Using the lsst-dev Server¶

Overview of Cluster Resources¶

• List of available development servers and their intended use.
• System announcements of the status and planned down-time.
• Real-time system status (requires login).
• Reference/test data from SDSS DR7 for Stripe82 is located at: /lsst7/stripe82/dr7/runs.
• Report system issues to lsst-sysadm _at_ ncsa.illinois.edu

Set up SSH Keys¶

You will need to establish public/private keys to access NCSA development machines via SSH. Here’s how to set up your SSH client to use keys:

mkdir ~/.ssh
chmod 700 ~/.ssh
ssh-keygen -t rsa

Generating public/private rsa key pair.
Enter file in which to save the key (/home/username/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/username/.ssh/id_rsa.
Your public key has been saved in /home/username/.ssh/id_rsa.pub.
The key fingerprint is:
a1:b2:c3:45:67:89:d1:e2:f3:54:76:98:00:aa:bb:01 username@hostname.lsstcorp.org

scp .ssh/id_rsa.pub lsst-dev.ncsa.illinois.edu:mymachine_rsa.pub
ssh lsst-dev.ncsa.illinois.edu

touch ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys
cat mydevmachine_rsa.pub >> ~/.ssh/authorized_keys
exit

ssh lsst-dev.ncsa.illinois.edu
Enter passphrase for key '/home/username/.ssh/id_rsa': # type your key passphrase

Select Appropriate Developer Tools¶

The lsst-dev system is configured with the CentOS 6.7 as its operating system. This release of CentOS provides an old set of development tools, centred around version 4.4.7 of the GNU Compiler Collection (GCC). This version of GCC does not satisfy the prerequisites for building the LSST stack. Before proceeding, therefore, you should enable the Red Hat Developer Toolset version 3 (devtoolset-3) which has been pre-installed. This provides an updated toolchain, including GCC 4.9.2.

Enable and test devtoolset-3 using the scl command as follows (replacing bash with your shell of choice if necessary):

scl enable devtoolset-3 bash
gcc --version
gcc (GCC) 4.9.2 20150212 (Red Hat 4.9.2-6)
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

The Developer Toolset includes version 1.9.3 of the Git version control system. If you prefer the (slightly) more recent version 1.9.4, you may also wish to enable the git19 package. This may be done at the same time as enabling devtoolset-3.

scl enable devtoolset-3 git19 bash

You may wish to automatically enable devtoolset-3 every time you log in to lsst-dev by adding it to your shell initialization files. For example, try adding the following to ~/.profile:

exec scl enable devtoolset-3 bash

Load the LSST Environment¶

Two ‘shared’ installations of the LSST software stack are available on lsst-dev:

/ssd/lsstsw/stack/

This is installed on local (SSD) storage. It provides for maximum performance when executing jobs on lsst-dev directly.

/nfs/lsst4/lsstsw/stack/

This is installed on networked storage (NFS). As such, it is likely to be slower than local storage when running on lsst-dev. However, the NFS disk is cross-mounted to other development servers at NCSA, including those configured as part of the HTCondor pool. This stack can therefore be relied upon to be consistent when launching jobs across the cluster.

This installation is regularly updated to recent releases and weekly builds of the lsst_distrib top-level package; the most recent build is tagged as current. Add this shared stack to your environment and set up the latest build of the LSST applications by running:

source /ssd/lsstsw/stack/loadLSST.bash
setup lsst_apps

(substitute loadLSST.csh, loadLSST.ksh or loadLSST.zsh, depending on your preferred shell, and use /nfs/lsst4/lsstsw/stack/loadLSST.bash to access the NFS-backed stack).

Since this stack is shared, all members of the lsst group have permission to declare products within it, thereby making new products and versions available for other users. For example, to share myVersion of myProduct, which you have built and installed in directory productDir, run:

eups declare myProduct myVersion -r productDir

To declare a product for your own use without making it available for others to setup, tag it with your username:

eups declare myProduct myVersion -t $(whoami) -r productDir

Please make use of this capability responsibly: make public declarations only of those products which are of general use, and remove them when they become obsolete:

eups undeclare myProduct myVersion

Refer to the EUPS Tutorial for more information on working with EUPS product stacks.

Note that the SSD and NFS-backed stacks are independent: while both will automatically contain the latest LSST software releases, other products declared in a given stack will not automatically become available in the other.

Administators may wish to note that the shared stack is automatically updated using the script ~lsstsw/shared-stack/shared_stack.py, which is executed nightly by Cron.

Configure Remote Display with xpra¶

xpra can be thought of as “screen for X” and offers advantages over VNC. It can be very handy and efficient for remote display to your machine from the LSST cluster (e.g., debugging with ds9) because it is much faster than a regular X connection when you don’t have a lot of bandwidth (e.g., working remotely), and it saves state between connections. Here’s how to use it:

On lsst-dev:

xpra start :10
export DISPLAY=:10

You may have to choose a different display number (>10) if :10 is already in use.

On your local machine, do:

xpra attach ssh:lsst-dev:10

You may leave that running, or put it in the background and later use:

xpra detach

Then you can open windows on lsst-dev (with DISPLAY=:10) and they will appear on your machine. If you now kill the xpra attach on your machine, you’ll lose those windows. When you reattach, they’ll reappear.