cmdbs: above and beyond…

CMDBs: Above and Beyond…Sarah NadiCS 446 – Nov. 26th, 2009

Overview

•This work is in collaboration with CA Labs Canada.

•This is part of the work done in the Software Architecture Group (SWAG).

CMDBs: Above and Beyond

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Outline• Importance of proper IT management.

• What is a Configuration Management Database (CMDB)?

• Use cases of a CMDB.

• What are root cause analysis and change impact analysis?

• Example work done on root cause analysis and change impact analysis.


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Enterprise IT Management• Information Technology (IT) systems are the basis of most

business services today.

• When something goes wrong with an IT system, companies face financial losses.

• Therefore, Enterprise IT Management (EITM) has been lately gaining a lot of interest.

• Reactively, IT analysts should be able to quickly locate the underlying cause of a problem (Root Cause Analysis).

• Proactively, IT analysts should be able to identify the impacts of changes to the system to prevent unforeseen problems (Change Impact Analysis).

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Configuration Management Database• A Configuration Management Database (CMDB) stores the

information about the different components of an IT system. It contains details about the attributes and history of each Configuration Item (CI), details of the relationships between CIs, their problem and change history.

• A configuration item (CI) is any component of an IT infrastructure. It can be software, hardware, services etc.

• Usually, business critical components are included as CIs in the CMDB.

• The information in a CMDB provides a basis for root cause analysis and change impact analysis.

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Configuration Management Databases (CMDB) (The big picture)

Service Z

Service YForwards

IT System

Service X

Provides

Uses

IT Analyst

Calls


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Has

Information

CMDBProvides More Details


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Configuration Items (CIs)

CMDB Relationships

Knowledge contained in a CMDB• Hardware, networks, locations, etc.

• Software, SLA, versioning information.

• Reporting structures, contacts, organization.

• Dependencies between components.

• Incident and Problem reports.

• History of changes made, by who, when, why, etc.

• Gateway to logs and diagnostics.


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Seven use cases of a CMDB [1]

• What can the data in a CMDB be used for?

▫ Change Impact Analysis.

▫ Change Governance.

▫ Root Cause Analysis.

▫ Auditing and Compliance.

▫ Resource Optimization.

▫ Services Mapping.

▫ Services Performance Planning.


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Root Cause Analysis

Analyst


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Root Cause Analysis

• A fault is a design flaw or malfunction that causes a failure of one or more CIs or IT services.

• A failure is the loss of ability to operate to specification, or to deliver the required output.

• An incident is an observed event that is not part of the standard operation of a service and that causes, or may cause, an interruption to, or a reduction in, the quality of that service.

• Root cause analysis tries to map an incident to its underlying fault.


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Change Impact Analysis

•“What if” analysis. Find impact of a proposed change.

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Dealing with a Changing World


Change Impact Analysis• A change set is the set of CIs that need to be changed for a

change to be correctly implemented with no side effects.

• Unplanned changes can cause unexpected problems in related CIs Identifying the correct change set is very important.

• Accurate change impact analysis proactively prevents future incidents.


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Importance of root cause analysis & change impact analysis• Reactively, IT analysts should be able to quickly locate the

underlying cause of a problem (root cause analysis).

• Proactively, IT analysts should be able to identify the impacts of changes to the system to prevent unforeseen problems (change impact analysis).

• Root cause analysis and change impact analysis are, therefore, important IT management activities that prevent costly IT outages.


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Challenges• Identifying the information needed to perform root cause

analysis and change impact analysis.

• Finding the best way to model this information.

• Providing practical and useful solutions.


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Our Proposed Solution: DRACA• A Decision Support framework for Root Cause Analysis

and Change Impact Analysis.

• Given the CI involved in an incident, DRACA provides a list of ranked CIs who are suspect root causes (root cause analysis).

• Given an initial CI to change, DRACA provides a list of ranked CIs who should be changed as well (change impact analysis).


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Info. needed for root cause analysis•Existing dependencies in the CMDB.

•Previous incident reports, problem reports, and change reports.

•Calendar information.

•CI Change Times.


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DRACA’s Root Causes Analysis Process


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Root cause matrix

•Rij is the probability that i is the root cause of the incident in j


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Info. needed for change impact analysis •Historical change sets

▫CIs that have changed simultaneously in the past are likely to change again together in the future.

▫Understanding previous change sets can help identify future ones.


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DRACA’S Change Impact Analysis Process


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The DRACA Prototype Tool


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Empirical Work• Tested our technique on industrial data from CA’s Global

Information Systems (GIS) team that manage CA’s internal network and services.

• We used 3 years worth of data to test our prediction model.

• Our results were promising and we were able to correctly predict a large percentage of the change sets.


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Summary• Proper IT management is very important to minimize IT

systems’ disruptions.

• A CMDB supports IT management by tracking business critical CIs.

• Root cause analysis and change impact analysis are two important process in IT management.

• Root cause analysis involves finding the original cause of a problem.

• Change impact analysis involves finding the set of CIs that might be affected by a proposed change.


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Questions/Comments ?


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References

[1] Messineo, David A & Ryder, Macolm. Why Implement a Configuration Management Database (CMDB)? Seven Fundamental Use Cases. CA White Paper, 2008.]


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cmdbs: above and beyond…

Documents

problem root cause analysis

change impact analysiswhat

underlying cause

root cause analysisa

change governance

proposed change

management eitm

business services