Glossary A

Access Control A set of functionality implemented as a proxy, providing more granular authentication and authorization rules for Subversion than can be implemented with Apache alone.

APR Subversion is built on a portability layer called APR (Apache Portable Runtime library). This means Subversion should work on any operating system that the Apache httpd server runs on: Windows, Linux, all flavors of BSD, Mac OS X, Netware and others.

Glossary B

Branch A branch is a copy of an existing original tree of directories and files. A branch always begins life as a copy of something, and evolves from there, generating its own history. Branches allow developers to make big changes without risking changes to previous work. Great for adding new features or starting new versions.

Glossary C

CentOS is a community-supported, free and open source operating system based on Red Hat Enterprise Linux. It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution. CentOS stands for Community ENTerprise Operating System.

Checkout Checking out a repository creates a copy of a desired branch on your local machine. This copy contains the latest revision of the repository that you specify.

Commit A Commit of a file means the changes you have made on your local copy gets updated into the repository. Once a commit is made, users can see the latest version of that particular file after they do an "Update".

Conflict A conflict occurs when two or more users change the same lines in a file. While Subversion is often able to reconcile such changes, usually the two sets of changes need to be manually editted.

CVS Concurrent Versions System is a popular open source code versioning system. CVS, like most source code versioning systems, is designed to run as a central server to which multiple CVS clients connect using a CVS protocol over TCP.

Glossary d

DAV Subversion makes repositories available to end-users through customizable URLs. For example, the "nomad" repository might be located at:
This directory location is defined in the Apache config file, within the Location Directive, like so:

<Location /nomad>
    DAV svn
    SVNPath /home/svn/nomad
    SVNSpecialURI .special
See the entry about the Location Directive for more information.

Glossary d

Glossary d

Glossary g

GUID Globally Unique Identifier. Each node is assigned a GUID when added to a Replication Group. The nodes identify each other by their GUIDs.

Glossary h

High Availability provides continuous hot backup, while making failover and disaster recovery automatic and transparent for both developers and administrators. One or more backup servers can be placed on the same local area network (LAN) as the primary server, or located remotely over a wide area network (WAN).

Hook A hook is a program triggered by some repository event, such as the creation of a new revision or the modification of an unversioned property. A hook is handed enough information to tell what that event is, what targets it is operating on and the username of the person who triggered the event.

Glossary i

Glossary j
Glossary k

Glossary l

LDAP Lightweight Directory Access Protocol, is an Internet protocol that email and other programs use to look up information from a server. LDAP is currently used as a service for managing user credentials and access control.

Location Directive The Apache configuration that controls how Subversion is a exposed to end-users.

Lock A Lock refers to a mechanism which a user asks for the exclusive right to make changes to a repository file.

Glossary m

Merging Merging refers to the joining together of changes made on one branch into the trunk or vice versa another branch, which may also be the trunk.

Glossary n

Glossary o

Owl A fan of Sheffield Wednesday Football Club.

Glossary p

Port 9890 The default port used for the uberSVN portal.

Port 9880 The default port used for uberSVN's Subversion server. This port is configurable during installation, or through the General settings on the Admin tab of the uberSVN portal.

prefs.xml The preferences file contains configuration information. Replication Group configuration is stored in the Membership Configuration Registry. The files are specific to each node. The preference files are located in (svn or cvs)-replicator/config.

Provider Id Another name for the GUID.

Glossary q

Glossary r

Repository At the heart of Subversion is the Repository. It is a centralized system to store and share data. The repository stores information in the form of a set of trees and branches, a hierarchy of directories and files. Any number of clients can connect to the repository and read or write to these files.

Repository Browser Allows a user to work directory with a repository without having to work on a working copy. This is where the repository browser comes in. It is identical to an explorer window with the icons, address bar to type in the repository URL name displayed. It also features commands like Copy, Move and Delete.

Repository URL's

Revision Numbers are used by Subversion to note whenever a change has been made in a repository. Although the number provides no information about the version history it can be correlated with a specific time in history. The --revision (-r) option can also accept as input date specifiers wrapped in curly braces ({ and }). Subversion accepts the standard ISO-8601 date and time formats, plus a few others. Here are some examples. (Remember to use quotes around any date that contains spaces.)

$ svn checkout -r {2006-02-17}
$ svn checkout -r {15:30}
$ svn checkout -r {15:30:00.200000}
$ svn checkout -r {"2006-02-17 15:30"}
$ svn checkout -r {"2006-02-17 15:30 +0230"}
$ svn checkout -r {2006-02-17T15:30}

RPO Recovery Point Objective. In disaster recovery the RPO is the time before a system failure at . An RPO of 2 hours means that, in the event of a failure, the system would be brought back to the point that is no more than 2 hours before the failure ocurred.

RTO Recovery Time Objective. In disaster recovery the RTO is the time in which the system should be recovered from a failure. With an RTO of 2 hours, the system should be recovered no more than two hours after the failure occured. High Availability offers an RTO of 0, meaning that recovery is immediate.

Glossary s

SCM Software Configuration Management is the field dedicated to tracking and controlling changes in the software. WANdisco provides products that support two popular SCM solutions; Subversion and CVS.

Subversion An open-source revision control system, which aims to be a compelling replacement for CVS.

SVN Abbreviation used for Subversion.

Glossary t

Tagging Tagging is basically placing a label on each file, no matter what revision number it has. This can be done either to a working copy or to the repository itself; the effects being the same.

TortoiseSVN TortoiseSVN is a client for using Subversion on Windows. It's free software that modifies the Windows shell, providing seamless integration of Subversion commands into the Windows explorer. Download it from: Read Introducing TortoiseSVN.

Glossary u

Glossary v

Glossary w

WANdisco Wide Area Network Distributed computing. WANdisco is a leading provider of distributed software development solutions. By using WANdisco's unique replication technology, software development occurs anywhere without the constraints associated with far-flung distribution.

WebDAV Web-based Distributed Authoring and Versioning, or WebDAV is a set of extensions to the Hypertext Transfer Protocol (HTTP) that allows computer-users to edit and manage files collaboratively on remote web servers.

Working copy A working copy is an up-to-date copy of file(s) downloaded from the repository onto a local machine. To download a working copy of a file you would use the Checkout command.

Glossary x

Glossary y

Yeturu Aahlad Dr Aahlad is Wandisco's chief scientist and is recognised as a authority on distributed computing in which he currently holds 3 patents.

Prior to WANdisco, Dr. Aahlad served as the distributed systems architect for iPlanet (Sun/Netscape Alliance) Application Server. At Netscape, Dr. Aahlad joined the elite team in charge of creating a new server platform based on the CORBA distributed object framework.

Glossary z