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ASF GitHub Bot commented on FLINK-1319: --------------------------------------- Github user StephanEwen commented on the pull request: https://github.com/apache/flink/pull/729#issuecomment-105816818 Looks very nice, seems to have a good test coverage as well. How well does it work with bytecode generated by the Scala Compiler? > Add static code analysis for UDFs > --------------------------------- > > Key: FLINK-1319 > URL: https://issues.apache.org/jira/browse/FLINK-1319 > Project: Flink > Issue Type: New Feature > Components: Java API, Scala API > Reporter: Stephan Ewen > Assignee: Timo Walther > Priority: Minor > > Flink's Optimizer takes information that tells it for UDFs which fields of > the input elements are accessed, modified, or frwarded/copied. This > information frequently helps to reuse partitionings, sorts, etc. It may speed > up programs significantly, as it can frequently eliminate sorts and shuffles, > which are costly. > Right now, users can add lightweight annotations to UDFs to provide this > information (such as adding {{@ConstandFields("0->3, 1, 2->1")}}. > We worked with static code analysis of UDFs before, to determine this > information automatically. This is an incredible feature, as it "magically" > makes programs faster. > For record-at-a-time operations (Map, Reduce, FlatMap, Join, Cross), this > works surprisingly well in many cases. We used the "Soot" toolkit for the > static code analysis. Unfortunately, Soot is LGPL licensed and thus we did > not include any of the code so far. > I propose to add this functionality to Flink, in the form of a drop-in > addition, to work around the LGPL incompatibility with ALS 2.0. Users could > simply download a special "flink-code-analysis.jar" and drop it into the > "lib" folder to enable this functionality. We may even add a script to > "tools" that downloads that library automatically into the lib folder. This > should be legally fine, since we do not redistribute LGPL code and only > dynamically link it (the incompatibility with ASL 2.0 is mainly in the > patentability, if I remember correctly). > Prior work on this has been done by [~aljoscha] and [~skunert], which could > provide a code base to start with. > *Appendix* > Hompage to Soot static analysis toolkit: http://www.sable.mcgill.ca/soot/ > Papers on static analysis and for optimization: > http://stratosphere.eu/assets/papers/EnablingOperatorReorderingSCA_12.pdf and > http://stratosphere.eu/assets/papers/openingTheBlackBoxes_12.pdf > Quick introduction to the Optimizer: > http://stratosphere.eu/assets/papers/2014-VLDBJ_Stratosphere_Overview.pdf > (Section 6) > Optimizer for Iterations: > http://stratosphere.eu/assets/papers/spinningFastIterativeDataFlows_12.pdf > (Sections 4.3 and 5.3) -- This message was sent by Atlassian JIRA (v6.3.4#6332)