Branches are for Trees. How to develop software without them.

12
Branches are for trees. How to develop so4ware without them. Chris Bushell. September 2010.

description

Chris Bushell, ThoughtWorks, September 2010

Transcript of Branches are for Trees. How to develop software without them.

Page 1: Branches are for Trees. How to develop software without them.

Branches  are  for  trees.  How  to  develop  so4ware  without  them.  Chris  Bushell.  September  2010.  

Page 2: Branches are for Trees. How to develop software without them.

Feature  branching  

F1  

F2  

F3  

Merge  

Commit  

Release  

Page 3: Branches are for Trees. How to develop software without them.

What’s  the  problem?  

Page 4: Branches are for Trees. How to develop software without them.

Trunk  development  

Commit  

Release  

Page 5: Branches are for Trees. How to develop software without them.

Breaking  changes  

Page 6: Branches are for Trees. How to develop software without them.

Branch  by  abstracIon  1  –  Introduce  an  abstracIon  over  area  of  the  system  you  want  to  change  

3  –  Make  a  new  implementaIon  of  the  abstracIon  

2  –  Update  all  code  to  rely  on  the  abstracIon  

4  –  Remove  the  old  implementaIon  

5  –  Remove  the  abstracIon  if  it’s  inelegant  

Page 7: Branches are for Trees. How to develop software without them.

Cherry  picking  

Page 8: Branches are for Trees. How to develop software without them.

Toggles/flippers/flags/bits  

Page 9: Branches are for Trees. How to develop software without them.

Advantages  •   Decouples  code  deployment  from  feature  

•   No  need  to  roll  back  a  release,  just  disable  problemaIc  feature  

•   A/B  tesIng  

•   Private  betas  e.g.  turn  on  a  feature  for  5%  of  users  

•   Dark  launches  

•   ConInuous  deployment/delivery  

 

Page 10: Branches are for Trees. How to develop software without them.

Things  to  keep  in  mind…..  •   Complexity  and  overhead  explosion  if  toggles  aren’t  acIvely  decommissioned  

•   Don’t  overload  toggles  e.g.  enItlements  (totally  different  life  spans)  

•   Just  because  a  feature  is  dormant  doesn’t  mean  quality  is  not  as  important  

•   Avoid  coupling  features  e.g.  feature  b  can  only  be  enabled  if  feature  a  is  enabled      

Page 11: Branches are for Trees. How to develop software without them.

Conclusion  •   Branching  in  VCS  isn’t  bad    •   Long  lived  branches  in  VCS  are  bad  

•   Working  in  isolaIon  for  prolonged  periods  of  Ime  is  bad    

•   There’s  always  another  way,  it  just  might  require  some  careful  thought  and  design      

Page 12: Branches are for Trees. How to develop software without them.

References  •   hap://marInfowler.com/bliki/FeatureBranch.html    •   hap://paulhammant.com/blog/branch_by_abstracIon.html    •   hap://www.se-­‐radio.net/2008/09/episode-­‐109-­‐ebays-­‐architecture-­‐principles-­‐with-­‐randy-­‐shoup/    •   hap://velocityconference.blip.tv/file/2284377  (Flickr,  10+  releases  per  day)    •   hap://www.infoq.com/presentaIons/Feature-­‐Bits  

•   ImplemenIng  Lean  So4ware  Development:  From  Concept  To  Cash,  Mary  Poppendieck,  Tom  Poppendieck    


I saw the branches of the trees - BDI Group saw the branches of the trees bend down a touch to meet, the clover-blossoms in the grass rise up to kiss my feet, Here runs the highway

I saw the branches of the trees - BDI Group saw the branches of the trees bend down a touch to meet, the clover-blossoms in the grass rise up to kiss my feet, Here runs the highway

Pruning Mature Trees - ArboricultureCommon reasons for pruning are to remove dead branches, to improve form, and to reduce risk. Trees may also be pruned to increase light and air

Pruning Mature Trees - ArboricultureCommon reasons for pruning are to remove dead branches, to improve form, and to reduce risk. Trees may also be pruned to increase light and air

Pruning and Training Apple Trees by - Century Farm … and Training Apple Trees ... branches receive sunlight and gives good light distribution around the ... in structure of the two

Pruning and Training Apple Trees by - Century Farm … and Training Apple Trees ... branches receive sunlight and gives good light distribution around the ... in structure of the two

BRANCH PERFORMANCE. Branch Types Rural Branches Urban Branches Large Branches Medium Branches Small Branches.

