32 Configuration Management

Lecture 4:I. Configuration Management

I. Introduction

• Definition (from Wikipedia): "Configuration Management (CM)management is a process that tracks all of the individual configuration items (CIs) withinin an IT system.system, Thiswhich systemmay canbe rangeas fromsimple as a single server toor as complex as an entire IT department."
The
• keyWhat is trackinga and managing the components.

II. Core Concepts: Configuration Items (CIs) and the CMDB

• Configuration Item (CI):?

  • Any component that needs to be managed to deliver an IT service. This is the fundamental building block of CM.
    • Examples: Servers, network switches, routers, software, desktops, laptops, virtual machinesmachines.
    (VMs).
    • Can be tangible (physical hardware) or intangible (software, services).
    • Large Scale:organizations Acan maturehave CMDBmillions of CIs in atheir largeCMDB.
    organization
    can contain millions of CIs.
  • CI Class: A category or type of CI.CIs Think of it like a folder structure.
    • Example:(e.g., "Servers"). isClasses acan CIhave class.
    child
    • Childclasses Classes:(e.g., "Windows Servers" andServers," "Linux Servers" could be child classes of "Servers"). This creates a hierarchy.
  • CI Records:Tables:
    • CIs are stored as records in the CMDB_CIcmdb_ci table (or one of its many extended tables)tables.
    within ServiceNow.
    • Each CI class has its own table.
    table
    • (this Relationships:is Thecrucial configurationfor item'srelationships). relationships.There are hundreds of out-of-box CMDB tables.

  • Configuration Management Database (CMDB): The database that stores all the CIs and their relationships. It's the heart of configuration management.

  • CI Relationships: CIs are connected to each other through defined relationships. These connections are crucial for understanding dependencies.

    • CIs Example:can Ahave serverfew or many relationships to other CIs.
    • Relationships are defined using supportsverbs anthat email service. "Supports" isdescribe the relationship.connection (e.g., "supports," "depends on," "used by").
    • Directionality: Relationships have direction:
      • Upstream: Towards applications or applications/services (e.g., "supports"Server supports Email Service").
      • Downstream: Towards hardware or infrastructure (e.g., "Email Service is supported by"by Server").
    • Complexity: CIs can have few or many relationships, depending on their role.

  III. Purpose and Benefits of a CMDBCMDB:

  • Dependency Views/Maps: Visual representations of CI relationships.relationships, These are extremely powerful for understandingshowing how differenteverything parts of the IT infrastructure areis connected. This is a key feature.
  • Troubleshooting: Helps identify the root cause of incidents and problems more quickly by showing dependencies.
  • Change Management: Reduces conflicts during changes by showing the potential impact of changes on otherrelated systems.CIs.
• CMDB Granularity: A CMDB can be as detailed as an organization needs.needs, It might startstarting with only critical systemscomponents and expandexpanding over time.
• ResourcePopulating Investment:the CMDB: Building
  and
  • No maintainingeasy atask.
  CMDB
  • Options: requires
    resources
    • Manual import (people, tools, processes)spreadsheets).
    • Data Population: CIs can be added to the CMDB through:
      • Manual Import: Importing data from spreadsheets.
      • Automated Tools: Using discovery tools like (ServiceNow Discovery orDiscovery, Microsoft SCCM. These tools automatically find and populate CIs.SCCM).
    • Data Freshness:Crucial: A CMDB must be kept up-to-date to be valuable. Stale data leads to inaccurate information. Processesprocess for creating and updating CIs areis essential.essential to keep the CMDB accurate and valuable. A stale CMDB is not useful.

  IV.II. Demo: Configuration Management in ServiceNow (Practical Demonstration)

  • Configuration Application: The main area within ServiceNow for managingHas the CMDB.most It has a lotmodules of modulesany becauseapplication eachdue to the large number of CI class often has its own module.

    classes.

  • Exploring CI Records:

    • Application Servers (Example):
      • cmdb_ci_app_serverAll): module: Shows all CIs with a class of Application Server (or its child classes).
      • CI Form View: Shows the properties of a specific CI (e.g., Name, Category, Version, Managed By, Support Group, TCP Ports).
      • Related Items: Shows relationships to other CIs representing(this applicationis serversa critical section).
    • Servers (Example):
      • All module: Shows all CIs with a class of Server.
      • CI Form View: More detailed hardware-specific properties (Asset Tag, Manufacturer, OS, RAM, CPU, etc.).
      • Related Items: Shows relationships (e.g., a Javaphysical server supporting application server)servers). The form view shows details like name, category, version, managed by, support group, and related items (relationships).
      • Servers (cmdb_ci_server): Shows CIs representing physical servers. The form view includes hardware-specific details like asset tag, manufacturer, OS, RAM, CPU, etc.

