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https://issues.apache.org/jira/browse/FLINK-1005?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14056678#comment-14056678
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ASF GitHub Bot commented on FLINK-1005:
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Github user rmetzger commented on the pull request:
https://github.com/apache/incubator-flink/pull/66#issuecomment-48526517
Very nice. This is very helpful for new users and reduces frustration when
trying out the system.
Once its merged, I'll run some benchmarks on the cluster to better
understand the performance implications.
> Add different mutable-object modes to runtime
> ---------------------------------------------
>
> Key: FLINK-1005
> URL: https://issues.apache.org/jira/browse/FLINK-1005
> Project: Flink
> Issue Type: Improvement
> Components: Local Runtime
> Affects Versions: 0.6-incubating
> Reporter: Stephan Ewen
> Assignee: Stephan Ewen
> Fix For: 0.6-incubating
>
>
> Currently, the runtime works strictly with mutable objects. That means that
> as few objects as possible (typically one or two) are reused for the data
> records all the time. Objects are cloned/restored, though, at various places
> to ensure that the contents is fresh at every call.
> The rational behind this was to reduce pressure on the garbage collector. In
> fact, you can run programs where no garbage collection happens (if the UDFs
> are written to reuse objects as well).
> It can, however, lead to bugs in not-carefully written user code.
> I propose to add two modes to the runtime:
> - No-object-reuse (default) mode. New objects for every record. Safe but
> potentially slower.
> - Object-reusing mode - All objects are reused, without backup copies.. The
> UDFs must be careful to not keep any objects as state or not to modify the
> objects,
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