CernLbdGateway

This is the LHCb CERN LBD group page describing the local gateway machines



Local, batch, grid

What is it?

A gateway machine is a computer which is logged onto remotely, shared by multiple (limited) users.

What is it for?

The gateway machines are provided so that you can:

  • Maintain a session indefinately
  • Have a single machine name to remember
  • Run low-CPU consuming applications
  • Run mid-CPU consuming applications heavily 'niced'

Notably it is not for:

  • Do not run high-CPU consuming tasks, use the batch system or lhcbt3 for that.
  • Try not to rely on the temp directory, use your own personal scratch space or the group afs space for that, see CernLbdDiskSpace.

Examples:

  • Submitting, monitoring and retrieving ganga jobs
  • Running small jobs against the nightlies
  • Compiling your code
  • Opening root files for viewing
  • running quick root macros

To Windows, from any platform:

Use the CERN Terminal Services

Your cernts session will stay open for a very long time.

To check the service status and disconnect remotely see here

If you have a windows desktop, you can double-hop your remote desktop session, from cernts to your desktop machine.

To SLC5 from any platform:

The LBD group with the fantastic help of the online team has provided a local SLC5 gateway machine, lbcsvr01 running a NX server. It is on the CERN network, afs-connected, and you will be able to keep a session open indefinitely.

Specs for lbcsvr01:

  • 12-core,
  • 24-GB-ram
  • 10GB network link,
  • stored in building 157
  • administrated with help from the online team, LoicBrarda and NikoNeufeld.

- Access:

  • If you are a member of LBD you are entitled to access the server
  • To gain access to the LBD server, contact RobLambert or NikoNeufeld, because your account needs to be added manually
  • You will be added to the lbcsrv-users e-group, and added individually to the machine
  • by requesting to join the lbcsrv-users e-group, Rob/Niko know you'd like to be added to the machine
  • Once you leave LBD, you will need to be removed from the list, and from the machine, but this will be done fairly, so don't panic... best to remember that it will happen, though

- Connecting through NX

We are now using the X2Go implementation (still using the NX libs)

X2GO is a remote-desktop equivalent for linux and other operating systems.

NX will let you connect to the same desktop from multiple locations, and maintain that entire desktop as long as you wish.

X2GO is an improvement over VNC thanks to the simpler configuration, connection, and cut-pasting which was never 100% supported in VNC.

Over the CERN network:

  • Install the X2GO client on your machine from the website X2GO
  • clients can be Mac, Windows or Linux each of various flavours
  • Configure as you like, and run
  • choose the server lbcsrv01.cern.ch, default port
  • Authenticate with your CERN username/password

From outside CERN.

- Management

The administration of CERN lbd servers will be done on a fair-usage policy, if you are interfering with someone else, you will be asked to stop.

For management instructions see LBDGatewayManagement

- Known problems:

  1. afs freezing: probably needs update of open afs client as was done on lxplus

- FAQ

Emacs can't find fonts

  • emacs cannot find fonts
    ~ >emacs &
    >  Warning: Cannot convert string "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-*" to type FontStruct
  • If you're on a windows machine you also need to install all the client font packs from the NX website.
  • (it's on the same page where you download the windows client)

Only the number pad works!

  • You can't seem to type anything, check the num pad, and it works
  • the keyboard mapping is wrong, probably
  • check what's in the server $HOME/.nx/C-<last-session>/options, if it says simply keyboard=pc105/en_US AND your local computer is not en_US then the local strings in your client are not set correctly.
  • follow the instructions here to fix it... but you'll need the client installed somewhere you have write permission!

Alternatives:

See CernLbdPlatform.

-- RobLambert - 15-Nov-2010

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