[seek-dev] get operation in ecogrid query
bzhu at sdsc.edu
Tue Dec 2 16:28:06 PST 2003
I have some comments here.
1. In SRB, the identifier will be the SRB ID.
In the get operation for SRB, this SRB ID is translated into following:
host name (e.g. multivac.sdsc.edu)
Physical file name with path in that machine.
In this case, the source will be either NULL or a port number in getting
a SRB file.
2. It is better for the return value from 'get' operation to:
0 --> succeeded.
a negative number -> failed. The number is the error code
corresponding to an error.
In SRB, failure to retrieve a file
has many causes. 0 and 1 is not
not sufficient to handle error code
3. We need to have a way to let system admin to turn on or off the Debug
by modifying some configuration file(s) such as server-config.wsdd
before starting SEEK Ecogrid
factory services. I wonder how Tomcat is handling this. If they already
have a build-in function to
check if Debug is on or off, we need to put such function call for each
From: seek-dev-admin at ecoinformatics.org
[mailto:seek-dev-admin at ecoinformatics.org]On Behalf Of Jing Tao
Sent: Tuesday, December 02, 2003 2:59 PM
To: seek-dev at ecoinformatics.org
Subject: [seek-dev] get operation in ecogrid query
After struggling with some issues, the framework of get operation in
ecogrid query interface is almost done(I have not implmented read document
from metacat part, but that is not hard). Before I do that, I would
like to get some response.
The get method looks like:
int get(URI source, URI destination, String identifier).
This method is base on gsiftp and will return 1 if transfer successfully,
otherwise return 0. Besides server to client transfer, this method also
support third party transfer (ftp sever to another ftp server) too.
Now the query porttype is secured because running gsiftp need the user's
credential. So user should have a certification if he need to run the
The tansfer is base on file system. For example, you call the method like
URI source = new URI("gsiftp://pine.nceas.ucsb.edu:5678");
URI dest = new URI("file:///tmp/file1");
get(source, dest, "tao.11.1");
Metacat would like read tao.11.1 from database and write it to a file.
Then gsiftp server will transfer this file to local file /tmp/file1. It has
lot of I/Os. Maybe this way is good for srb (they store data as file).
In the code, System.out.println is used for debug info. I am think if we
need a debug class for whole seek java code or for ecogrid java code?
Any comments and suggestion are appreciated!
National Center for Ecological
Analysis and Synthesis (NCEAS)
735 State St. Suite 204
Santa Barbara, CA 93101
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