What is a tracking branch

Question

Can someone explain a  tracking branch  as it applies to git   Here s the definition from git-scm com      A  tracking branch  in Git is a local   branch that is connected to a remote   branch  When you push and pull on that   branch  it automatically pushes and   pulls to the remote branch that it is   connected with       Use this if you always pull from the   same upstream branch into the new   branch  and if you don t want to use    git pull  explicitly    Unfortunately  being new to git and coming from SVN  that definition makes absolutely no sense to me   I m reading through  The Pragmatic Guide to Git   great book  by the way   and they seem to suggest that tracking branches are a good thing and that after creating your first remote  origin  in this case   you should set up your master branch to be a tracking branch  but it unfortunately doesn t cover why a tracking branch is a good thing or what benefits you get by setting up your master branch to be a tracking branch of your origin repository   Can someone please enlighten me  in English

User · Answer

tracking branch is nothing but a way to save us some typing.

If we track a branch, we do not have to always type git push origin <branch-name> or git pull origin <branch-name> or git fetch origin <branch-name> or git merge origin <branch-name>. given we named our remote origin, we can just use git push, git pull, git fetch,git merge, respectively.

We track a branch when we:

clone a repository using git clone
When we use git push -u origin <branch-name>. This -u make it a tracking branch.
When we use git branch -u origin/branch_name branch_name

User · Answer

This was how I added a tracking branch so I can pull from it into my new branch   git branch --set-upstream-to origin Development new-branch

