[seek-dev] RE: OGSA version grid-ftp

Bertram Ludaescher ludaesch at sdsc.edu
Thu Nov 6 22:05:21 PST 2003

Jing, Bing and others (esp. Matt):

Can you have a look at

This is a slide I recently used to illustrate how the Grid-enabled
data transfer could be possibly accomplished in a transparent manner
in Ptolemy-II. 

In the figure, A and B are two actors running in PTII as independent
Java threads. Logically, A sends B a data token X. As it turns out A
is really a PTII proxy for some remote grid service GA. Similarly for
B and GB. So when A sends X to B (logically), what really happens is
all that other stuff that you see (handles being passed back and
forth, so that eventually GB requests a direct data transfer from GA.

When the actor B receives message #3, it does NOT indicate completion
of data transfer (or in PTII lingo: the token X from A did NOT arrive
yet at B). This happens only when #7 comes in, at which point B
logically/virtually has received X.

Is this how this is supposed to work? 
If not, how then?



>>>>> "JT" == Jing Tao <tao at nceas.ucsb.edu> writes:
JT> Hi, Bing:
JT> Thanks for the suggestion and info. I am looking at RFT and it is an 
JT> OGSA based service that provides interfaces for controlling and monitoring 
JT> 3rd party file transfers using GridFTP server. Basically, client pass a 
JT> src and des gridftp url, then the grid service will control the file 
JT> transfer.
JT> I already install the grid service (RFT) in my local machine and 
JT> successfully transfer file from my local gridftp server  to my local 
JT> gridftp sever :). I tried to transfer form my local machine to dev and got some 
JT> errors.
JT> I am thinking we can modified the RFT code to achieve our GET method(I 
JT> already foud source code). I think there are two parameters will be pass 
JT> to GET, one is the document identifier and the other is destination url 
JT> (either a gridftp url or file url). Then GET method will do the two steps as you 
JT> described(first get the source for Metacat or SRB, then call gridftp JAVA 
JT> API to send it). A integer will be returned from GET indicates if the ftp transfer
JT> successes or fails.
JT> The issue I am think is about certicification. Probably it will take some 
JT> time to figure out.
JT> Thanks.
JT> Jing
JT> On Wed, 5 Nov 2003, Bing Zhu wrote:
>> Matt and Jing,
>> Currently the OGSA version of grid-ftp is not available according to
>> William(Bill) Allcock's
>> mail below.
>> Here is what I suggest for our GET.
>> If the Java package for grid-ftp as you pointed in the web page
>> http://www-unix.globus.org/cog/jftp/guide.html
>> work, we can implement our GET file JAVA client with following steps.
>> 1. GET contacts our Ecogrid system with a Ecogrid object ID and the grid
>> service
>> returns actual host name along with physical path. (This is a OGSA
>> service call.)
>> 2. GET then call Java grid-ftp APIs to contact the grid-ftp server in that
>> host to get
>> the file transferred.
>> Since Metacat store files as links, this approach should work well with
>> Metacat.
>> For the SRB system, if files are actually stored inside SRB, streaming data
>> of files into grid-ftp server can be a pain.
>> The grid-ftp driver I developed is another way around, i.e. SRB is on top of
>> grid-ftp. But I don't worry about this.
>> SRB has other data model of using file registration in which files resides
>> in their own place(s) and SRB just have links
>> pointing to them. This is exactly the same as the implementation in Metacat.
>> So I didn't see any problem here.
>> Bing
>> -----Original Message-----
>> From: William E. Allcock [mailto:allcock at mcs.anl.gov]
>> Sent: Wednesday, November 05, 2003 6:11 PM
>> To: bzhu at sdsc.edu
>> Subject: RE: OGSA version grid-ftp
>> The only thing we have right now, is the Reliable File Transfer Service
>> (RFT)
>> http://www-unix.globus.org/toolkit/reliable_transfer.html
>> The rest of the OGSI-ification of GridFTP is VERY up in the air right now.
>> The ideas around this work are mostly being discussed in the GGF Data Access
>> and Integration WG.  This will be a major thrust for next year, but right
>> now
>> I can't really tell you what it will look like, or when we will deliver it.
>> Bill
>> >-----Original Message-----
>> >From: Bing Zhu [mailto:bzhu at sdsc.edu]
>> >Sent: Tuesday, November 04, 2003 17:20
>> >To: William E. Allcock
>> >Subject: OGSA version grid-ftp
>> >
>> >
>> >Bill,
>> >
>> >This is Bing again. This time I am sending the mail as a developer from the
>> >the Science Environment for Ecological Knowledge (SEEK) project.
>> >
>> >We are interested in an OGSA version (or wrappers) grid-ftp. I heard in
>> >GlobusWorld 2003
>> >in San Diego that your team had been working on this. Would you provide me
>> >some updates
>> >or some web links so that I can do an evaluation for the SEEK project? We
>> >are also interested
>> >OGSA-version grid-ftp APIs. Thanks.
>> >
>> >Sincerely,
>> >Bing
>> >===============================================================
>> >Bing Zhu
>> >Programmer/Analyst III
>> >Data and Knowledge Systems
>> >San Diego Supercomputer Center
>> >(858)534-8373
>> >bzhu at sdsc.edu
>> >===============================================================
>> >
JT> -- 
JT> Jing Tao
JT> National Center for Ecological
JT> Analysis and Synthesis (NCEAS)
JT> 735 State St. Suite 204
JT> Santa Barbara, CA 93101
JT> _______________________________________________
JT> seek-dev mailing list
JT> seek-dev at ecoinformatics.org
JT> http://www.ecoinformatics.org/mailman/listinfo/seek-dev

More information about the Seek-dev mailing list