Flink CDC Issue Import created FLINK-34831:
----------------------------------------------
Summary: [FLINK-CDC-BASE] Reorder dependency flink-table-runtime
in pom.xml to avoid dependency conflict.
Key: FLINK-34831
URL: https://issues.apache.org/jira/browse/FLINK-34831
Project: Flink
Issue Type: Improvement
Components: Flink CDC
Reporter: Flink CDC Issue Import
### Search before asking
- [X] I searched in the
[issues|https://github.com/ververica/flink-cdc-connectors/issues] and found
nothing similar.
### Motivation
flink-cdc-base declares flink-table-runtime as its direct dependency. There are
two transitive dependencies org.codehaus.janino:commons-compiler and
org.codehaus.janino:janino in the dependency tree as listed below. They are
introduced by flink-table-planner_2.12.
```
[INFO] com.ververica:flink-cdc-base:jar:3.0-SNAPSHOT
[INFO] +- org.apache.flink:flink-table-planner_2.12:jar:1.18.0:test
[INFO] | +- org.codehaus.janino:commons-compiler:jar:3.1.10:test
[INFO] | +- org.codehaus.janino:janino:jar:3.1.10:test
[INFO] +- org.apache.flink:flink-table-runtime:jar:1.18.0:test
```
Some duplicate classes in flink-table-planner are also in commons-compiler and
janino as listed below.
```
org.codehaus.commons.compiler.lang.ClassLoaders$SubresourceGetter
org.codehaus.commons.compiler.Location
org.codehaus.commons.compiler.util.LineAndColumnTracker$1
org.codehaus.commons.compiler.AbstractCompilerFactory
...
org.codehaus.janino.util.ClassFile$CodeAttribute
org.codehaus.janino.Java$ArrayAccessExpression
org.codehaus.janino.util.ClassFile$AnnotationDefaultAttribute
org.codehaus.janino.Java$TryStatement$LocalVariab
...
```
The problem is that the two transitive dependencies are ahead of
flink-table-runtime in the dependency tree, thus ahead of flink-table-runtime
in the classpath. When multiple JAR files contain the same class, the class
loader will load the first occurrence it finds based on the classpath order.
This means the classloader will **select classes in the transitive dependencies
rather than direcly declared flink-table-runtime**.
### Solution
Change the order of flink-table-runtime and flink-table-planner_2.12 so that
flink-table-runtime appears ahead of flink-table-planner_2.12 in classpath. In
this way, flink-table-runtime is used as it's meant to be.
### Alternatives
_No response_
### Anything else?
_No response_
### Are you willing to submit a PR?
- [X] I'm willing to submit a PR!
---------------- Imported from GitHub ----------------
Url: https://github.com/apache/flink-cdc/issues/2753
Created by: [HappyHacker123|https://github.com/HappyHacker123]
Labels: enhancement,
Created at: Sun Nov 26 17:00:07 CST 2023
State: open
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