9. Build Release and Dependency Management

Question 1

why do we need build release and dependency management

Answer 1

1. all projects depend on other software
2. compiling dependencies may be slow and not completely automatable
3. enables caching of ‘oven ready’ components

Question 2

Type of dependencies

Answer 2

1. environmental
   - explicit
   explicitly documented in in configuration(needs to be known) eg. sdk version

• implicit
  cannot be checked by the dependency management system eg. system libraries

2. application

Question 3

Types of repositories

Answer 3

1. public release repositories
   - better for distribution to customers and for obtaining standard realise of 3rd party libraries
2. local
   - pre-public stable versions of components
   - hard to compile components
   - special internal versions of 3rd party compontents

Question 4

why do we need to specify dependencies

Answer 4

1. project almost always have transitive dependencies
2. dependencies may be cyclic
3. dependency resolution –> NP complete
4. different strategies used to find satisfactory combination of dependencies

Question 5

good practices

Answer 5

1. dependency resolution optimisation
   - under constrained specification may result in incompatible combinations
   - over constrained specification limits flexibility, require more effort to maintain
2. migrate to new release when available
3. do not rely on transitive dependencies

Question 6

type of release

Answer 6

1. composition
2. schedule/intent
   - snapshot
   - incremental

Question 7

release branching

Answer 7

1. allow team to prepare stable release
2. only allowed to fix bugs, merged back to main
3. new features to be developed in other branches

Question 8

types of API

Answer 8

private
published
public

Question 9

semantic versioning

Answer 9

format:

major. minor.incremental.[-tag]
eg. 4.0.3-SNAPSHOT

major: breaking change to published API
minor: non breaking feature addition
patch increase: non breaking bug fix changes
tags: release status

Question 10

deprecating

Answer 10

1. features left in place for compatibility reasons

2. removed from future releases

Question 11

documenting obsolete features

Answer 11

1. scope
2. release version containing new mechanism
3. schedule for when deprecated will be removed
4. explanation of why removed
5. description of how to change dependant codes

Question 12

migration plan includes

Answer 12

1. means to estimate duration of migration
   summary of know issues with new release
2. data migration include necessary backups and alterations
3. upgrade of dependencies of changed software
4. how to adapt existing source code to use new API