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Copyright IBM Corp. 2003 1 - 1

Course materials may not be reproduced in whole or in part without the prior written permission of IBM.

Module 1Getting Started

1

IBM Software Group

Essentials of Rational ClearCase

Module 1: Getting Started

Topics

Objectives............................................................................................................ 1-2Software Development and Change...................................................................... 1-3Typical Developer ClearCase Workflow................................................................ 1-9Typical Workflow: Setting Up Your Workspace................................................... 1-10Types of Views................................................................................................... 1-17Creating a Dynamic View in the File Browser...................................................... 1-22Starting a Dynamic View from CLI ...................................................................... 1-26Mounting a VOB for Dynamic Views .................................................................. 1-29Accessing Online Help ....................................................................................... 1-32

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1 - 2 Copyright IBM Corp. 2003


Objectives

2

Define software configuration management (SCM)

Explain how ClearCase implements SCM

Explain ClearCase roles

Define basic ClearCase terminology and concepts

Explain the typical developer workflow in ClearCase

Set up your ClearCase workspace

Access ClearCase Help

Upon completing this module, you should be able to:

Objectives

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Module 1 - Getting Started



Software Development and Change

3

Software Development and Change

Software development involves change

A defect to be fixed

An existing function to be enhanced

A new feature to be added

A new platform to support

A customer-driven special project

Internationalization

In software development, change is constant. Change requests come from a variety ofsources. If not managed, change can overwhelm a project.

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Change Causes Developers Pain

4

Change Causes Developers Pain Working in isolation, you cant see code changes made

by team members

You cant work in parallel on files that a co-worker ismodifying

You frequently lose time and have to redo work because oflost defects or overwritten code

You have trouble determining which versions of the codeyou should be working on

You have difficulty answering your managers questionsabout project status

You dont know who on the team is working on what

You have no idea which versions of files went into a build

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Software Configuration Management (SCM)

5

Software Configuration Management (SCM)

SCM is about

managing change

to software.

Brian White, Software Configuration

Management Strategies and

Rational ClearCase (2000)

Software Configuration Management (SCM) is the software engineering discipline thatdeals with managing change to software.

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Software Configuration Management (cont.)

6

Software Configuration Management (cont.) A successful SCM effort ensures:

Safety

Stability

Control

Auditability

Reproducibility

Traceability

Scalability

A successful SCM effort ensures:

Safety Ability to recover from failure and to prevent unauthorized use. Stability Ability to create stable, user-controlled workspaces.

Control Ability to enforce appropriate project-specific workflow controls. Auditability Ability to know what is included in a particular build. Reproducibility Ability to mark milestones and reconstruct configurations. Traceablity Ability to identify and reconstruct particular versions of a software

product. Scalability Ability to support small and large projects as well as distributed

development.

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ClearCase Implements SCM

7

ClearCase Implements SCM Version control

Version all types of

files and directories

Build management

Ensure the integrity of

all software elements

Accurately reproduceevery release

Trace and reproduce

builds

Workspace management

Work in parallel with

other developers

Process control

Record and report

actions, history, and

milestones

Customize process

ClearCase provides tool support in the following areas:

Version control It provides a repository for versioned objects and associatedmetadata, called a versioned object base, or VOB.

Workspace management It allows you to create workspaces that give projectmembers access to a projects shared versioned objects. These independentworkspaces, or views, enable parallel development.

Build management It provides version selection for building software, and recordkeeping, which allows you to accurately reproduce any build.

Process control ClearCase provides tools for implementing site-specific policies.

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ClearCase Roles

8

ClearCase Roles ClearCase developer

Set up workspace

Make changes

Integrate changes

Update workspace

ClearCase configurationmanager

Write CM plan

Design developmentenvironment

Establish CM Policies

Assign and schedule work

Monitor project status

ClearCase integrator

Create integrationworkspace

Create baselines

Build components

ClearCase administrator

Set up hardwareenvironment

Implement developmentenvironment

Maintain hardware anddevelopmentenvironments

There are a number of tasks that must be performed in a ClearCase environment. Rolesdo not correspond to individuals. In some organizations, one person may fill more thanone role, for example, ClearCase administrator and configuration manager orconfiguration manager and integrator.

