Configuring the Business Process Option Servers

 

This section provides instructions for configuring the Business Process Option Servers. This entails editing the variable assignments in the Business Process Option configuration file eLink_BPO.cfg. This section describes this file in detail and provides instructions for modifying its contents to suit your particular configuration. Topics include:

• Overview

• The eLink_BPO.cfg File

• SERVER Sections

• eLink_BPO.cfg Configuration Parameters

Overview

The Business Process Option Servers - also sometimes referred to as the Business Process Option eLink Platform application servers - are responsible for executing and controlling the eLink Platform ATMI services. ATMI services send input and output data to the applications that are connected and controlled by the eLink Platform.

The Business Process Option Server uses the following eLink Agent Server programs to execute and control ATMI services:

• eProcStarter

• eProcRunner

• eTaskAgent.

Essentially, when you configure the Business Process Option Server, you are in effect configuring these eLink Platform Agent Servers. Therefore, the set of these eLink Agent Server programs, along with the Business Process Server itself, are collectively referred to as the Business Process Option Servers. To configure the servers, you must modify the contents of the configuration file eLink_BPO.cfg. The following sections provide a detailed description of this file, and instructions for modifying it to suit your configuration.

The eLink_BPO.cfg File

The Business Process Option Servers are configured and administered through the mechanisms of the following configuration files:

• eLink_BPO.cfg - This is the default Business Process Option configuration file. During initialization, each server reads the configuration file specified in the CLOPT (Command Line Options) line in the UBB configuration file. (Refer to Creating the eLink Platform Configuration Files, for instructions on specifying configuration files.) If no file is specified, the server will fail to boot.

• The eLink Platform UBB configuration file - This is the primary TUXEDO/eLink Platform configuration file. A relationship exists between the eLink_BPO.cfg file and the UBB configuration file, as illustrated in Figure 5-1. Please refer to your TUXEDO and eLink Platform documentation for a description of and instructions on modifying the UBB configuration file.

The eLink_BPO.cfg file is installed in the following location:

<$TUXDIR>/eLink/BusProc/

You should place a working copy of this file in the eLink Platform APPDIR.

Note: Any changes to a configuration file section require that the server(s) using that section be shut down and restarted for the changes to take effect. A listing of the default eLink_BPO.cfg file is provided in Appendix C.

SERVER Sections

The eLink_BPO.cfg file contains at least one section for each server, and may contain a separate section for each instance of the servers. The particular section for a server is read when the server is started, as part of the server initialization process.

Sections are demarked by the following headers:

[SERVER=<servername>]

where <servername> is one of eProcRunner, eProcStarter, or eTaskAgent.

By default, the servers search for a SERVER section equal to the name of the server executable, minus the path information. You can instruct the server to use a section by another name by using the -i <section> option in the CLOPT line.

Note: <section> must consist only of the section name; do not include the entire UBB file section line (for example, use only the <section> portion of the line [SERVER=<section>].

Figure 5-1 illustrates the relationship between the server CLOPT arguments and the server configuration file, for two instances of the eProcRunner server, each using its respective configuration section.

Figure 5-1 Relationship between the UBB and eLink_BPO.cfg Files

eLink_BPO.cfg Configuration Parameters

The relevant section configuration parameters are categorized as follows:

• Business Process Engine Server Login Parameters

• Business Process Option Server Parameters

Business Process Engine Server Login Parameters

The following three parameters are common to each eLink_BPO.cfg file section. These specify the login information to be used by the Business Process Option Server for connections to the appropriate Business Process Engine.

• SERVER - This is the name of the Business Process Engine Server to which to connect. If you used the default installation, this will be the installation machine name.

• USER - This is the Business Process Engine user ID. This must be a user created with the BpoAddUser command during the Business Process Option installation procedure.

• PASSWORD - This is the password assigned to the Business Process Engine user specified for USER, above.