BRANCH PERFORMANCE. Branch Types Rural Branches Urban Branches Large Branches Medium Branches Small Branches.

mtwade.commtwade.com/Mount_Wade_Baptist_Church/Adult_Bible… · Web view40 And ye shall take you on the first day the boughs of goodly trees, branches of palm trees, and the boughs

mtwade.commtwade.com/Mount_Wade_Baptist_Church/Adult_Bible… · Web view40 And ye shall take you on the first day the boughs of goodly trees, branches of palm trees, and the boughs

Developing a preventive pruning program: Young trees · tree and half of the branches on a 5– to 10-year-old tree are temporary. These branches are managed with reduction cuts to

Developing a preventive pruning program: Young trees · tree and half of the branches on a 5– to 10-year-old tree are temporary. These branches are managed with reduction cuts to

BJapanese eetle Killer - BonideON TREES AND SHRUBS Treat trees and shrubs as soon as insects emerge (usually late spring). Treat leaves, branches and tree trunks evenly, making sure

BJapanese eetle Killer - BonideON TREES AND SHRUBS Treat trees and shrubs as soon as insects emerge (usually late spring). Treat leaves, branches and tree trunks evenly, making sure

Emerald Ash Borer Management Options · trees planted along streets or in yard settings. Healthy trees have full crowns, elongating branches, and bark held tightly to the trunk/branches.

Emerald Ash Borer Management Options · trees planted along streets or in yard settings. Healthy trees have full crowns, elongating branches, and bark held tightly to the trunk/branches.

Handy Hints - Home - Whittlesea Council · trees may also require the main branches to be drilled/frilled and filled. Deciduous trees should only be treated when they are actively

Handy Hints - Home - Whittlesea Council · trees may also require the main branches to be drilled/frilled and filled. Deciduous trees should only be treated when they are actively

BRANCHES - files.credochs.com · BRANCHES The purpose of our parental Christian School is to educate our children to develop their individual potential and to acquire the knowledge,

BRANCHES - files.credochs.com · BRANCHES The purpose of our parental Christian School is to educate our children to develop their individual potential and to acquire the knowledge,

Index of Trees — Keys for Identifying Trees · 2008-08-11 · Trees have three main parts - the leaves, the trunk and the roots. The upper part of the tree with the branches is

Index of Trees — Keys for Identifying Trees · 2008-08-11 · Trees have three main parts - the leaves, the trunk and the roots. The upper part of the tree with the branches is

Multiway Trees. Trees with possibly more than two branches at each node are know as Multiway trees. 1. Orchards, Trees, and Binary Trees 2. Lexicographic.

Multiway Trees. Trees with possibly more than two branches at each node are know as Multiway trees. 1. Orchards, Trees, and Binary Trees 2. Lexicographic.

No Slide Title · 2018. 10. 12. · • Coronary collateral vessels develop in response to impairment of coronary blood flow • Collaterals develop between branches of occluded and

No Slide Title · 2018. 10. 12. · • Coronary collateral vessels develop in response to impairment of coronary blood flow • Collaterals develop between branches of occluded and

Tries. Multiway Trees Trees with possibly more than two branches at each node are know as Multiway trees. 1. Orchards, Trees, and Binary Trees 2. Lexicographic.

Tries. Multiway Trees Trees with possibly more than two branches at each node are know as Multiway trees. 1. Orchards, Trees, and Binary Trees 2. Lexicographic.

Short Course on Pruning Trees and Shrubs in the Landscape · Pruning – Step by Step 1. Assess 2. Remove dead, diseased and broken branches 3. Remove crossing branches 4. Remove

Short Course on Pruning Trees and Shrubs in the Landscape · Pruning – Step by Step 1. Assess 2. Remove dead, diseased and broken branches 3. Remove crossing branches 4. Remove

Induction of Decision Trees - Home - Springer · In summary, then, the systems described here develop decision trees for classifica- tion tasks. These trees are constructed beginning

Induction of Decision Trees - Home - Springer · In summary, then, the systems described here develop decision trees for classifica- tion tasks. These trees are constructed beginning

Living With Wildfire · almost always consist of living vegetation (trees, shrubs, grass and weeds) and dead plant material (dead trees, dried grass, fallen branches, pine needles,

Living With Wildfire · almost always consist of living vegetation (trees, shrubs, grass and weeds) and dead plant material (dead trees, dried grass, fallen branches, pine needles,

Home Policy Information insurance Policy booklet · • to trees or the cost of removing fallen trees or branches; • caused by tree felling or lopping operations; • to aerials

Home Policy Information insurance Policy booklet · • to trees or the cost of removing fallen trees or branches; • caused by tree felling or lopping operations; • to aerials

READY, SET, GO! · 2020-04-30 · trees. Remove ladder fuels, creating a separation between low-level vegetation and tree branches to keep fire from climbing up trees. Remove dead

READY, SET, GO! · 2020-04-30 · trees. Remove ladder fuels, creating a separation between low-level vegetation and tree branches to keep fire from climbing up trees. Remove dead

Landscaping in Florida with Fire in Mind - edis.ifas.ufl.edu · Martha Monroe and Alan Long2 1. ... Trim lower branches up to 10 feet on tall trees, remove vines from trees, and keep

Landscaping in Florida with Fire in Mind - edis.ifas.ufl.edu · Martha Monroe and Alan Long2 1. ... Trim lower branches up to 10 feet on tall trees, remove vines from trees, and keep