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Typical Developer ClearCase Workflow

9

Typical Developer ClearCase Workflow

In this course, you learn to perform the tasks outlined in the typical developerworkflow. As a developer, you will find yourself performing these tasks over and overagain.

The first three modules of the course teach you to perform these tasks. The labs at theend of each module allow you to practice.

This workflow assumes the use of dynamic views. You learn more about dynamic viewslater in this module.

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Typical Workflow: Setting Up Your Workspace

10

Typical Workflow: Setting Up Your Workspace

In the remainder of this module, you learn the concepts and skills you need to set upyour own workspaces in ClearCase.

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What Is a Versioned Object Base (VOB)?

11

What Is a Versioned Object Base (VOB)?

Stores files, directories, andmetadata

Stores version-controlled data

Displays its contents as filesin a file system

Stores anything that can berepresented as a file or directory

Can be replicated in two or more sites

A permanent, read-only data repository that:

A Versioned Object Base (VOB) is a repository that stores versioned-controlled files,directories, and metadata. ClearCase displays VOB contents as files in a file system.

VOBs can reside on the following systems:

Windows XP Windows 2000 Windows NT UNIX, including Red Hat Linux

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Projects and VOBs

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Projects and VOBs A project can span more than one VOB

Multiple projects can share common VOBs

The ClearCase administrator or configuration manager generally sets up VOBs for aproject. A project can have one or multiple VOBs. Multiple projects can share the sameVOBs. Administrators can symbolically link VOBs together so that they appear to theuser as a single directory tree.

There is no single way to organize VOBs for a project. Many organizations set up VOBsto correspond with their system architecture. For example, a project that is building anew publishing software application might have the following system components andcorresponding VOBs:

Database Word processor File manager

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What Is an Element?

13

A file or a directory, under source control,

stored in a ClearCase VOB

Can be any object that can be stored in a native

file system, including:

Source files

Directories

Binary files

Object libraries

Documents

What Is an Element?

An element is any file or directory that is under source control in ClearCase, whichcould include source files, directories, documents, binary files, and data libraries.

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What Is a Version?

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An element consists of a set of versions, organized

into a version tree

Each version represents

one revision of a file

under source control

Versions are displayed

in a workspace or view

What Is a Version?

Each time you check in a file or directory that is under source control, ClearCasecreates a new version of it. The versions represent the history of the element's evolutionthrough each stage of its development. You can access any previous version of anelement.

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What Is a View?

15

What Is a View? A ClearCase mechanism that allows users access

to versions of elements in VOBs

An isolated workspace for a user or a group

Enables users to work in parallel

A viewis the ClearCase mechanism that allows you to access versions of elementsstored in a VOB from standard development tools. When you create a view, you set upyour private workspace where you can work on elements that are under source control.You can decide which VOBs or elements within VOBs you want work with. And, you

can decide which versions of the elements you want to access.

You may have multiple views, which allows you to manage different tasks by using adifferent view for each task. For example, you may have views for:

New development Bug fixes Porting activities Ad hoc configuration

A view may access multiple VOBs.

The view name is known as a view_tag.

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What Is a Configuration Specification?

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What Is a Configuration Specification? For each view, a set of ordered rules used to

select at most one version of each element

Determine which versions of an element are

visible in the view

Each view has its own configuration specification, a set of ordered rules that determinewhich version of VOB elements are visible in a view.

Configuration specification is often abbreviated to config spec.

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Types of Views

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Types of Views

Except in ClearCase LT, when you create a view, you must choose whether it is adynamic or a snapshot view. A dynamic view uses the ClearCase multiversion filesystem (MVFS) to arrange VOB data into a directory tree; a snapshot view loads

elements onto your computer.

Dynamic views use the ClearCase multiversion file system (MVFS) to provideimmediate, transparent access to files and directories stored in VOBs.

