For us we typically leave a 500MB difference between the heap and the
container size. I think we can make this smaller, but we have not really
tried.
--Bobby
On 5/3/13 11:20 AM, "Karthik Kambatla" <ka...@cloudera.com> wrote:
>Hi
>
>While looking into MAPREDUCE-5207 (adding defaults for
>mapreduce.{map|reduce}.memory.mb), I was wondering how much headroom
>should
>be left on top of mapred.child.java.opts (or other similar JVM opts) for
>the container memory itself?
>
>Currently, mapred.child.java.opts (per mapred-default.xml) is set to 200
>MB
>by default. The default for mapreduce.{map|reduce}.memory.mb is 1024 in
>the
>code, which is significantly higher than the 200MB value.
>
>Do we need more than 100 MB for non-JVM memory per container? If so, does
>it make sense make that a config property in itself and the code to verify
>all 3 values are clear enough?
>
>Thanks
>Karthik