    • Key ServiceNow Modules:

      • CI Class Manager:
        • A centralsingle placeinterface to view the CMDB hierarchy ofand allconfigure CI classes and their configurations (fields, relationships, etc.). Provides a "singlehigh-level paneoverview.
        of
        glass."
      • CMDB Groups: Allows creating groups offor managing CIs (e.g., a "Servers AdminAdmin" Group")group).
      • CMDB Query Builder: A graphical tool for building queriesCMDB to find specific CIs based on criteria.queries.
      • Business Services:
        • Services essentialthat forthe business operationsrelies on (e.g., email,Email, tradingTrading software)Software).
        These
        • areNot high-levelthe CIs.physical Thecomponents, dependencybut viewthe isservice particularly important at this level.itself.
        • Dependency View Button:(Crucial): Loads the dependency map, a visual representation ofShows the relationships between athe business service and other CIs. Shows upstreamCIs (supported services)upstream and downstreamdownstream). (supportingThis infrastructure)is dependencies.a powerful visualization. The demo shows the Email service and its connections to servers, storage, etc.
      • Mass Storage Devices:Device (Example): Example
        of
        • A CI representing a low-levelstorage CIarea network (infrastructure)SAN).
        that
        • Dependency View: Shows how the storage device supports many other CIs.CIs The(email dependencyservers, database servers, web servers). This demonstrates the bottom-up view showsof alldependencies.
        the
        systems that rely on this storage.
      • CMDB Dashboards: Provide visualcharts overviewsand ofgraphs thefor visualizing CMDB data (charts,requires graphs,sufficient statistics)data to be meaningful).
      • CMDB Classifications:Classification Sections: The bulk of the Configuration application, listing modules for various CI classes (Application Servers, Servers, Clusters, Databases, etc.). Each has an "All" module to list all records of that type.
      • Relationships Section:Section (Important): Crucially important for defining the types of relationships between CIs.
        • CI Relationship Types: PredefinedDefines the verbs used for relationships (e.g., "depends on," "used by," "contains," "runs on"). These defineare thepre-defined, typebut ofcan connectionbe between CIs.customized.
        • CI User Relationship Types: Relationships between CIs and users.
        • CI GroupSuggested Relationships: RelationshipsPre-defined betweenrelationships CIsthat andcan groups.
        be
        • Suggested Relationships: Pre-configured, based on ServiceNow.applied.
      • CI Identifiers: UniqueA list of identifiers for different CI types of(each CIs. Each identifier haswith its own table.
      table).

    • CreatingAdding CI Relationships Manually:(Manually):

      • Navigate toOn a CI recordrecord, (e.g.,click anthe application+ server).button in the Related Items section.
      • ClickThis opens the "+" button under "Related Items" to add a relationship.
      • Use the Relationship Editor:
        Editor.
        • Shows existing relationships (parent/child)Parent/Child).
        • Suggested Relationship Types: Provides suggesteda filter to find related CIs.
        • The relationship typesis (e.g., "depends on," "runs on").
        • Allows selecting another CI to create the relationship.
        • Displays the relationshipdescribed in both directions (e.g., "A sendsdepends data toon B" and "B receivesis dataused fromby A").
      • SaveSaving the relationship.
      relationship
      • Viewupdates the updatedRelated dependencyItems map to seeand the newDependency connection.View.

    • Automated Relationship Creation (ServiceNow Discovery):Relationships A

      more
      • Manually advancedadding topic.relationships is impractical for large CMDBs.
      • ServiceNow Discovery can automatically create relationships,relationships which(more isadvanced essentialtopic).
      for large CMDBs where manual creation is impractical.

    V. Key TakeawaysTakeaways:

    • Configuration Management is about tracking and managing IT components (CIs).
    • The CMDB is thea central databaserepository forof storinginformation CIsabout IT components and their relationships.
    • CI Classes and their hierarchy are fundamental to organizing the CMDB.
    • Relationships are crucialkey forto understanding dependencieshow CIs are connected and the impact of changes.changes or outages.
    • Dependency Views are a powerful visualization tool for understanding complex relationships.
    • ServiceNow provides tools for managingboth CIs, defining relationships,manual and visualizingautomated dependencies.CMDB management.
    • Automated discoveryMaintaining an accurate and up-to-date CMDB is essential for large-scaleeffective CMDBs.
    IT
    • Keepingoperations. theThe CMDB up-to-date is criticala foundational element for itsIncident, effectiveness.Problem, and Change Management, as well as other ITIL processes.

    This detailed summary breaks down the lecture into its core components, making it easier to understand and use as study material. It emphasizes the key concepts, the practical aspects within ServiceNow, and the overall importance of configuration management.