mrmetrics.log collision on write

[Manhee Jo]

Hi all,

MR metrics log file ("/tmp/mrmetrics.log") is set by global configuration 
per datanode.
But there can be multiple mappers running on the datanode at the same time.
When multiple mappers write MR metrics to /tmp/mrmetrics.log,
how do they solve collition on write? Are there any arbitration mechanisms
to synchronize the write?
Thanks,
Manhee Jo