4.4: CMDB Flashcards
The CMDB and Configuration Items
The Configuration Management Database is a series of tables and fields that contain all of the Configuration Items (CIs) controlled by your company, as well as their attributes and relationships.
Access to the CMDB tables and underlying data requires certain permissions, such as the following roles:
* asset
* itil
* itil_admin
* cmdb_read
Configuration Items
can be tangible or intangible devices or applications in the CMDB such as firewalls, computers, email services, and services.
*Computers
*Devices on the network
*Applications *Services
The Configuration Application provides
core functionality for the Configuration Management Database (CMDB), including modules for hardware and other configuration items. This functionality is part of the CMDB plugin, which is activated in a base install .
The CMDB provides
a logical model of your company infrastructure by identifying, controlling, maintaining, and verifying the configuration items (CIs) that exist .
A configuration item
is any component that needs to be managed in order to deliver services. CIs typically include services and their underlying components, such as business applications and hardware. However, be aware that the term “services” continues to evolve and is often overused. This can complicate conversations where references are made to “services”.
Three key CMDB tables
*Base Configuration Item [cmdb],
*Configuration Item [cmdb_ci ] which contains CI data,
*CI Relationship [cmdb_ rel_ci] which contains CI relationship data.
ServiceNow ‘s CMDB
in contrast to a static list, not only tracks the CIs within your platform, but al so the relationships between those items. Over time as the number of CIs grow , performance and heal t h of t he CMDB can be impact ed. Use t he CMDB Dat a Manager t ool t o creat e, publi sh, and manage CI policies t o help maint ain t he CMDB in an efficient and operat ional st ate.
CMDB use in ITSM Processes
*Incident Management - an infrastructure
component broke in
our data center.
*Change Management - We need to change
something in our Data Center.
*Problem Management - We have identified a defect in our
infrastructure.
*Request Management - I would like to have new software loaded on my computer.
The Configuration Management Database (CMDB)
is a repository of information related to all of the components of an information system. Although repositories similar to CMDBs have been used for years in IT, the origin of the CMDB stems from the Information Technology Infrastructure Library (ITIL). CMDBs help monitor and discover what system components are needed for effective and efficient business processes and IT service management.
All service management processes relate to and involve the CMDB. For example: someone calls with an issue, and you want to do a root cause analysis, the CMDB gives you insights to effectively troubleshoot. 193
NOTE: These are examples of CI class/tables
but each CI table is unique in the CMDB hierarchy. To fully underst and the CMDB table structure you need to underst and the hierarchical struct ure of the CMDB tables/schema.
CMBD Benefits
A high percent age of incident s are caused by failed changes. An accurate, up-to-date CMDB helps IT teams to:
* Locate failed changes and associated Incidents
*Facilitate impact analysis of proposed changes t o reduce or eliminate downtime
*Assess problem trends pertaining to specific CIs
*Efficiently manage incidents affecting CIs and serv ice delivery
CMDB Workspace
is a central place for working with the CMDB. Use CMDB Workspace to search and explore the CMDB, examine health and recent activity, and access various CMDB dashboards and tool s to support tasks in your organization.
*Plugins: CMDB CSDM Support, CSDM Activation.194
Configuration Items: Dependency View
DV provide an interactive graphical interface to visualize relationships between configuration items. 195
A ServiceNow service (application service or business service)
is work or goods t hat are support ed by an IT infrast ruct ure. For example, delivering emai l serv ice t o an employee can requi re serv ices such as emai l serv ers, w eb serv ers, and t he w ork t o configure t he user’ s account . The dependency v iew can help you see relat ionships bet ween Ci s in your infrast ructure.
In t he example prov ided, yo u can see business serv ices (Bond Trading and SAP Payroll ) t hat need access t o dat abases t hat t hen al so requi re t he nyc oracle clust er. If somet hing in t hi s map becom es unav ailable (due t o an out age, a syst em change, et c.), business serv ices such as SAP Payrol l could be impacted. 195
A Dependency View s map has one starting point,
called the root CI or root node of t he map. The root CIis surrounded by a darker frame t hat repaint s i t self w it h a pul sing effect draw ing t he at t ention t o t he root CI. The maps can show bot h upst ream and dow nstream dependencies for t he root CI. By defaul t , t he Dependency View s map di splays 3 lev els, bot h upst ream and dow nstream relat ionships. Adm inistrators can configure t he number of lev els di splayed. The map collapses and expands clust ers t o make t hem easier t o v iew . By defaul t , clust ers are collapsed. 195
In a Dependency Views map, map indicators indicate if
a CI has any active, pending issues. You can investigate the tasks that are connected to a CI to get more details. When yo u ret urn t o t he map from anot her form, t he syst em rest ores t he last map v iewed, using t he defaul t fi l t er and layout set t ings. When yo u click t he map icon on a CI record or on a t ask record t hat ident i fies a CI, t he map opens.
