographical or logical basis.

Because there is actually no standard for coding geographical or positioning data, it is the responsibility of the end user to create as many Host Location templates as he/she desires with the Data Fields that better describe its scenario.

As stated above, the use of templates of type Host Location is optional and not strictly required to build a working monitoring design.

Template-Type: Host Custom¶

Templates of type Host Custom are used to provide Host Objects having common characteristics with the same set of (Custom) Variables. Therefore, their main purpose is to overwrite settings of Host Templates in case the default values provided by the other templates are wrong. Because Host Objects with common characteristics will have the same set of overwritten variables, templates of type Host Custom are also suitable to group together Host Objects and clarify the structure of the end user’s infrastructure (e.g.: intranet servers, backup servers, core network devices, virtualization infrastructure etc.) They will thus become useful for managing Host Groups and user account authorization.

Templates of type Host Custom also have a secondary purpose: they aim to define how the state of a Host Object is monitored. Parameters like Check command, Check Interval, Retry Interval and Check Attempts must be defined using this kind of template. In fact, to ensure all Host Objects are monitored using consistent parameters, it is better to provide them with the required settings using a dedicated template instead of relying on the settings used on a multitude of Host Monitoring Templates. This is the main reason that a Host Object must be created by using one (or more) template of type Host Monitoring and one template of type Host Custom. Also, all Service Objects defined by Automations and Service Sets provided by NEPs automatically include the default Host Custom template dispatched with Package NEP Common.

Template-Types for Services¶

The next table summarizes the available Template-Types for Service Objects. While the names are similar, Template-Types for Services behave slightly different from those for Hosts.

Template-Type	Service Template Name	Description
Service Monitoring	nx-st-type-monitoring	Describes how a specific aspect of a technology should be monitored
Service Custom	nx-st-type-custom	Used to overwrite Custom Variables coming from other Templates, as well as to alter Check Execution parameters, for a specific set of objects

Each Template-Type makes use of (Custom) Variables defined in its companion Host Monitoring Template, and allows for an override of these values directly at the Service Object level (if needed).

Template-Types: Service Monitoring¶

Templates of type Service Monitoring implement a well-defined monitoring strategy for a given aspect of a specific technology. Each one has a companion HT of type Host Monitoring providing all the required (Custom) Variables to perform its monitoring duty. If for some reason, one or more Variables coming from the companion HT must be replaced, each ST provides full support for override and redefinitions.

Like HTs of type Host Monitoring, all STs of type Service Monitoring are grouped into categories designed to build a hierarchy. Unlike HTs of type Host Monitoring, all the STs of type Service Monitoring define default values for Check Command parameter. Parameters Check Interval, Retry Interval and Check Attempts can be managed via Service Custom Templates if required.

Template-Types: Service Custom¶

Templates of type Service Custom are used to manage Check Execution parameters and overwrite (Custom) Variables coming from other ST where it is needed. In case a Service Object needs different Check Execution parameters or it must be provided with other (Custom) Variables, this Template-Type can be used to perform this task.

How to create Objects using Template-Types¶

Creating Objects using Template-Types is quite simple. They can be viewed as building-blocks that can stick together in the right quantity. Some of them are mandatory, others can be used only if their functionalities are required. This means this paradigm relies heavily on Multiple Inheritance.

To create Host Objects, one Template of type Host Custom and one or more of type Host Monitoring are strictly required: the Host Custom type provides Check command and Check Execution parameters, while the Host Monitoring type provides the Data Fields that Service Objects can use. Host Objects created this way will be assigned to the Icinga Master Zone. If Distributed Monitoring is required, or if Host Objects needs to be classified by geographical or logical location data, only one Template of type Host Location can be used.

To be more specific, a Host Object must be built following these steps. To obtain the maximum advantage using this paradigm, be sure to import all the Templates in the displayed order.

Add one or more HT of type Host Monitoring
Add one HT of type Host Location (Optional)
Add one HT of type Host Custom

Like Host Objects, Service Objects must be built following these steps:

Add one ST of type Service Monitoring
Add one ST of type Service Custom (Optional)

Because Service Templates of type Service Monitoring provide their own Check Command, the use of type Service Custom is not strictly required. If not used, default values for Check Interval (5 minutes), Retry Interval (1 minute) and Check Attempts (3) will be used by Icinga 2. However, all Service Objects provided by Automations and Service Sets provided by NEPs automatically include the default Service Custom Template dispatched with Package NEP Common.

The outlined order is, for both Host Objects and Service Objects, the one that is used when designing an NEP Package, therefore it already includes the optimal behavior for each object. While each Template-Type acts as a sealed box, there might be cases when variables are managed by two different Template-Types. In this cases, since Host Monitoring Templates or Service Monitoring Templates must not be edited, inheritance order matters and can influence the final behavior significantly. Therefore, it is strongly suggested that you enforce the order outlined above for every created objects.

Predefined Service Sets¶

Basic monitoring for Host Objects is defined by grouping Templates of type Service Monitoring into Service Sets. Those Service Sets will be assigned to Host Objects based on the Host Monitoring Templates used to create the Host Objects themselves, and use default timings and settings provided by the default Service Custom Template. While this allows for easy and quick startup, it might not be suitable over the long term. If these Service Sets must be customized or replaced, the best suggestion is to disable all the contained Services and create your own Service Sets to use.