User · Answer

TL DR  Remember  all git branches are themselves used for tracking the history of a set of files   Therefore  isn t every branch actually a  quot tracking branch quot   because that s what these branches are used for  to track the history of files over time   Thus we should probably be calling normal git  quot branches quot    quot tracking-branches quot   but we don t   Instead we shorten their name to just  quot branches quot   So that s partly why the term  quot tracking-branches quot  is so terribly confusing  to the uninitiated it can easily mean 2 different things  In git the term  quot Tracking-branch quot  is a short name for the more complete term   quot Remote-tracking-branch quot   It s probably better at first if you substitute the more formal terms until you get more comfortable with these concepts  Let s rephrase your question to this  What is a  quot Remote-tracking-branch  quot  The key word here is  Remote   so skip down to where you get confused and I ll describe what a Remote Tracking branch is and how it s used   To better understand git terminology  including branches and tracking  which can initially be very confusing  I think it s easiest if you first get crystal clear on what git is and the basic structure of how it works   Without a solid understand like this I promise you ll get lost in the many details  as git has lots of complexity   translation  lots of people use it for very important things   The following is an introduction overview  but you might find this excellent article also informative   WHAT GIT IS  AND WHAT IT S FOR A git repository is like a family photo album   It holds historical snapshots showing how things were in past times   A  quot snapshot quot  being a recording of something  at a given moment in time  A git repository is not limited to holding human family photos   It  rather can be used to record and organize anything that is evolving or changing over time  The basic idea is to create a book so we can easily look backwards in time   to compare past times  with now  or other moments in time  and to re-create the past    When you get mired down in the complexity and terminology  try to remember that a git repository is first and foremost  a repository of snapshots  and just like a photo album  it s used to both store and organize these snapshots   SNAPSHOTS AND TRACKING  tracked  - to follow a person or animal by looking for proof that they have been somewhere  dictionary cambridge org   In git   quot your project quot  refers to a directory tree of files  one or more  possibly organized into a tree structure using sub-directories   which you wish to keep a history of  Git  via a 3 step process  records a  quot snapshot quot  of your project s directory tree at a given moment in time  Each git snapshot of your project  is then organized by  quot links quot  pointing to previous snapshots of your project  One by one  link-by-link  we can look backwards in time to find any previous snapshot of you  or your heritage  For example  we can start with today s most recent snapshot of you  and then using a link  seek backwards in time  for a photo of you taken perhaps yesterday or last week  or when you were a baby  or even who your mother was  etc  This is refereed to as  quot tracking   in this example it is tracking your life  or seeing where you have left a footprint  and where you have come from   COMMITS A commit is similar to one page in your photo album with a single snapshot  in that its not just the snapshot contained there  but also has the associated meta information about that snapshot   It includes   an address or fixed place where we can find this commit  similar to its page number  one snapshot of your project  of your file directory tree  at a given moment in time  a caption or comment saying what the snapshot is of  or for  the date and time of that snapshot  who took the snapshot  and finally  one  or more  links backwards in time to previous  related snapshots like to yesterday s snapshot  or to our parent or parents   In other words  quot links quot  are similar to pointers to the page numbers of other  older photos of myself  or when I am born to my immediate parents   A commit is the most important part of a well organized photo album   THE FAMILY TREE OVER TIME  WITH BRANCHES AND MERGES Disambiguation    quot Tree quot  here refers not to a file directory tree  as used above  but rather to a family tree of related parent and child commits over time  The git family tree structure is modeled on our own  human family trees  In what follows to help understand links in a simple way  I ll refer to   a parent-commit as simply a  quot parent quot   and a child-commit as simply a  quot child quot  or  quot children quot  if plural   You should understand this instinctively  as it is based on the tree of life   A parent might have one or more children pointing back in time at them  and children always have one or more parents they point to   Thus all commits except brand new commits   you could say  quot juvenile commits quot    have one or more children pointing back at them   With no children are pointing to a parent  then this commit is only a  quot growing tip quot   or where the next child will be born from   With just one child pointing at a parent  this is just a simple  single parent  lt -- child relationship    Line diagram of a simple  single parent chain linking backwards in time   older       lt --link1-- Commit1  lt --link2-- Commit2  lt --link3-- Commit3  newest    BRANCHES  branch - A  quot branch quot  is an active line of development  The most recent commit on a branch is referred to as the tip of that branch  The tip of the branch is referenced by a branch head  which moves forward as additional development is done on the branch  A single Git repository can track an arbitrary number of branches  but your working tree is associated with just one of them  the  quot current quot  or  quot checked out quot  branch   and HEAD points to that branch    gitglossary   A git branch also refers to two things   a name given to a growing tip   an identifier   and the actual branch in the graph of links between commits   More than one child pointing --at a-- gt  parent  is what git calls  quot branching quot   NOTE   In reality any child  of any parent  weather first  second  or third  etc   can be seen as their own little branch  with their own growing tip   So a branch is not necessarily a long thing with many nodes  rather it is a little thing  created with just one or more commits from a given parent  The first child of a parent might be said to be part of that same branch  whereas the successive children of that parent are what are normally called  quot branches quot   In actuality  all children  not just the first  branch from it s parent  or you could say link  but I would argue that each link is actually the core part of a branch  Formally  a git  quot branch quot  is just a name  like  foo  for example  given to a specific growing tip of a family hierarchy   It s one type of what they call a  quot ref quot     Tags and remotes which I ll explain later are also refs    ref - A name that begins with refs   e g   refs heads master  that points to an object name or another ref  the latter is called a symbolic ref   For convenience  a ref can sometimes be abbreviated when used as an argument to a Git command  see gitrevisions 7  for details  Refs are stored in the repository  The ref namespace is hierarchical  Different subhierarchies are used for different purposes  e g  the refs heads  hierarchy is used to represent local branches   There are a few special-purpose refs that do not begin with refs   The most notable example is HEAD    gitglossary    You should take a look at the file tree inside your  git directory   It s where the structure of git is saved   So for example  if your name is Tom  then commits linked together that only include snapshots of you  might be the branch we name  quot Tom quot   So while you might think of a tree branch as all of it s wood  in git a branch is just a name given to it s growing tips  not to the whole stick of wood leading up to it  The special growing tip and it s branch which an arborist  a guy who prunes fruit trees  would call the  quot central leader quot  is what git calls  quot master quot   The master branch always exists  Line diagram of  Commit1 with 2 children  or what we call a git  quot branch quot                    parent      children                           -- Commit  lt -- Commit  lt -- Commit  Branch named  Tom                                                  v  older       lt -- Commit1  lt -- Commit                        Branch named  master        Remember  a link only points from child to parent  There is no link pointing the other way  i e  from old to new  that is from parent to child  So a parent-commit has no direct way to list it s children-commits  or in other words  what was derived from it   MERGING Children have one or more parents   With just one parent this is just a simple parent  lt -- child commit   With more than one parent this is what git calls  quot merging quot   Each child can point back to more than one parent at the same time  just as in having both a mother AND father  not just a mother    Line diagram of   Commit2 with 2 parents  or what we call a git  quot merge quot   i e  Procreation from multiple parents                   parents     child                  lt -- Commit                         v                             older       lt -- Commit1  lt -- Commit2     REMOTE This word is also used to mean 2 different things   a remote repository  and the local alias name for a remote repository  i e  a name which points using a URL to a remote repository    remote repository - A repository which is used to track the same project but resides somewhere else  To communicate with remotes  see fetch or push    gitglossary    The remote repository can even be another git repository on our own computer   Actually there are two URLS for each remote name  one for pushing  i e  uploading commits  and one for pulling  i e  downloading commits  from that remote git repository  A  quot remote quot  is a name  an identifier  which has an associated URL which points to a remote git repository    It s been described as an alias for a URL  although it s more than that   You can setup multiple remotes if you want to pull or push to multiple remote repositories  Though often you have just one  and it s default name is  quot origin quot   meaning the upstream origin from where you cloned    origin - The default upstream repository  Most projects have at least one upstream project which they track  By default origin is used for that purpose  New upstream updates will be fetched into remote-tracking branches named origin name-of-upstream-branch  which you can see using git branch -r    gitglossary   Origin represents where you cloned the repository from  That remote repository is called the  quot upstream quot  repository  and your cloned repository is called the  quot downstream quot  repository   upstream - In software development  upstream refers to a direction toward the original authors or maintainers of software that is distributed as source code wikipedia   upstream branch - The default branch that is merged into the branch in question  or the branch in question is rebased onto   It is configured via branch  remote and branch  merge  If the upstream branch of A is origin B sometimes we say  quot A is tracking origin B quot     gitglossary   This is because most of the water generally flows down to you  From time to time you might push some software back up to the upstream repository  so it can then flow down to all who have cloned it  REMOTE TRACKING BRANCH A remote-tracking-branch is first  just a branch name  like any other branch name  It points at a local growing tip  i e  a recent commit in your local git repository  But note that it effectively also points to the same commit in the remote repository that you cloned the commit from   remote-tracking branch - A ref that is used to follow changes from another repository  It typically looks like refs remotes foo bar  indicating that it tracks a branch named bar in a remote named foo   and matches the right-hand-side of a configured fetch refspec  A remote-tracking branch should not contain direct modifications or have local commits made to it    gitglossary   Say the remote you cloned just has 2 commits  like this  parent42  lt    child-of-4  and you clone it and now your local git repository has the same exact two commits  parent4  lt    child-of-4  Your remote tracking branch named origin now points to child-of-4  Now say that a commit is added to the remote  so it looks like this   parent42  lt    child-of-4  lt    new-baby   To update your local  downstream repository you ll need to fetch new-baby  and add it to your local git repository   Now your local remote-tracking-branch points to new-baby   You get the idea  the concept of a remote-tracking-branch is simply to keep track of what had previously been the tip of a remote branch that you care about   TRACKING IN ACTION First we begin tracking a file with git   Here are the basic commands involved with file tracking    mkdir mydir  amp  amp   cd mydir  amp  amp   git init               create a new git repository    git branch                                          this initially reports no branches                                                         IMHO this is a bug      git status -bs         -b   branch  -s   short      master branch is empty    No commits yet on master          touch foo                                           create a new file    vim foo                                             modify it  OPTIONAL      git add         foo  commit -m  your description     start tracking foo    git rm  --index foo  commit -m  your description     stop  tracking foo    git rm          foo  commit -m  your description     stop  tracking foo  amp  also delete foo  REMOTE TRACKING IN ACTION   git pull      Essentially does   get fetch  git merge      to update our clone  There is much more to learn about fetch  merge  etc  but this should get you off in the right direction I hope

