Components of the SAS LASR Analytic Server

The following sections identify some software components and interactions for SAS LASR Analytic Server.

When the SAS client initiates contact with the grid host to start a SAS LASR Analytic Server instance, the SAS software on that machine takes on the role of distributing and coordinating the workload. This role is in contrast to a worker node. This term applies to a distributed SAS LASR Analytic Server only.

This is the role of the software that receives the workload from the root node. When a table is loaded into memory, the root node distributes the data to the worker nodes and they load the data into memory. If you are using a co-located data provider, each worker node reads the portion of the data that is local to the machine. The data is loaded into memory and requests that are sent to root node are distributed to the worker nodes. The worker nodes perform the analytic tasks on the data that is loaded in memory on the machine and then return the results to the root node. This term applies to a distributed SAS LASR Analytic Server only.

SAS LASR Analytic Server performs analytics on tables that are in-memory only. Typically, large tables are read from a co-located data provider by worker nodes. The tables are loaded quickly because each worker node is able read a portion of the data from local storage. Once the portion of the table is in memory on each worker node, the server instance is able to perform the analytic operations that are requested by the client. The analytic tasks that are performed by the worker nodes are done on the in-memory data only.

SAS LASR Analytic Server uses two types of signature files, server signature files and table signature files. These files are used as a security mechanism for server management and for access to data in a server. When a server instance is started, a directory is specified on the PATH= option to the LASR procedure. The specified directory must exist on the machine that is specified as GRIDHOST= environment variable.

In order to start a server, the user must have Write access to the directory in order to be able to create the server signature file. In order stop a server, the user must have Read access to the server signature file so that it can be removed from the directory.

In order to load and unload tables on a server, the user must have Read access to the server signature file in order to interact with the server. Write permission to the directory is needed to create the table signature file when loading a table and to delete the table signature file when unloading the table.

If you specify a filename in the CREATE= option in the LASR procedure, then you start a SAS LASR Analytic Server instance, the LASR procedure creates two files:

The server description file contains information such as the host names of the machines that are used by the server instance and signature file information.

In the LASR procedure, the server description file is specified with the CREATE= option. The server description file is created on the SAS client machine that invoked PROC LASR.