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https://issues.apache.org/jira/browse/FLINK-32577?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Yunhong Zheng updated FLINK-32577:
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Description: This issue is a sub-issue of FLINK-18356. (was: This issue is
a sub-issue of FLINK-18356.
When I run mvn verify for flink table-planner in azure CI and my own machine.
I found that the heap memory and non-heap memory of JVM are stable and within
the normal range. However, the total memory usage ({*}RES{*}) of the fork
process is very high, as shown in the following figure(PID : 2958793 and
2958794):
!image-2023-07-11-19-28-52-851.png|width=537,height=245!
I try to delve deeper into the specific memory allocation of these two
processes:
{code:java}
pmap -p 2958793 {code}
I found that there are a lot of memory fragmentation here with a size close to
*64MB* (>200 memory fragmentation):
!image-2023-07-11-19-35-54-530.png|width=237,height=413!
Based on past experience, this issue is likely to trigger the classic problem
of the incorrect memory fragmentation manage by *glibc of JDK8.* So we
downloaded *libjemalloc* and added the environment variable:
{code:java}
export LD_PRELOAD=${JAVA_HOME}/lib/amd64/libjemalloc.so.2{code}
After that, the overall memory of the fork process has become stable and meets
expectations (5GB):
!image-2023-07-11-19-41-18-626.png|width=488,height=208!
!image-2023-07-11-19-41-37-105.png|width=228,height=287!
The solution to this problem requires modifying the CI execution Docker image
[Docker image|[https://github.com/flink-ci/flink-ci-docker],] replacing
*glibc* with *libjemalloc* like FLINK-19125， cc [~chesnay] :{*}{{*}}
{code:java}
apt-get -y install libjemalloc-dev
ENV LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libjemalloc.so {code}
I have opened a new Jira (FLINK-32577) to track and fix this issue. cc
[~mapohl] [~jark].
)
> Avoid memory fragmentation when running CI for flink-table-planner module
> -------------------------------------------------------------------------
>
> Key: FLINK-32577
> URL: https://issues.apache.org/jira/browse/FLINK-32577
> Project: Flink
> Issue Type: Improvement
> Components: Build System / CI, Table SQL / Planner
> Affects Versions: 1.18.0
> Reporter: Yunhong Zheng
> Priority: Major
> Fix For: 1.18.0
>
>
> This issue is a sub-issue of FLINK-18356.
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