Second Birthday

It’s PlatformAdmin.com’s 2nd birthday this week!

The past 2 years have gone very quickly I must say. I set out with a goal of writing a least 1 post every month. Not very ambitious I know, but realistic for me nonetheless! I’ve never been much of a writer. I’ve always been impressed by people who appear to write so well, and even more so by those that have the stamina and skill to author and publish a book. Maths, Science & Computers have always been my thing ever since way back in school and I have generally avoided writing unless I had to. I do remember reading a blog post by Joel Spolsky a while back where he said that “Writing is a muscle. The more you write, the more you’ll be able to write.” It sounded pretty reasonable to me. As a training course instructor I’ve always found that one of the great benefits of teaching was that I necessarily had to learn much more of the details for whatever I was teaching. I’ve found that the same appears to be true about writing publicly accessible blog posts. The fear of being asked tough questions or being challenged on topics turns into the pleasure of learning more!

Well, I’m pleased to say that Continue reading “Second Birthday”

SAS & IWA: Reviewing SPNs

My last post was about configuring additional Service Principal Names (SPNs) in Active Directory to support the use of Integrated Windows Authentication (IWA) in a SAS® platform installation that uses host name aliases in preference to physical host names.

When working on a SAS & IWA setup like this, I’d start by reviewing the currently registered SPNs for all of the SAS servers involved (as well as any other servers that might be accessed from a SAS server using IWA). This gives an idea of what SPNs might have already been added, which ones still need to be added, and potentially which ones might need to be removed.

This is the command I use Continue reading “SAS & IWA: Reviewing SPNs”

SAS & IWA: Host Name Aliases and SPNs

I’m quite keen on using host name aliases, rather than their physical host names, when referring to machines in SAS® platform installations. It does however mean a little extra configuration is required when using Integrated Windows Authentication. That is what this post is about: configuring Active Directory with additional Service Principal Names (SPNs) based on the aliases.

Host name aliases have several benefits over using physical host names. They can be easier to remember (e.g. sasmeta v.s. p106547). They can be easily redirected from primary environments to disaster recovery environments (e.g. sasmeta from p106547 to d106547) with no client reconfiguration requirements. They also allow host machines to be readily renamed if/when required with little or no changes to SAS configuration files, programs and/or metadata.

Whilst they have obvious benefits, Continue reading “SAS & IWA: Host Name Aliases and SPNs”

SAS Management Console over SSH

I was asked recently how to get SAS® Management Console to remotely access a SAS metadata server using SSH tunnels. In the absence of a VPN connection to your network, SSH can be an alternative for SAS Management Console access to a remote SAS metadata server.

I am a huge fan of SSH (Secure Shell). I have been using it several times a day for many years now. It’s great. If you haven’t heard of SSH before, take a look at the Wikipedia page for Secure Shell. Here’s a quote from the page that provides a nice intro/summary:

Secure Shell (SSH) is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network.

Here are a couple of methods for using SAS Management Console over SSH:

1. Remote execution of SAS Management Console with X11 forwarding to the client

This method can be used when you are accessing a SAS platform installation on Linux or UNIX and have SSH client software and X server software on your remote workstation. Mac or Linux workstations are great for this since they usually have all the required software pre-installed. Windows can also be used if you obtain SSH client and X server software. I personally use Putty as an SSH client when I am working on Windows and would defintely recommend it. I have no specific recommendations for an X server on Windows since it’s been a long time since I’ve done X on Windows.

Assuming, as a SAS platform administrator, you have remote SSH access to the SAS metadata server machine then you can use SSH from your workstation to execute the SAS Management Console remotely and forward the X display to your client workstation.

Here’s an example command to do this:

ssh -X sasmeta.example.com /opt/sas93/SASManagementConsole/9.3/sasmc

Which means SSH connect, with X11 forwarding, to the machine sasmeta.example.com and then execute the SAS Management Console (/opt/sas93/SASManagementConsole/9.3/sasmc) on that remote machine sending the X windows back to the client workstation.

2. Local execution of SAS Management Console with SSH tunneling

SSH also allows you to configure a tunnel – a local port on your workstation that that forwards traffic to a designated server and port in the remote network. This tunnel can be used to make a remote service appear to be a local service. We can use it to make a remote SAS metadata server port appear to be on the local workstation so that a local installation of the SAS Management Console can connect to it as if it had a local metadata server.

Here’s an example command to do this:

ssh -L 8561:sasmeta.example.com:8561 sasmid.example.com

Which means SSH connect to the machine sasmid.example.com and establish a local machine port (8561) that forwards traffic to the remote host/port sasmeta.example.com:8561 accessible via sasmid.example.com. If you are not using public key authentication (recommended) then you will be prompted for a user id and password for the server. Once the connection is active, a local SAS Management Console can be started and will be able to access the remote SAS metadata server using a connection profile that connects to a metadata server on host/port localhost:8561. All traffic to this local port will be sent to the remote metadata server over the SSH tunnel.

Bear in mind that this only makes the metadata server port available on the local machine. So the local SAS Management Console instance can only access the metadata server. It doesn’t necessarily make the client fully functional as it may require additional connections to additional servers e.g. access to a SAS Object Spawner for a SAS Workspace Server session or a connection to the SAS Content Server. You could look into forwarding other ports and will also need to modify your local hosts file to redirect the remote host names found in metadata to the localhost interface. For anything more complex than pure metadata server access it would probably be easier and more robust to use a VPN connection (or remote access via something like X or RDP to remote network client workstations).