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https://issues.apache.org/jira/browse/FLINK-5718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15858314#comment-15858314
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ASF GitHub Bot commented on FLINK-5718:
---------------------------------------

Github user StephanEwen commented on a diff in the pull request:

    https://github.com/apache/flink/pull/3276#discussion_r100128721
  
    --- Diff: docs/setup/config.md ---
    @@ -86,7 +86,7 @@ The default fraction for managed memory can be adjusted 
using the `taskmanager.m
     
     - `taskmanager.memory.segment-size`: The size of memory buffers used by 
the memory manager and the network stack in bytes (DEFAULT: 32768 (= 32 
KiBytes)).
     
    -- `taskmanager.memory.preallocate`: Can be either of `true` or `false`. 
Specifies whether task managers should allocate all managed memory when 
starting up. (DEFAULT: false). When `taskmanager.memory.off-heap` is set to 
`true`, then it is advised that this configuration is also set to `true`.  If 
this configuration is set to `false` cleaning up of the allocated offheap 
memory happens only when the configured JVM parameter MaxDirectMemorySize is 
reached by triggering a full GC.
    +- `taskmanager.memory.preallocate`: Can be either of `true` or `false`. 
Specifies whether task managers should allocate all managed memory when 
starting up. (DEFAULT: false). When `taskmanager.memory.off-heap` is set to 
`true`, then it is advised that this configuration is also set to `true`.  If 
this configuration is set to `false` cleaning up of the allocated offheap 
memory happens only when the configured JVM parameter MaxDirectMemorySize is 
reached by triggering a full GC. **Note:** For streaming setups, we highly 
recommend to set this value to `false` as the core state backends currently do 
not use the managed memory.
    --- End diff --
    
    That would probably be good


> Handle JVM Fatal Exceptions in Tasks
> ------------------------------------
>
>                 Key: FLINK-5718
>                 URL: https://issues.apache.org/jira/browse/FLINK-5718
>             Project: Flink
>          Issue Type: Improvement
>          Components: Local Runtime
>            Reporter: Stephan Ewen
>            Assignee: Stephan Ewen
>
> The TaskManager catches and handles all types of exceptions right now (all 
> {{Throwables}}). The intention behind that is:
>   - Many {{Error}} subclasses are recoverable for the TaskManagers, such as 
> failure to load/link user code
>   - We want to give eager notifications to the JobManager in case something 
> in a task goes wrong.
> However, there are some exceptions which should probably simply terminate the 
> JVM, if caught in the task thread, because they may leave the JVM in a 
> dysfunctional limbo state:
>   - {{OutOfMemoryError}}
>   - {{InternalError}}
>   - {{UnknownError}}
>   - {{ZipError}}
> These are basically the subclasses of {{VirtualMachineError}}, except for 
> {{StackOverflowError}}, which is recoverable and usually recovered already by 
> the time the exception has been thrown and the stack unwound.



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