Many of t he relat ionships in t he map are creat ed t hrough t he di scov ery process. You can al so creat e, define, and delet e CI relat ionships in t he map. You can di splay t he map from di fferent perspect iv es and open specific records t hat relat e t o configuration i t em s. The syst em refreshes t he map aut omat ically t o reflect changes to the CMDB. 195
Dependency View: Map Icons
Icons: View lists of active problem, incident, or
change records for this CI
*Active Incident *Active Problems *Affected CIs for a task
Dependency views
also indicate the status of configuration items and allow access to the CI ‘s related alerts, incidents, problems, changes, and services.
* In a Dependency View , icons and glyphs indicate whether a CI has an active, pending issue. You can investigate the tasks that are connected to a configuration item to get more details. The map collapses and expands clusters to make them easier to view . Dependency view s indicate the status of its CIs, and allows access to CI related alerts, incidents, problems, changes, and services.
* Understanding the dependencies and other relationships among configuration items will enhance the operational delivery of incident , change, and problem management processes.
CI Class Manager
Use the CI Class Manager as a central location to explore the CMDB class hierarchy, CI table definitions, and class CIs.
*Alt hough a syst em adm ini st rator may not int eract w ith t he CMDB on a regular basi s, i t i s important t o underst and t he hierarchy of CI classes. In t he ev ent a CI needs t o be added manuall y, underst anding how t o nav igate t he hierarchy can prev ent a CI get t ing added t o an incorrect class t able.
*The CI Class Manager di splays t he ent i re CMDB class hierarchy in a t ree -v iew fo rmat, consolidating class defini tions into a cent ral locat ion. It let s you di splay met adat a information for a class, such as reconciliat ion rules, mandatory and recommended fields, and audi t t emplates. You can al so select a specific class t o v iew , t o modify, or t o ext end i t s defini t ion t o creat e a deriv ed class. For each class, you can di rect ly access CMDB Heal t h set t ings, ident i fication and reconciliat ion rules, orphan scorecard, and cert i ficat e t emplat e, defined for t he class. 197
CI Class Manager - Basic Info
Displays details for the selected class, such as the di splay and table name, descript ion, and class icon. You can edit some of the class definitions while you are prevented from editing some details such as the table name.
Role required: i t i l for reading, and i t i l_admin and personal ize_dict ionary for wri ting.
CI Class Manager -Attributes
Di splays table at t ributes (columns). You can edi t those at t ributes and add new ones.
Role requi red: personal ize_dict ionary and i t i l_admin for edi t ing, and personal ize_dict ionary and i t i l for reading 198
CI Class Manager Attributes Tabs
- The All t ab includes al l at tributes, including t hose t hat have been derived and/or added for t he CI Class.
- The Derived tab show s only attribut es derived from parent classes. 3. The Added t ab show only attributes t hat have been created specifically for the CI Class.
CI Class Manager Suggested Relationships
Use the CI
Relationship Editor to create
configuration item relationships.
*CI Relationship Editor is accessed from t he Related Items toolbar on a configuration item form .
*The CI record where the editor was launched is designated as the base CI. You can select one or more items to include in the relationship. Depending on the selected relationship type, the base CI can become the parent CI or the child CI in a new relationship.
*ServiceNow relationship rules use separate tables to define the relationships between specific CI base cl asses and dependent cl asses. When you extend a table in the CMDB, this table also inherits relationships from the table it is extending. You can create a new relationship rule in Al l > Configuration > Relationships > Suggested Relationships. 200
Configuration Item Form pozri obr 201
nic som tu nedala zo str 201
Common Service Data Model (CSDM)
The CSDM is a CMDB-based framework that identifies where to place data for the products you are using.
*CS – Common Ser vi ce A st andard and shared set of serv ice-relat ed defini tions across our product s and plat form t hat w il l enable and support t rue serv ice lev el report ing.
*DM – Data Model A CMDB Framew ork across our products and plat form t hat w il l enable and support mul tiple configurat ion st rategies.
The CSDM
is a set of terms and definitions that can be used with all ServiceNow products on the Now Platform. CSDM definitions enable service reporting and provide prescriptive guidelines for service modeling within t he CMDB. You can use t he CSDM as a blueprint t o map your IT services t o ServiceNow . Following t he CSDM framework ensures that the data hat your Serv iceNow application requi res maps correct ly t o t he appropriate CMDB t ables.202
Use t he CSDM to
- Show you how t o do a specific act iv i ty.
- Li st t he in-scope and out -of -scope act iv ities.
- Det ail s t he t ables and configurat ion i t em s (CIs) associat ed w it h t he use case.
- Describes t he benefi t (v alue propo sition) o f t he use case.
