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Configuring a Dependent Spawner

Dependent spawners are spawners that assist the main, or master spawner in handling client requests for an IOM server. When you set up and invoke dependent spawners, client requests rotate among master spawners and their dependent spawners on a round-robin basis. This configuration provides more efficient handling of multiple user requests.

Dependent spawners can run on the same host machine as the master spawner, or they can run on other host machines in the network. In addition, a dependent spawner can support more than one master spawner as long as the master spawners all reside in the same domain.

A sample dependent spawner configuration is shown in the diagram below.

Sample dependent spawner configuration

In this example, five dependent spawners are supporting two IOM servers. The dependent spawners are spread among three different host machines.

Defining a Dependent Spawner

To define a dependent spawner, you must create a sasDependentSpawner object using either IT Administrator or a configuration file. The object's attributes are similar to those used for a master spawner. For a complete list of attribute definitions, refer to Attributes for sasDependentSpawner. For the dependent spawner to work correctly, you must follow these guidelines:

For an example of the metadata needed to set up a dependent spawner, refer to the Dependent Spawner configuration file example.

Invoking (Starting) a Dependent Spawner

To start a dependent spawner, use the -dependent invocation option with the spawner command. This option may be abbreviated as -dep.

When a dependent spawner is started, it determines which master spawners it is supporting. It then connects to those spawners' master ports. The connection process notifies the master spawner(s) that the dependent spawner is available to handle client requests.

To connect with the master spawner(s), the dependent spawner performs the following detailed steps:

How Dependent Spawners Work

When a client connects to a master spawner's listen port, the master spawner either processes the request itself or redirects the request to an available dependent spawner. The master spawner uses a round-robin scheduling algorithm to determine which spawner should handle the next request. This process works as follows:

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