The settings for these parameters are fairly static. These three settings must be present for each server. Specify the Business Process Engine Server machine and login information by replacing the installed defaults with the correct information. These are initially set as follows:

SERVER=<systemname>
USER=<icdba>
PASSWORD=<icdba>

You must modify the assignments for these parameters to the correct settings for your Business Process Engine Server machine; otherwise, attempts by the Business Process Option Server to connect with the Business Process Engine Server will fail.

Business Process Option Server Parameters

The Business Process Option Server parameters are grouped as follows:

• eProcStarter parameter:

  • SERVICE_LIST

• eProcRunner parameters:

  • SERVICE_LIST

  • POLL_INTERVAL

• eTaskAgent parameters:

  • POLL_INTERVAL

  • POLL_COUNT

  • COMPLETE_FAILED_TASK

These are described in the following sections.

eProcStarter Parameters

• SERVICE_LIST - This is a comma-separated list of service names to be advertised. Each of the listed service names must have a corresponding template defined. Each of the names in this list must be unique and meet the TUXEDO/eLink Platform service name requirements. Also, because these are advertised services, each name must be unique when compared to the SERVICE_LIST for the eProcRunner and any other services running in the eLink Platform application.

eProcRunner Parameters

• SERVICE_LIST - This is a comma-separated list of service names to be advertised. Each listed service name must have a corresponding template defined. Each name in this list must be unique and meet the TUXEDO/eLink Platform service name requirements. Also, since these are advertised services, each these names must be unique when compared to the SERVICE_LIST for the eProcStarter and any other services running in the eLink Platform application.

• POLL_INTERVAL - The eProcRunner server waits for a process to complete before returning to the caller. POLL_INTERVAL specifies how often, in tenths of seconds, the server should sleep between process status queries. Longer times result in less CPU use, but potentially more time between completion of the process and notification to the client. Shorter durations result in more CPU use and possibly earlier notification to the client of process completion.

eTaskAgent Parameters

The following parameters control how often the eTaskAgent looks for ready tasks, the number of ready tasks processed in succession, and what to do should processing for a task fail.

Note: The Business Process Engine controls access to tasks and jobs through user logins. Users must belong to at least one pool, which is a group of users. Tasks also must have an assigned pool. Only users in the pool assigned to a particular task may acquire and process the task. The BPO provides the utility BpoAddUser for creating users for the eTaskAgent. BpoAddUser is located in <$TUXDIR>/eLink/BusProc. It creates the specified user and places the user in a pool with the same name as the user (after creating the pool). This is important because the eTaskAgent only processes Tasks with a pool name identical to the USER parameter or the "Owner" pool. This allows tasks to be assigned to certain instances of the eTaskAgent.

• POLL_INTERVAL - This specifies the amount of time the server should wait between queries to the Business Process Engine for ready tasks. The time is specified in tenths of seconds. The longer the delay, the less CPU usage consumed by the eTaskAgent when there are no ready tasks; however, it may take proportionately longer for a ready task to be acquired. Conversely, a shorter interval may allow the server to acquire tasks sooner as they become available, but will consume more processing time when no tasks are ready.

• POLL_COUNT - This is the maximum number of ready tasks that should be processed before forcing the daemon to process another ATMI loop. This ensures that the server responds to TUXEDO/eLink Platform commands such as shutdown, etc. If no ready tasks are available, the server will sleep for the POLL_INTERVAL and process another ATMI loop.

• COMPLETE_FAILED_TASK - This specifies that failed tasks should be marked as completed. If this is set to YES, when a service request fails, the eTaskAgent will mark the task as complete and continue, setting error information on the process level attributes. If this is set to NO, then the eTaskAgent will leave the task as acquired and stop any further processing on this path of execution within the process. Completing failed tasks allows the engine to make decisions regarding error processing, while leaving the task in the acquired state allows for human intervention. The default, should this parameter be unspecified or contain an invalid value, is to complete failed tasks and allow the Business Process Engine to continue processing the job.