Task failed to report status exception

[Jonathan Herzig]

Hi,

I'm running jaql over a cluster of 6 machines.

When i run my jobs on small data it runs smoothly.

However, when i use larger data (~4G) the following occurs:

I can see that alot of tasks which have been completed, go back to
"pending" state.
When this happens i get exceptions that look like:

"Task attempt_201103161639_0002_m_000000_0 failed to report status for
607 seconds. Killing!"

Most of the time the cluster gets stuck ater a while , apperantly from
memory loss, and should be restarted.

What can possibly be wrong?
Are there any parameters i should change?

Thanks,
Jonathan