[Pvfs2-developers] Distribution by hostname

[Bradley W Settlemyer]

Julian Martin Kunkel wrote:
> Hi,
>> So I think we're mostly trying to work out what our API should really 
>> be, whether we should extend the distro functionality vs. going totally 
>> to hints, and if we go to hints what that API should look like, right?
> probably the distribution needs a function which initializes/sets the internal 
> parameter depending on the string. Maybe another one which fancy writes the 
> parameters to a char buffer.
> 
>> I'm down with that.  For the record, my concern over strings isn't in
>> our processing them - its the users having to muck with them -
>> especially when passing numeric data.  I just worry about lots of
>> mallocing/string copying blech when all you really want to do is set the
>> stripe size to the variable x.
> I think extra mallocing is not really necessary only once to generate the 
> string which can be generated with snprintf  the string could look 
> like "ioservercount=2;ioservers=node1,node4;dist=simplestripe;dist_stripesize=65536"
> whereas options without the prefix "dist_" may be processed by code common to 
> all distributions. 
> 

Doesn't this just bring all the age old problems with  text processing: 
  escape characters (typically backslashes), inextensible formats, etc. 
  I'm not opposed to it, but I can't stand custom formats.  You're gonna 
want some way of differentiating floats, ints, strings and vectors I 
suspect.

I would say either use the same format as the server config file, or 
embed an XML parser in the thing and be done with it.

For parsing my additional mpi-io hints I was able to get away with a 3 
lines of regexp code.  That won't be possible in more general cases I 
don't think.

Cheers,
Brad