Archiving artifacts in Jenkins - Time & Space Complexity

Time Complexity: Archiving artifacts

O(n)

Understanding Time Complexity

When Jenkins archives artifacts, it saves files from a build for later use. Understanding how the time to archive grows helps us plan for bigger projects.

We want to know: how does archiving time change as the number of files or their size increases?

Scenario Under Consideration

Analyze the time complexity of the following Jenkins pipeline snippet.

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        // build steps here
      }
    }
    stage('Archive') {
      steps {
        archiveArtifacts artifacts: '**/target/*.jar', fingerprint: true
      }
    }
  }
}
    

This code archives all .jar files found under any target folder after the build finishes.

Identify Repeating Operations

Look for repeated actions that affect time.

• Primary operation: Scanning the workspace to find matching files and copying each file to the archive storage.
• How many times: Once per file found matching the pattern; each file is processed individually.

How Execution Grows With Input

As the number of files grows, the time to archive grows too.

Input Size (n files)	Approx. Operations
10	About 10 file scans and copies
100	About 100 file scans and copies
1000	About 1000 file scans and copies

Pattern observation: The time grows roughly in direct proportion to the number of files.

Final Time Complexity

Time Complexity: O(n)

This means if you double the number of files, the archiving time roughly doubles too.

Common Mistake

[X] Wrong: "Archiving time stays the same no matter how many files there are."

[OK] Correct: Each file must be found and copied, so more files mean more work and more time.

Interview Connect

Knowing how archiving scales helps you understand build pipelines better. It shows you how tasks grow with project size, a useful skill in real DevOps work.

Self-Check

"What if we changed the archive pattern to include subfolders with many files? How would the time complexity change?"

Practice

1. What is the main purpose of using archiveArtifacts in a Jenkins pipeline?

easy

A. To delete old build files automatically

B. To save build output files for later use or sharing

C. To trigger another build job

D. To send email notifications after a build

Solution

1. Step 1: Understand the role of archiveArtifacts

   This command is used to save files generated by a build so they can be accessed later.

2. Step 2: Compare with other options

   Deleting files, triggering builds, or sending emails are different Jenkins features, not related to archiving artifacts.

3. Final Answer:

   To save build output files for later use or sharing -> Option B

4. Quick Check:

   Archiving = Saving build files [OK]

Hint: Archiving means saving build files for future use [OK]

Common Mistakes:

• Confusing archiving with deleting files
• Thinking it triggers other jobs
• Assuming it sends notifications

2. Which of the following is the correct syntax to archive all .jar files in a Jenkins pipeline script?

easy

A. archiveArtifacts '*.jar'

B. archiveArtifacts '*.jar;'

C. archiveArtifacts '*.jar' {}

D. archiveArtifacts '*.jar'()

Solution

1. Step 1: Recall the syntax of archiveArtifacts

   The correct syntax uses the command followed by the file pattern in quotes without extra characters.

2. Step 2: Identify incorrect syntax

   Options with semicolon, braces, or parentheses after the pattern are invalid in Jenkins pipeline syntax.

3. Final Answer:

   archiveArtifacts '*.jar' -> Option A

4. Quick Check:

   Correct syntax = archiveArtifacts 'pattern' [OK]

Hint: Use single quotes and no extra symbols after pattern [OK]

Common Mistakes:

• Adding semicolons inside the pattern string
• Using braces or parentheses incorrectly
• Missing quotes around the pattern

3. Given this Jenkins pipeline snippet:

stage('Build') {
  steps {
    sh 'echo Hello > output.txt'
    archiveArtifacts 'output.txt'
  }
}

What will Jenkins do after this stage completes?

medium

A. Send output.txt as an email attachment

B. Delete the file output.txt immediately

C. Fail the build because output.txt is not found

D. Save the file output.txt as a build artifact

Solution

1. Step 1: Understand the shell command

   The command creates a file named output.txt with the text 'Hello'.

2. Step 2: Analyze archiveArtifacts usage

   This command archives the specified file so it is saved with the build for later access.

3. Final Answer:

   Save the file output.txt as a build artifact -> Option D

4. Quick Check:

   archiveArtifacts saves files [OK]

Hint: archiveArtifacts saves files created in the build [OK]

Common Mistakes:

• Assuming the file is deleted after archiving
• Thinking the build fails if file exists
• Confusing archiving with emailing files

4. You wrote this Jenkins pipeline snippet:

archiveArtifacts '*.log'

But no files are archived after the build. What is the most likely reason?

medium

A. No .log files were created in the workspace

B. The syntax of archiveArtifacts is incorrect

C. Jenkins does not support archiving .log files

D. The build failed before reaching the archive step

Solution

1. Step 1: Check the file pattern and workspace

   If no .log files exist in the workspace, nothing will be archived.

2. Step 2: Verify syntax and Jenkins support

   The syntax is correct and Jenkins supports archiving any file type.

3. Step 3: Consider build status

   If the build failed before this step, archiving wouldn't run, but the question implies the step ran.

4. Final Answer:

   No .log files were created in the workspace -> Option A

5. Quick Check:

   Files must exist to be archived [OK]

Hint: Check if files exist before archiving [OK]

Common Mistakes:

• Assuming Jenkins can't archive certain file types
• Blaming syntax without checking files
• Ignoring build step execution order

5. You want to archive all .jar files in the build/libs folder and also keep the build logs named build.log. Which archiveArtifacts usage is correct?

hard

A. archiveArtifacts 'build/libs/*.jar', build.log

B. archiveArtifacts 'build/libs/*.jar build.log'

C. archiveArtifacts artifacts: 'build/libs/*.jar, build.log'

D. archiveArtifacts artifacts: 'build/libs/*.jar', 'build.log'

Solution

1. Step 1: Understand multiple file patterns in archiveArtifacts

   To archive multiple patterns, use the named parameter artifacts with a comma-separated string.

2. Step 2: Analyze each option

   archiveArtifacts 'build/libs/*.jar', build.log passes two positional arguments (invalid), archiveArtifacts 'build/libs/*.jar build.log' lacks comma separator, archiveArtifacts artifacts: 'build/libs/*.jar', 'build.log' has invalid syntax with two strings.

3. Final Answer:

   archiveArtifacts artifacts: 'build/libs/*.jar, build.log' -> Option C

4. Quick Check:

   Use artifacts: 'pattern1, pattern2' for multiple files [OK]

Hint: Use artifacts: 'pattern1, pattern2' to archive multiple files [OK]

Common Mistakes:

• Omitting the artifacts: parameter
• Separating patterns without commas
• Passing multiple strings instead of one