object spawner provides SAS Enterprise Guide with a TCP connection to the workspace server session.
SAS Enterprise Guide communicates directly with the workspace server.
Now, the user submits requests with SAS Enterprise Guide for processing. Results are returned to SAS Enterprise Guide. Easy as that: Code submitted, results returned
My Bratwurst example sounded simpler.
There are great troubleshooting tips available for SAS servers. Because I am afraid to add yet another note apologizing to the hardcopy readers for my long web addresses, I am going to spoof this link situation up a notch and simply say: Google for “SAS 9.4 Troubleshooting the SAS Server Tier” and you will find helpful troubleshooting tips for SAS servers.
In case you run into any problems/errors/warnings with the SAS object spawner, here are the log locations:
SAS Object Spawner log file locations:
SAS object spawner log files are located here:
Windows:
configuration-directory\ObjectSpawner\logs
UNIX:
configuration-directory/ObjectSpawner/logs
And on to the next tier ...
Middle Tier
The middle tier, or web tier, enables access with a web browser using web clients. It is pretty straight forward. Examples for web clients are SAS Studio or SAS Environment Manager.
| Tip: If you don’t know the links to access these clients, you can look at the instructions.html file, which is located per default in your configuration directory: \config_dir\Lev1\Documents |
The middle tier includes the following components:
SAS Web Application Server and SAS Web Server (http server)
Cache Locator
JMS Broker
SAS Environment Manager
SAS Web Application Server and SAS Web Server (http server)
SAS 9.4 has its own web server and web application server. This is good news because it doesn’t require the installation of any third-party web app products, such as IBM WebSphere or JBoss Application Server. During the SAS install, the middle tier is installed and configured for you.
The SAS Web Application Server is based on a commercially available third-party software product. The SAS Web Server, an HTTP server, is based on a Pivotal Web Server.
If you look at running processes, you will see Pivotal Web Server, which is the SAS Web Server, and SpringSource tc Run time, which is the SAS Web Application Server.
Looking at the configuration directory of the SAS Web Application Servers, you will notice folder names such as SASServer1_1, SASServer2_1, and so forth. The names SASServern are assigned to certain products in your SAS environment. The configuration directory is: \sas_config_dir\Lev1\Web\WebAppServer
Figure 2.6 shows the server assignments. Depending on the products you have licensed, you won’t have all the servers and with that, probably no sequential numbering.
Figure 2.6: Server Assignments
For details, see SAS Web Application Server Assignments at: https://go.documentation.sas.com/?docsetId=biwaag&docsetTarget=n1fojaysjal45on1wio1kpd3u8as.htm&docsetVersion=9.4&locale=en
Cache Locator
The SAS Web Application Server uses the cache locator to locate SAS applications that use a data cache for sharing data.
JMS Broker
The JMS Broker is used to send messages between web clients.
SAS Environment Manager
New in SAS 9.4, SAS Environment is a web client that is based on VMware Hyperic, that can be used to monitor and report on your environment. We will talk about this in more detail in Chapter 3.
Java Runtime Environment
There is no need for a JRE in SAS 9.4 as the Java environment is now part of SAS 9.4, compared to prior SAS 9 versions.
A quick note about the Java Runtime Environment, as customers ask about it once in a while. In SAS 9.4, there is no need for a JRE because the Java environment is now part of SAS 9.4, compared to prior SAS 9 versions.
Other web services that you might notice are presented in Table 2.2:
Table 2.2: SAS Web Services
| SAS Server Name | VMware Hyperic Service |
| SAS Environment Manager | Apache Tomcat |
| SAS Environment Manager Agent | HQ Agent |
| SAS Web Server | Pivotal Web Server |
| SAS Web Application Server | SpringSource tc Run time |
| SAS Web Infrastructure Platform Data Server | PostgreSQL |
Knowing the services names helps when it comes to monitoring your environment, so you can recognize what process is actually running.
Wait for it – a link reference ... There is a great article called “SAS 9.4 middle tier architecture: need a map?“ which I would like to recommend. https://blogs.sas.com/content/sgf/2013/09/19/sas-9-4-middle-tier-architecture-need-a-map/
SAS Client Tier
There is not much to say about this tier: it is where your SAS desktop clients run and where your users access SAS web clients via browser.
Data Tier
The data tier “holds” all your data sources. This can be SAS data sets, DBMS tables, multi-dimensional data etc. – simply everything data. SAS offers many options for connecting and accessing data sources, some of which we will cover in Chapter 5, Metadata Library Administration.
Summary
We covered a lot of ground in this chapter. The idea is to provide you with basics, to help you understand the SAS architecture. If you know how it works, and what it includes, SAS administration will be much easier. Here are some good resources for general SAS architecture:
Concluding this chapter, I would like to point out one last find, called ”Grand Designs: Why It Pays to Think About Technical Architecture Design Before You Act”: http://support.sas.com/resources/papers/proceedings13/475-2013.pdf
When it comes to architecting SAS, or, adding or modifying an already existing SAS environment, be considered and think it through carefully, make sure you have a good plan in place.
Chapter 3: Administration
