Information for Visiting Astronomers
Date: 22-11-09
Downloading your Observations to your Laptop by using the DfsExport Tool software
Setup for a New Visitor
On the visitor laptop (download to a single laptop only, per UT is permitted):- The vistor laptop must have java 1.4 (run java -version and verify)
- The visitor laptop must be connected to the blue cable (not the wireless LAN).
- You must know the IP of the visitor laptop - (it changes) - for linux run "ifconfig" on the laptop to find the assigned IP (or "/sbin /ifconfig" when not in path)
- Create a local directory for the software (for example):
> mkdir ~/dfs
> cd ~/dfs - Download the dfsexport software to the laptop and save it in the
software directory (e.g. ~/dfs):
You can download it here (it is in the format of .jar) - Create a directory for saving dowloaded data:
> mkdir ~/mydata - Start the download tool on the laptop AND leave it running:
> java -jar ~/dfs/dfsexport.jar ~/mydata <IP of offline WS> 6666
The IP numbers of offline WSs are as follows:
wgsoff1 134.171.224.3 wgsoff2 134.171.224.4 wgsoff3 134.171.224.6 wgsoff4 134.171.224.13 wvgsoff 134.171.249.9
On offline-WS as astro<x>:
- Edit ~/.dfsexport.rc
set RECEIVER.IP keyword to IP address of the laptop
set KEYWORD.OBS.PROG.ID keyword to the full observing run of the visitor e.g. "'075.C-0381(B)'"
- Test the connection to the laptop:
> dfscp -testconnection
If the test connection message is not displayed on the laptop, one of the following is likely the cause:- the dfsexport tool was configured with the wrong IP address
- the laptop is running a firewall (in which case it should either be disabled or port 6666 should be opened)
- When ever required/desired data may be copied to the laptop using
dfscp, e.g.
> dfscp /data-ut1/raw/2005-06-05/*.fits
If the process on the laptop is stopped transfers will stop.
General Information
The DfsExport tool is a simple means to export data from the offline workstation to the visitor laptop.
The intention is to provide an easy means of getting data to the visitor to enabling them to start work on the science data using their own tools while at the telescope.
The tool comprises of two applications:- DfsExport command-line tool run on the offline workstation for
sending a file to a configured visitor laptop. The DfsExport command is
wrapped in the dfscp script, which permits sending multiple files.
- DfsImport process which runs on the visitor laptop. The process is started and left running for the duration of the download (or all night).
The key aspects of the software for exporting data to visitor laptops are:
- cross-platform to accommodate the range of laptops visitors run
- outbound connections from control LAN only (the laptop has no access
to the control)
- small download and configuration time to run client (DfsImport) on
visitor laptop
- easy integration of DfsExport software into offline WS software:
scripts, Gasgano and dataSubscriber.
- communications error handling and guaranteed data delivery are not important - if a file fails to send or is truncated, it is enough that it is resent by hand.
DfsExport/dfscp (software on offline WS)
The sending of files to the visitor laptop requires the following information to DfsExport:
- the path of files to send, which is supplied on the command line
- the host IP and port running DfsImport, which is given in the configuration file.
DfsExport reads a PAF (Param) format configuration file $HOME/.dfsexport.rc which contains the IP and port of the DfsImport process, as well permits configuring the program id of the visitor. This keyword will restrict sending of FITS and TFITS files to those with the OBS.PROG.ID value given in the configuration file, or calibration data (defined as TFITS and FITS data containing no OBS.PROG.ID keyword, or where OBS.PROG.ID is for a period <= 60). All non FITS and TFITS data may be sent without check. This is a very mild form of security to restrict the visitor from exporting the incorrect data from the offline WS.
DfsExport is a java application comprising of the following JAR libraries:
- dfsexport.jar - the library for DfsExport/DfsImport code.
- dfs.jar - stripped down jar file containing Param/Configuration reading classes from OHS code and FITS reading classes from Gasgano dfs.jar.
- gnu-regexp.jar - required for OHS code, though not used.
DfsExport is called indirectly from dfscp.
DfsImport is a java application comprising of the dfsexport.jar file.
This is the only download required to run the tool on the visitor
laptop.
The laptop must be installed with Java 1.4 runtime, which is likely if P2PP is installed.
DfsImport (software for visitor laptop)
The 6666 is a port number used by DfsImport. If for some reason there are conflicts using 6666 another may be specified, however the configuration file of DfsExport must also be updated with the alternate port number.
Once running the program will wait for connections from the specified IP number and download data as sent by DfsExport/dfscp on the offline workstation.
The output for DfsImport should resemble the following:
"Waiting for connections."
DfsImport will not overwrite an existing file and will report an error. DfsImport will receive a closed connection (and display an error) when sending a file that already exists on the laptop.