Connected to shared storage Work on virtual copy of elements in the VOB (MVFS) Dynamic changes as new work is shared Always up-to-date Provides buildauditing

Snapshot views copy files and directories from VOBs to a directory on your computer.

Can work disconnected from shared storage

Work on local copy of elements in the VOB (native file system) Static user controls when work is shared Must be updated manually Provides optimal build performance

For more information about dynamic and snapshot views, see the Developing SoftwarewithClearCase manual.

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Which Type of View Should I Use?

18

Which Type of View Should I Use?

You are using Win 9X,

Win ME, or ClearCase

LT, which do not

support dynamic views

You want to work

disconnected from the

network

You do not need build

avoidance

You want to access

elements in repositories

without copying them to

your computer

You want the view to

reflect changes made by

other team members atall times

Your project uses build

auditing

SnapshotDynamic

Both types of views can exist on your computer at the same time.

In a dynamic view, you automatically see changes made by other team members. In asnapshot view, you must periodically update the view to stay current.

Snapshot views allow you to work disconnected from the network.

For more information on build auditing, refer to the Rational ClearCase BuildingSoftware manual.

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Structure of a Dynamic View

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Structure of a Dynamic View

Every dynamic view has a view storage directory, which ClearCase uses to keep trackof which versions are checked out to your view and to store view-private files (checkedout files or files not under source control in ClearCase).

The views config spec selects the versions of elements from the VOB to display.ClearCase uses the MVFS to arrange VOB data into a directory tree. The elementversions you see displayed in the virtual file system are read-only until checked out.Upon checkout, a read/write copy becomes available in the view storage directory.

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Structure of a Snapshot View

20

Structure of a Snapshot View

A snapshot view creates a view root directory into which it loads (copies) files anddirectories from VOBs. The view root directory is often on a local computer.

By default, ClearCase locates the view storage of a snapshot view under the view root

directory.The config spec of a snapshot view includes load rules that determine which VOBelements are loaded into the view. The files are read-only until checked out. Uponcheckout, a read/write copy is available locally.

Periodically, a snapshot view must be updated to keep current with changes to datawithin the VOB.

You learn more about creating and working with snapshot views later in this course.

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Intro to ClearCase File Browser

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Intro to ClearCase File Browser

File and directory information

Operationalbuttons

Currentworking

directory

To open the File Browser:

From the CLI, type xclearcase.

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Creating a Dynamic View in the File Browser

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Creating a Dynamic View in the File Browser

1

To create a view, clickView > Create.

You cannot start xclearcase unless you already have a view created. Therefore, youmust create your first view from the CLI.

Before creating a view:

Your UNIX umask setting at the time you create your view determines how accessible itwill be to others:

umask Effect on Your View002 Members of your UNIX group can create and modify view-

private data. Other users have read-only access.

007 Members of your UNIX group can create and modify view-private data. Other users are completely excluded.

022 Only you can write view-private data.Everyone else has read-only access.

077 A completely private view.Only the view creator can read or write view-private data.

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Creating a Dynamic View in the File Browser (cont.)

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4

Click Advanced Options tospecify the location of theview storage directory.

2

Select DynamicView.

3

Choose a viewname (or view-tag).

It is a good idea to name views so that they indicate owners and purpose, for example:

pat_r2dev_view alex_r1_bugfix

It is also a good idea to distinguish between dynamic and snapshot view storage areasby using a consistent extension for their directories: xxx.vws for dynamic views andxxx.sv for snapshot views.

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24

Creating a Dynamic View in the File Browser (cont.)5

Confirm the view information, and thenclick Continue.

The Confirm window displays information about the view that is being created. ClickContinue to finish creating the view.

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Creating a Dynamic View from CLI

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Creating a Dynamic View from CLImkview -tag dynamic-view-tagdynamic-view-storage-pname

% cleartool mkview -tag pat_r2_dev/home/pat/pat_r2_dev.vws

Created View.

Host-local path: saturn:/home/pat/pat_r2_dev.vwsGlobal path:/net/saturn/home/pat_r2_dev.vws

It has the following rights:User : pat : rwxGroup : user : r-x

Other : : r-x

Must exist Must NOT exist

In most cases, slides in this course contain abbreviated command syntax. For completecommand syntax, see the ClearCase Reference Manual.

