`gget` downloads results twice

[GoogleCodeExporter]

When using `gget` to download results of all tasks in a session, and
the session uses `RetryableTask` to wrap application execution, all
results are systematically being downloaded twice. Here an example:

    (gc3pie)$ gget -s 5_Params -A
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_129#1'
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_128#1'
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_127#1'
    [...]
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_138#1'
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_129#1'
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_128#1'
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_127#1'
    [...]
    A snapshot of job results was successfully retrieved in '.../5_Params/tricellular_junction_138#1'

This issue has been first reported by Tinri Aegerter on the
`gcelljunction` script, but it likely applies to any session-based
script that uses `RetryableTask` to wrap an application execution.

Original issue reported on code.google.com by riccardo.murri@gmail.com on 15 Apr 2014 at 10:34

[GoogleCodeExporter]

I guess the most general solution would be to keep a record of the
`output_directory` already processed by `gget`, and process each one
only once. IOW, if two tasks share an output directory, only one of
the two is processed.

However, would this mean that one of the two tasks never transitions
from TERMINATING to TERMINATED?

Original comment by riccardo.murri@gmail.com on 15 Apr 2014 at 10:35

[GoogleCodeExporter]

Fixed in SVN r3944

Original comment by riccardo.murri@gmail.com on 19 Aug 2014 at 8:56

• Changed state: Fixed