User · Answer

The Pro Git book mentions      Tracking branches are local branches that have a direct relationship to a remote branch   Not exactly  The SO question  Having a hard time understanding git-fetch  includes      There s no such concept of local tracking branches  only remote tracking branches    So origin master is a remote tracking branch for master in the origin repo    But actually  once you establish an upstream branch relationship between    a local branch like master and a remote tracking branch like origin master   Then you can consider master as a local tracking branch  It tracks the remote tracking branch origin master which  in turn  tracks the master branch of the upstream repo origin

User · Answer

The ProGit book has a very good explanation   Tracking Branches  Checking out a local branch from a remote branch automatically creates what is called a tracking branch  Tracking branches are local branches that have a direct relationship to a remote branch  If you   re on a tracking branch and type git push  Git automatically knows which server and branch to push to  Also  running git pull while on one of these branches fetches all the remote references and then automatically merges in the corresponding remote branch   When you clone a repository  it generally automatically creates a master branch that tracks origin master  That   s why git push and git pull work out of the box with no other arguments  However  you can set up other tracking branches if you wish     ones that don   t track branches on origin and don   t track the master branch  The simple case is the example you just saw  running git checkout -b  branch   remotename   branch   If you have Git version 1 6 2 or later  you can also use the --track shorthand     git checkout --track origin serverfix Branch serverfix set up to track remote branch refs remotes origin serverfix  Switched to a new branch  serverfix    To set up a local branch with a different name than the remote branch  you can easily use the first version with a different local branch name     git checkout -b sf origin serverfix Branch sf set up to track remote branch refs remotes origin serverfix  Switched to a new branch  sf    Now  your local branch sf will automatically push to and pull from origin serverfix   BONUS  extra git status info  With a tracking branch  git status will tell you whether  how far behind your tracking branch you are - useful to remind you that you haven t pushed your changes yet  It looks like this     git status On branch master Your branch is ahead of  origin master  by 1 commit     use  git push  to publish your local commits    or    git status On branch dev Your branch and  origin dev  have diverged  and have 3 and 1 different commits each  respectively     use  git pull  to merge the remote branch into yours

User · Answer

Below are my personal learning notes on GIT tracking branches  hopefully it will be helpful for future visitors         Tracking branches and  git fetch

[git] What is a tracking branch?

Examples related to git

Examples related to version-control

Examples related to branch