This syntax applies to dynamic views only.

The .vws file extension is a recommended convention; it stands for view workingstorage. You can name the view storage anything you choose. However, it is a goodidea to name view (and VOB) storage areas something that easily identifies them.

If the global path is accessible throughout the network, you can use your view onanother workstation.

View permissions are determined by the users umask value at the time when the viewis created.

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Starting a Dynamic View from CLI

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Starting a Dynamic View from CLI

Starts a dynamic view

Sets the specified view to your current workingview

Spawns a shell process that is set to thedynamic view

setview view-tag

% cleartool setview pat_r2_dev

%

You can nest views by setting a dynamic view while in a dynamic view.

% cleartool setview alex_r2_dev

%

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Starting a Dynamic View from the File Browser

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Starting a Dynamic View from the File Browser1

Click View > Set.

2

Select the view tag.

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Displaying Your Current View

28

Displaying Your Current View

% cleartool pwvWorking directory view: ** NONE **Set view: pat_r2_dev_view

pwv [-short] [-wdview | -setview | -root]

cleartool pwv displays the view-tag that is working (filtering) the current VOB directory.If the current working directory is not in a VOB, it displays **NONE**. It also displaysthe view-tag set in the current shell.

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Mounting a VOB for Dynamic Views

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Mounting a VOB for Dynamic Views

The mount command activates a VOB for use on

the local workstation

You access a VOB through its unique tag name

Public VOBs are mounted on boot up and with the

mount all command

mount [-options mount options] {vob-tag| -all}

% cleartool mount /vobs/Hardware

A file system must be mounted or activated before you can use it.

VOBs are activated automatically on the host where they were created.

A private VOB is intended to be activated by a single user; a public VOB is intended tobe activated by more than one user.

The difference between a private and a public VOB is in how the VOB is mounted:

When the VOB-tag is private, you must mount the VOB explicitly, by supplying itsVOB-tag. To mount a VOB, use the cleartool mount command.

When the VOB-tag is public, you can mount the VOB explicitly, as with a privateVOB. In addition, you can mount all public VOBs in the network region at once,using the cleartool mount command with the -all option. You can add thiscommand to a script that mounts all public VOBs each time you start ClearCase.

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Accessing the VOB in the File System

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Accessing the VOB in the File System The VOB-tag or the VOB mount point is the full

pathname with which users access VOBs

VOB-tags are regular native operating system

directories

Mount point through which allmounted VOBs can be accessed

All mounted VOBs arevisible under /vobs

/vobs

/VobA/VobB/VobC

The path to VobA is /vobs/VobA.

Examples:

% ls /vobs/VobA

bin lost+found src

% ls /vobs/VobB

common lost+found include

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Why Is the VOB-tag Directory Empty?

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Why Is the VOB-tag Directory Empty? Directories beneath the VOB-tag are inaccessible

until you

Mount the VOB

Set into a dynamic view

Example:% cd /vobs/Hardware% ls

%% cleartool mount /vobs/Hardware

% cleartool setview pat_r2_dev_view% lsbin lost+found src

To see a VOB in a view, mount the VOB and set into a dynamic view. If a view is notset, the VOB appears to be empty.

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Accessing Online Help

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Accessing Online Help

Access ClearCase

Help from the CLI

or from the

File Browser

Use thecommon UNIXman pagecommand toview thereferencemanual

Use the Help option toview command usage

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Accessing Online Help (cont.)

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You can access Help from the File Browser main menu.

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34


Online Manuals

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Module Review

35

What is SCM?

How does ClearCase help you manage change tosoftware?

What tasks are involved in setting up yourworkspace?

What is a VOB? Element? Version? View?

How do you access particular versions of elements

in a ClearCase VOB? What is the difference between a snapshot view and

a dynamic view?

How do you access online Help in ClearCase?

Module Review

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Module Lab

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In this lab, you will:

Launch ClearCase GUI

Create a dynamic view

Mount a VOB

Module Lab

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