Q. How can I control the number of concurrent file transfers?

A. When HSI starts up, it obtains the maximum number of concurrent file transfers that are allowed to be active from a setting on the HSI Gateway server.  Users and site administrators can reduce, but not increase, this value.  

This is intended to provide a way to reduce the HPSS I/O load on smaller systems that may not be able to handle the same number of transfers as larger systems, or for users that are memory limited or CPU-limited to reduce their individual system resource usage.

There are two ways to do this:

1. Set  max_xfer_threads = n in the global hsirc file, or the user’s private .hsirc file.  The user’s private .hsirc setting overrides the global setting if both are specified.  For example, if the site admin has set a maximum of 25 concurrent transfers, the system admin might reduce it to, say, 15 by setting:

            max_xfer_threads = 1

in the global hsirc.  An individual user may decide to reduce it ever further by setting:

            max_xfer_threads = 5

in their private $HOME/.hsirc.

2. For a particular ‘put’, ‘get’, ‘hashcreate’ or ‘hashverify' command, use the -X n option