Using resource group templates

You can create resource group templates to generate resource groups, which search your topology database for instances that match its conditions. These resource groups are then listed on the Resource management page.

Before you begin

You must have the admin role inasm_admin assigned to you. See the Configuring DASH user roles topic for more information.

About this task

You can create a new template, or edit or delete an existing template.

To create a new template, you construct a topology view centered around a seed resource. This lets you search your database for topologies with resources and relationships that match the conditions defined in the template.

These defined topologies are dynamically generated, maintained and updated, and can be searched for and accessed via the Resource management page. Resource groups are dynamically refreshed when accessed.
Dynamic changes to resource group
If edges or resources are removed that render an existing resource group that has already been indexed incomplete, it will remain available, and can therefore still be found and displayed via the search functionality, or via a previously created direct URL.
If edges or resources are added or changed that render a resource group that was not indexed previously complete, the resource group will be indexed automatically, thereby becoming accessible via the search service.
Restriction: If you delete a template and associated rule, and then immediately recreate the same template and rule with the same name, the resource groups are not dynamically recreated when an observer job is run. To avoid this, do one of the following:
  • Before recreating the template and rule with the same name, run an observation to remove the initial groupTokens parameter from the resources. If you then recreate the template and rule following this step, the new groupTokens parameter will be applied and the desired resource groups will be recreated during any subsequent observations.
  • Alternatively, give the new template a different name.
Tip: Searching for and then rendering resources is described in more detail in the Search section of the UI reference topic.
Template types: Choose from three different template types to group your resources.
Dynamic template
A dynamic template automatically finds and updates multiple resource groups based on your criteria, and on how your applications and infrastructure change.
A dynamic template builds multiple resource groups that are similar to the specified seed resource, and relationship or resource type criteria. Resource group creation and membership is dynamically maintained based on the available topology data and how it changes.
For example, you can use a dynamic template to create dynamic resource groups, one for each of your virtual machines and the Kubernetes services they are running. Resource groups are then added, removed, and updated as you add or remove virtual machines or services running on them.
Tag-based template
This template creates and updates a single resource group containing the resources that have a specified set of tags.
Resource group membership is dynamically maintained to reflect changes in the topology for resources that gain or lose the specified tags.
For example, you can use a tag-based template to create a dynamic resource group tagged with both 'red' and 'green'. Then, when you add new resources with both of those tags, the resource group will be updated to include them.
Token templates
A token template applies rules to resources as they are received via observer jobs.
Token templates are based on rules which use resource parameters as tokens, whose values then become group names for groups which will contain the resources to which each rule is applied. A distinct group is created for each token value.
To form group names from multiple resource property values, you can construct rule tokens using variable substitution (as is possible with all rules).
Exact template
An exact template creates and updates a single resource group centered on a specified seed resource, on your criteria, and on how your applications and infrastructure change.
The membership of the resulting resource group includes the seed resource and those matching the specified relationship or resource type criteria. Resource group membership is dynamically maintained for the resulting resource group provided the specified seed resource type remains unchanged.
For example, you can use an exact template to create a resource group only for a specific Jenkins build pipeline, any new builds or physical servers, and its connected network switch.

Procedure

Access the Resource group templates page

  1. Log in to the console.
  2. From the main navigation, click Administration > Topology management.
    The Topology management page is displayed.
  3. Click Configure on the Group templates card.
    The Resource group templates page is displayed listing existing templates in a table format by name, type, number of resource groups, description, user, and date modified.
    Tip: To reduce the number of templates displayed in the table, use the Filter table text field. The items displayed are filtered as you enter the search text.
    From here, you can perform the following actions:
    • To reload the templates, click Refresh (top right). This can be useful if other users are customizing the templates.
    • To delete an existing template, select it in the table, then click Delete topology template. If you intend to recreate the template, be aware of the restrictions.
    • To edit an existing template, select it in the table, then click Edit topology template.
      Note: When you edit an existing template, the template definition and topology areas are already populated. Also, the Name and Type parameters cannot be edited. You edit the other parameters as for a new template, and when you do, the template definition and topology areas will change. If you require a template with a different name, you must create a new template.
    • To create a new template, click Create a new template (top right). You are presented with a choice of template types. Select either a Dynamic, Tag based, Token, or Exact template, then click Start.

Define a template

The Template builder page is displayed, consisting of a topology view area on the right, and a number of template definition fields on the left.

