SRB workshop

Demonstration 1: SRB client tools

1. Introduction

The objective of this demonstration is to explore the three SRB client tools shown in the lectures:

The plan is to give you the scope to explore in whatever way you like, rather than guide you through a set of pre-determined steps.

You will need some data to work with. If you want to work with some data of your own, you should transfer the data to your PC from your home computers. Alternatively, you can download the following files from the NIEeS web site:

You may want to rename files frequently to avoid confusion when you transfer between your computer and the SRB.

You will be provided with username/password combinations for the SRB and for the unix machines you will be using for part of thr demonstration.

You will also be asked for the following information in the various tools:

Information about the SRB can be obtained from

http://www.sdsc.edu/srb/

We will be using version 3.3.1 of the SRB (but note that the current release version is v3.4; we are using a slighly older version to ensure stability in the demonstration).

2. InQ windows interface

Information about InQ can be obtained from

http://www.sdsc.edu/srb/inQ/inQ.html

InQ should be pre-installed on the desktop of your PC, but if not, you can download it from the above site. It simply produces a single executable file. Note that you must download version 3.3.1 (if you download other versions they will not work in this demonstration; this version does actually work with v3.4 of the SRB).

Every user has a home directory, which you will go to immediately. You should try the following (in whatever order you like)

  1. Ingest a file into the SRB – merely a flashy name for putting a file into the SRB (but note that it does more than a file transfer – there is also a transfer of information to the metadata catalogue, which will be updated as you manipulate the files). With InQ you can simply transfer files by dragging files from the PC desktop into the InQ window. Note that you need to select the physical data location (data vault) from a menu list (there are two vaults in Cambridge).
  2. Change the file view in InQ to show the information listing. Note that you have information such as version number, physical location, date, size etc.
  3. Create folders/collections and put your files into a collection. You will need to do this to transfer files to the dataportal.
  4. Try using some standard manipulations such as dowloading and deleting files.
  5. Try changing permissions on files.
  6. Move files between vaults.
  7. Create replicas of the data, placing the new replica in a different vault.

3. MySRB web interface

You can acces the MySRB web interface to the SRB from the following web link:

http://holbein.escience.cam.ac.uk/mysrb.html

You will find the following login window ...

Once you have completed the login information and pressed the Login button, you will have a new window ...

Press the "Take Me to My Collection" button, and you will get a view of your SRB data collection ...

Hopefully you will have more files than in this example!

You should repeat the tasks carried out under part 2. The SRB has some irritating quirks, such as not updating the page when you would like it to, and asking for information you would normally hope would be chosen by default (e.g. the name of the file when ingesting a file). But otherwise, the MySRB interface performs the same basic functions as the InQ client tool.

4. Scommands: unix command-line interface

Use the Putty ssh client tool (instructions here) to log in to one of the NIEeS linux machines. Details of the IP address and username/password you should use are provided.

First, take a look at the files contained in the .srb folder using the command combination:

cd .srb
ls -a
cat .MdasENV
cat .MdasAUTH

Please ask if you are not familiar with the commands cd, ls and cat, or look at these web links for information on cd, ls and cat respectively. These files contain some basic settings for your use of the SRB, mirroring the information you would have given InQ and MySRB.

To get going, type the command Sinit to begin your SRB session.

The full list of commands and information on their use is available from the Sman pages:

http://www.npaci.edu/DICE/SRB/srbcommands.html

You should keep this web page open for information on each tool.

To start, if you have already carried out the earlier parts of this demonstration, the command Sls will provide a listing of the files you have previously stored on the SRB.

You can now try the following, and use InQ or MySRB simultaneously to observe changes:

  1. Use the Sget command to download files from the SRB to your current directory.
  2. Rename files and use the Sput command to upload files. Try using some of the different options as described in the Sman pages.
  3. Try changing permissions of files on the SRB using the Schmod command.
  4. Try some of the other Scommands, such as Srm to delete a file on the SRB, and Sreplicate to create data replicas.

At the end, type Sexit to close your session. This has the effect of tidying up various files; the only effect of ignoring the use of this command is that you will be left with some files that would otherwise have been deleted.

5. Summary

From this demonstration, you should

  1. Have experience of the three client tools for the SRB.
  2. Obtained some experience of how the SRB handles data (e.g. data replicas, use of SRB vaults)

In tomorrow's demonstration, the SRB will be used in conjunction with work being carried out at CCLRC on the use of metadata, and you will need to use some of the tools you have been looking at today.

Last update: Tue, Jan 10, 2006