SAS 9.1.3 Integration Technologies » Server Administrator's Guide

Pooling and Load Balancing
Pooling
Planning and Configuring Pooling
Load Balancing
Planning and Configuring a Load-Balancing Cluster
Planning the Load-Balancing Algorithm
Reference Materials
Fields for the Server Definition
Fields for the Pooling Logical Server Definition
Fields for the Load-Balancing Logical Server Definition
Pooling and Load Balancing

Pooling and Load Balancing

Overview of Pooling and Load Balancing

Pooling and load balancing are features that improve performance for SAS Workspace Servers and SAS Stored Process Servers.

Pooling and load balancing improve performance in different ways:

Pooling
creates a set of workspace server connections that are reused. This avoids the processing that is associated with creating a new server connection for each user. You can also use pooling to distribute server connections across machines.

Load balancing
distributes the server load across server machines. For stored process servers, the server load is also distributed across server processes. Load balancing is not useful for workspace servers if you only have one server machine.

The following table shows the pooling and load-balancing configurations that are supported for each type of IOM server:

Supported Pooling/Load Balancing Configurations
IOM Server Type Pooling Load Balancing
SAS Workspace Server with COM connection yes no
SAS Workspace Server with IOM Bridge connection yes yes, by balancing across server machines
SAS Stored Process Server with IOM Bridge Connection no yes (required), by balancing between multiple server processes. The server processes can be on a single server machine, or on multiple server machines.
SAS OLAP Server no no
SAS Metadata Server no no

Note: If you performed an Advanced or Personal installation (using SAS Configuration Wizard), then the servers are configured as follows:

  • SAS Workspace Servers are set up as standard servers (without pooling or load balancing).

  • SAS Stored Process Servers are set up as load-balancing servers that each have three MultiBridge connections. The servers are all configured within the same load-balancing logical server (cluster).

Load Balancing for SAS Stored Process Servers

For SAS Stored Process Servers, you must use load balancing; pooling and standard configurations are not supported. For more information, see Overview of Load Balancing.

Pooling and Load Balancing for SAS Workspace Servers

For SAS Workspace Servers, in addition to the standard configuration, you can also choose to set up either pooling or load balancing, as follows:

  • For COM connections, you can set up pooling to improve the efficiency of connections between clients and servers. For details, see Overview of Pooling.

  • For IOM Bridge connections, you can set up either of these configurations:

    For IOM Bridge connections, you must also set up additional Pooling Security or Load Balancing Security.

To decide whether to use pooling or load balancing, consider the following information:

  Pooling Load Balancing
Type of Performance Improvement Pooling reduces the overhead for each connection and is well-suited to applications that use many quick connections, such as Web applications. Pooling can also distribute the workload across multiple server machines. Load balancing distributes the workload equally across multiple server machines and is well-suited to applications that connect for a long time and submit long jobs, such as desktop applications.
Implementation Location Pooling is implemented within the client code, so your client applications cannot benefit from pooling unless they are coded to use pooling servers. Load balancing is implemented within the spawner, so any client can benefit from load balancing.
Security For pooling, a group login is used to connect to the server. Authorization cannot be performed on the individual user credentials. For load balancing, the user's login is used to connect to the server.
Support for Release 8.2 Clients Yes No