  1. For new templates, enter a unique Template name (required).
  2. Enter/edit the Description (optional).
  3. For new templates, select an existing type from the Resource group type drop-down, or select Custom type from the drop-down.
    If you select Custom type, a new text box opens, where you type a name for your new resource group type.
  4. Define a resource group name or naming pattern.
    For tag templates
    Provide a resource group name.
    For token templates
    No resource group name is defined, as groups are automatically named based on the rule tokens.
    For Dynamic and Exact templates
    The seed name of the resource group is used when a resource group is generated, but you can define either a prefix, suffix, or both to create an appropriate name for each of the dynamically generated resource group.
    Remember: Although an exact template type focuses on a single resource, it remains dynamic, which means as long as the seed resource itself remains unchanged, the defined topology can change through the removal or addition of connected resources or relationships.
  5. Choose an icon to associate with the template from the drop-down, or click (+) to create a new icon.
    All resource groups based on this template will display the icon.
  6. Enable or disable correlation of event groups on topologies: correlation toggle
    For more information, see: Displaying analytics details for an event group
  7. Enter a tag to be appended to each resource group, then click Add tag.
    Restriction: The following special characters are not supported when specifying tags: 
    . ? + * | { } [ ] ( ) " \ # @ & < > ~
  8. Complete the following steps (depending on the type of template you are building):
    For Dynamic, Tag and Exact templates
    Use Search for a seed resource (or tag).
    • As you insert your cursor into the Search field, the five most recent searches are listed and can be selected. You can delete a recent search by clicking the delete button (X) to the right of the suggested search.
    • If you type in a search term, suggested search results are listed, which contain results both from the topology database and from recent searches, with your entered search text highlighted.
    When you select a search result, the found resources are listed by 'Resource name', 'Type' and 'Tags'. You can expand a resource to display its properties and values, or click its name to render a basic topology view centered around the resource as seed. The topology is displayed on the right of the Template builder.
    For Token templates
    Use the right hand side of the screen to define a new rule.
    Details
    Enter a unique Name for the rule.
    Define the Tokens for the rule, then click Add+. You can use variable substitution to combine more than one property value if required.
    Conditions
    Select observers to which this rule applies from the Observer name drop-down, or leave empty for all observers.
    Select providers to which this rule applies from the Provider name drop-down, or leave empty for all providers.
    Select resource types to which this rule applies from the Resource type drop-down, or leave empty for all resource types.
    Set the Token filter mode to either Exclude or Include, then define a filter (or filters) in the format of a regular expression.
    Exclude
    Tokens which match any one of the expressions will not be applied to resources.
    Include
    Only tokens which match one of the expressions will be applied to the applicable resources.
    Optionally, you can validate the filters using the Validate token filters button.

Refine the template (`Exact` and `Dynamic` templates only)

  1. Use the topology view tools to refine the topology.
    Use the context (right-click) menu to view the resource's details, see which observer job generated it and when, get its neighbors, or follow adjacent relationships. You can increase the hop count, open a timeline view, or change its layout. For more information on working with topologies, see the Viewing a topology topic.
    As you define the topology and with it the template conditions, a preview function retrieves information from the topology database, indicating the number of matches.
    Tip: The previous limit of 5,000 no longer applies, but you may want to consider that a large number of matches will take longer to generate and maintain.
  2. You can define additional tags and other optional elements for the template.

Preview and generate resource groups

  1. Depending on template type, complete the following steps.
    • For `Exact`, `Dynamic` and `Tag` templates: You can preview the resource groups that will be discovered by the template.
      1. Click Preview resource groups. A list of resource groups is displayed.
      2. Preview individual resource group topologies to verify that they meet your requirement. If they do not, refine your template further.
      3. Once your template meets all of its required conditions, click Save template & generate resource groups.
    • For `Token` templates: A token template only applies its rules and creates groups as new observations are received from its designated observers, and therefore cannot be previewed.
      • Click Save template.
  2. Define a default layout for the resource groups.
    When a resource group based on this template is selected in the Topology Dashboard, the default layout you specify here is used.

Results

Resource groups created from the templates are saved in the topology database, and can be viewed on the Resource management page and the Topology dashboard.
Remember: Resource groups are updated automatically when the topology database is updated, and generated dynamically as they are displayed.

What to do next

Resource groups can be searched for by operators using the standard Search functionality, and then accessed as topologies, or added to applications. Searching for and then rendering resources is described in more detail in the Search section of the UI reference topic, and in the Managing services and viewing topologies topics.