[seek-dev] Transfer huge data file in EcoGrid

[Jing Tao]

Hi, everyone:

It seems we haven't found a way to stream big data object from EcoGrid 
service to client machine directly.

Here is a hybrid approach which i am thinking to figure out this issue by 
use grid ftp.

Hybrid means this approach will need both client lib and web service. The 
main task will be taken in client side and web service will provide some 
info.

In client lib, we will created a method named "transfer" and it signature 
will be:

public void transfer(String host, int port, String docId, DataSink sink)

This method will initialize a GridFTPClient object(using host and port) 
and call a "extenedGet" method to get the remote file:
extendedGet(String remoteFileName, long size, DataSink sink)

In order to get remoteFileName and file size, we need two web services in 
EcoGrid:
String getFilePath(String docid)
long   getFileSize(String docid)

The above two web service method will be called in "transfer" method 
before calling "extenedGet" in order to get remoteFileName and file size.  

This approach is not a pure web service, client software(such as Kepler) 
should stick the ecogrid client lib. In ecogrid service, we also need to 
run a grid ftp server. 

Any suggestion and comment will be appreciated.

Jing


-- 
Jing Tao
National Center for Ecological
Analysis and Synthesis (NCEAS)
735 State St. Suite 204
Santa Barbara, CA 93101