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https://issues.apache.org/jira/browse/MNG-7509?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17564494#comment-17564494
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Xiong Luyao commented on MNG-7509:
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Further more, if we add 'export MAVEN_OPTS="-Xms1g -Xmx1g”’ for this project
build to limit the max heap size. Before change, it will throw OOM exception,
but it works well after change.
!image-2022-07-09-10-29-46-216.png|width=340!
!image-2022-07-09-10-29-51-456.png|width=341!
> Huge memory cost when parent pom widely used in a big project for
> dependencyManagement
> --------------------------------------------------------------------------------------
>
> Key: MNG-7509
> URL: https://issues.apache.org/jira/browse/MNG-7509
> Project: Maven
> Issue Type: Improvement
> Components: Performance
> Reporter: Xiong Luyao
> Priority: Major
> Attachments: image-2022-07-09-09-37-53-823.png,
> image-2022-07-09-09-38-26-354.png, image-2022-07-09-10-27-12-668.png,
> image-2022-07-09-10-27-56-437.png, image-2022-07-09-10-28-05-706.png,
> image-2022-07-09-10-28-22-864.png, image-2022-07-09-10-28-35-341.png,
> image-2022-07-09-10-28-40-612.png, image-2022-07-09-10-29-04-045.png,
> image-2022-07-09-10-29-15-822.png, image-2022-07-09-10-29-21-991.png,
> image-2022-07-09-10-29-46-216.png, image-2022-07-09-10-29-51-456.png
>
>
> When maven try to resolve dependency relationship, it will create many
> objects of dependency / artifact. Even the dependency/artifact content is
> totally same, but just in different models. It cost huge memory if there is a
> big dependencyManagement parent pom in each dependencies of the project.
>
> Here is a real case. As below picture, there is over 3000 business domain
> libraries, each library may rely on several other libraries among them. So
> the library which didn’t rely on each other will be built first and the
> library only relies on the built libraries will be built, until all the
> libraries have been built. In this way, we use a parent pom to maintain the
> version of these 3000+ libraries version and make each library introduce it.
> So that it can keep all the libraries are built from same base.
> But it costs huge memory in above ways to built libraries. And even the
> libraries have been released, if the project which contains a lot of above
> libraries, it also cost huge memory when building project.
>
> !image-2022-07-09-09-37-53-823.png|width=493,height=226!
>
> Here is a thread dump when building a real project with above libraries. The
> top 5 objects are all related to org.eclipse.aether.graph.Dependency.
> !image-2022-07-09-09-38-26-354.png|width=510,height=199!
>
>
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