ShadowJar runs extremely slow compared to fatJar

[StFS]

Shadow Version

2.0.2

Gradle Version

4.3.1

Expected Behavior

shadowJar should be able to create a jar file in roughly the same time as my previous fatJar task.

Actual Behavior

shadowJar takes 15,5 hourse to run while fatJar finishes in ~4 minutes. The resulting jar file is around 150mb in size. shadowJar does eventually finish (I left it running last night and it finished as I said previously in more than 15 hours).

Gradle Build Script(s)

The fat jar part:

    task fatJar(type: Jar) {
        manifest manifestTemplate
        zip64 true
        baseName = getProjectFullName() + '-all'
        destinationDir = file("${buildDir}/distributions")
        from { configurations.runtime.collect { it.isDirectory() ? it : zipTree(it) } } {
            exclude 'META-INF/*'
        }
        with jar
    }

The shadowJar part:

    apply plugin: 'com.github.johnrengelman.plugin-shadow'

    shadowJar {
        mainClassName = "com.my.client.ClientClass"
        zip64 true
    }

The project is a multi-project so the specific sub-project that I'm trying to build as a fatJar/shadowJar has dependencies on both other sub-projects as well as external JAR libraries.

Content of Shadow JAR (jar tf <jar file> - post link to GIST if too long)

Don't have one, deleted the one that got generated in 15 hours but it did look like it was similar in size as the one generated by the fatJar task.

What can cause such a huge slowdown?

[johnrengelman]

You haven't provided enough information to make any type of guess why you would experiencing that magnitude of slowness. In every other case and the reason why I wrote Shadow in the first place was because it was faster than using the zipTree method as it doesn't incur I/O costs by writing to the disk.

I'm going to close this issue as it doesn't contain any particulars.

[michel-zededa]

Hi,

i'm actually seeing the same issue, but not sure what to provide for debugging?

[victorbr]

I believe I'm reproducing this using the following build.gradle file with Gradle 4.7 (no source files necessary)

buildscript {
    repositories {
        mavenCentral()
    }
}

plugins {
    id 'com.github.johnrengelman.plugin-shadow' version '2.0.3'
}

apply plugin: 'java'

repositories {
    mavenCentral()
}

dependencies {
    compile "com.hubspot.dropwizard:dropwizard-guice:1.0.6.0"
}

The problem disappears when I replace the plugins section by

    dependencies {
        classpath 'com.github.jengelman.gradle.plugins:shadow:2.0.3'
    }

(inside buildscript) and

apply plugin: 'com.github.johnrengelman.shadow'

[johnrengelman]

@victorbr - you should be using the 2nd plugin. The first one is for shadowing Gradle plugins and configures shadow to relocate all dependencies. Dropwizard has a lot of transitive dependencies so that will obviously take longer.

[johnrengelman]

This could also be related to
#364 and
#374

There is a 2.0.4-SNAPSHOT that has some changes to address this that you could try.

[madorb]

runs INCREDIBLY, unusably, slowly for me as well. macos, gradle 4.9, shadow 2.0.3

[johnrengelman]

@madorb have you tried version 2.0.4 that has some fixes for potential causes?

[sg-rs]

Same here. FatJar takes 40 seconds. Shadow does not complete in 15 Minutes

[sg-rs]

For an unexplainable reason using the gradlew command insted of gradle works.

This works (40 seconds):
./gradlew shadowJar

This not (15 Minutes, not completing the build):
gradle shadowJar

[sg-rs]

Maybe this is relevant:

gradlew used Gradle 7.4.2

gradle used Gradle 7.3.3