Continuous Integration vs. Nightly Build Charlie Berg [email_address]

What Is Continuous Integration (CI)? Martin Fowler - “...team integrates work frequently, usually each person integrates at least daily - leading to multiple integrations per day.” Verified by an automated build & test Results in significantly reduced integration problems; allows team to develop cohesive software more rapidly.” Key pillar of Agile Practices

Martin Fowler - “...team integrates work frequently, usually each person integrates at least daily - leading to multiple integrations per day.”

Verified by an automated build & test

Results in significantly reduced integration problems; allows team to develop cohesive software more rapidly.”

Key pillar of Agile Practices

Nightly Build (NB)‏ Steve McConnell - "daily build and smoke test" process. Every file is compiled, linked, and combined Program is then put through a "smoke test," - set of automated unit tests Benefits minimizes integration risk reduces the risk of low quality supports easier defect diagnosis

Steve McConnell -

"daily build and smoke test" process.

Every file is compiled, linked, and combined

Program is then put through a "smoke test," - set of automated unit tests

Benefits

minimizes integration risk

reduces the risk of low quality

supports easier defect diagnosis

What's the Diff? NB is periodic, run overnight when more time Less frequent, more resource-intensive CI is on demand, several times a day Theoretically for each check-in Is one better than the other?

NB is periodic, run overnight when more time

Less frequent, more resource-intensive

CI is on demand, several times a day

Theoretically for each check-in

Is one better than the other?

Some Discussion on Diffs Consensus is the difference is scale, i.e. How long it takes to run unit tests & the resource cost http://tinyurl.com/n6kzhh http://tinyurl.com/n9aubz The issue is about when is best to integrate... Is ASAP integration the best?

Consensus is the difference is scale, i.e. How long it takes to run unit tests & the resource cost

http://tinyurl.com/n6kzhh

http://tinyurl.com/n9aubz

The issue is about when is best to integrate...

Is ASAP integration the best?

Is ASAP Integration Best? Ultimately, ASAP Integration should happen on every checkin But... Eliminates use of code repository as backup of code-in-progress sandbox Requires that I integrate now , in the middle of development of my development task – disruption of flow The discussion is really about when to do QA

Ultimately, ASAP Integration should happen on every checkin

But...

Eliminates use of code repository as backup of code-in-progress sandbox

Requires that I integrate now , in the middle of development of my development task – disruption of flow

The discussion is really about when to do QA

QA To answer question of when , let's define what is QA QA = Verification & Validation Verification: testing that product implements what's in the spec Easily automated – unit tests Good candidate for either CI or NB

To answer question of when , let's define what is QA

QA = Verification & Validation

Verification: testing that product implements what's in the spec

Easily automated – unit tests

Good candidate for either CI or NB

QA Validation: testing that the product fulfill's customer's needs, regardless of what is in the spec. About use model Difficult to automate – how does a machine judge whether customer's needs are fulfilled regardless of any spec?

Validation: testing that the product fulfill's customer's needs, regardless of what is in the spec.

About use model

Difficult to automate – how does a machine judge whether customer's needs are fulfilled regardless of any spec?

The Real Issue... When should team: Perform verification? Perform validation? Reduce integration costs?

When should team:

Perform verification?

Perform validation?

Reduce integration costs?

Timing of Integration & Test Verification & Validation Verification Reduce Integration Risk Continuous Integration Nightly Build Release Build

Timing of Integration & Test CI Run “smoke” tests or as much verification as possible on every checkin Resource limited NB Run all verification nightly Release Build Run as often as QA can run validation testing Iterative Continuous Integration Nightly Build Release Build

CI

Run “smoke” tests or as much verification as possible on every checkin

Resource limited

NB

Run all verification nightly

Release Build

Run as often as QA can run validation testing

Iterative

Summary 3 Testing Requirements Verification Validation Reduce risk of integration Difference between CI & NB is available resources to run verification testing Release Testing required for validation

3 Testing Requirements

Verification

Validation

Reduce risk of integration

Difference between CI & NB is available resources to run verification testing

Release Testing required for validation

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