*Track asset s t hrough t heir li fe-cycle t ransi t ions. 202
CSDM: What it is
- Standard terms and definitions * Best Practice for CMDB Data Modeling and Data Management
- Out of the box CMDB core tables * Guidance on service modeling * Recommended mappings
CSDM: What is it NOT
- Not a process or implementation guide for ITSM, SPM, APM, EM, or Other products
- Not a set of reports * Not code to install * Not a SKU or product to buy * Not an automatic fix for past implementations
CSDM: What’s in it for you
- Consistently modeled service offerings enable: o Better understanding of service costs
o More accurate reporting - Consistent use of service across applications; reduction of duplication and confusion
- Less overhead when maintaining services
- Some products have a dependency on CSDM tables being populated
Where do I find CSDM in the Now Platform?
The CSDM is part of the Now Plat form out of t he box. Type CSDM in t he Applicat ion Nav igator t o learn more. 203
ServiceNow
Discovery*
scans the network to inventory devices and applications and updates the CMDB with the results for each unique type of hardware and software. *ServiceNow Discovery is available as a separat e subscript ion.
ServiceNow Service Mapping
(Top-down discovery) augments the CMDB with IT relationships and dependencies between CIs to model the IT components that comprise a Service. 204
Discovery
Discovery uses ServiceNow ’s MID (Management , Instrumentation, and Discovery) server, a
light weight jav a process t hat can run on a cust omer’ s Li nux o r W i ndows serv er, l ocated i n a dat a cent er, o r ho st ed i n a publi c cloud. The MID serv er can al so be communi cat ed t hrough a P ro xy serv er, i f requi red. I t i s t he MID serv er’ s j ob t o gat her i nfo rmatio n about dev i ces and appli cat i ons and ret urn resul t s back t o t he i nst ance fo r processi ng. Thi s al l t ak es pl ace dur i ng Di scov ery. The Di scov ery product engages a “ ho r i z ontal” met hod o f uncov eri ng dev i ces on t he net w o rk.
Di scov ery f i nds dev i ces on your net w o rk and t he impo rtant at tributes o f t ho se dev i ces (operat i ng syst em , so f t ware, mem ory, et c. ). I t est abli shes relat io nshi ps bet w een appli cat i ons and dev i ces and bet w een appli cat i ons t hat communicat e w it h each o t her. These relat i onships are v i sual iz ed i n t he Dependency View er. Typi call y, I T depar tment s creat e and mai nt ai n an i nv ent o ry t hat t reat s dev i ces and appli cat i ons as st andal one, i ndependent obj ect s . Connect io ns bet w een t he dev i ces and appli cat i ons are no t i ncluded. Thi s i s usuall y referred t o as ho r i z ontal di scovery. Thi s met hod does no t address t he biggest chall enge fo r I T depar tment s , w hich i s underst anding t he connect i on and dependenci es bet w een each obj ect . That i s w here Serv i ce Mappi ng comes i nt o pl ay.
204
Service Mapping
An appli cat io n serv ice i s a set o f i nt erco nnect ed appli cati ons and ho st s w hich are co nf i gured t o o f fer a serv i ce t o t he organi z ati on. Appli cat ion serv i ces can be i nt ernal , li ke an o rgani z atio n em ai l syst em o r cust omer-faci ng, li ke an o rgani zatio n w ebsi te. Fo r example, creat i ng f i nanci al repo rts t hrough a w eb-based appli cat ion requi res a comput er, w eb serv er, appl i cat io n serv er, dat abases, m i ddl eware, and net w ork i nf rastructure. These appli cat i ons and ho st s are al l co nf i gured t o o f fer t he serv i ce o f f i nanci al repo r t ing.
Service Mapping maps service-specific dependencies, based on the devices and applications that are used to deliver a serv ice. This method is referred to as top-down mapping. The top -down mapping helps you immediately see the impact of a problematic object on the rest of the application service operation. This top-down approach overlays service maps onto existing configuration data to connect CIs underlying a given service, making the CMDB service aware. For example, the loss of disk drives may take a database down, which affects the requisition service the HR department uses to order equipment for new employees.
ServiceNow Serv ice Mapping discovers and models the relationships and dependencies between discovered CIs and automatically populates this information into the CMDB. 204
Knowledge Check
Which modules can you use to create a new table?
- Tables
- Tables & Columns
Knowledge Check
Which elevated role is required to modify access control rules?
security_admin
Knowledge Check
What is a CI?
- Configuration Item
- Can be tangible (hardware, software, servers, etc.) or intangible (services, email, etc.)
Knowledge Check
A parent class that is not an extension of another table is called what?
Base table
Knowledge Check
In what order are access controls evaluated?
Table-level: most specific to most general then field-level: most specific to most general
Knowledge Check
What are the three key tables in the CMDB?
- cmdb
- cmdb_ci
- cmdb_rel_c
