Distribution Server Features

In this section:

Authorized users should be aware of the following Distribution Server activities and features:


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Distribution Server Startup

During startup, the Distribution Server verifies communication with the Repository, which is an SQL-based repository. During the WebFOCUS Client installation, you can specify an existing SQL data source or choose to have WebFOCUS install and configure the Apache Derby SQL data source. If the Distribution Server cannot communicate with the Repository, it will not start. If the Distribution Server does not start, check the Distribution Server startup trace and log files for error messages. For more information, see Distribution Server Startup Trace Files.

Upon successful initialization, the Distribution Server checks for jobs that need to be recovered as specified by the Recovery and Scanback parameters and jobs that need to run as specified by the NEXTRUNTIME value of each schedule.


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Recovery

Reference:

The purpose of the Recovery parameter in the ReportCaster Server Configuration tool is to recover jobs that were placed in the Distribution Server queue but did not complete schedule execution processing. This could be due to the Distribution Server or Reporting Server being stopped. You can activate the recovery feature by setting Recovery to ON in the ReportCaster Server Configuration tool.

When you create a schedule and the Recovery parameter is set to ON, the RECOVERY field for the schedule is set to N in the BOTSCHED repository table. When the schedule is placed in the run queue, the RECOVERY field is set to Y. This means that if the Distribution Server becomes unavailable while the job is still in the queue, ReportCaster will recover the job when the Distribution Server becomes available even if the Recovery parameter is set to OFF in the ReportCaster Server Configuration tool. After the job is run and all log records have been written, the RECOVERY field is set back to N.

Any job that is running because the Recovery parameter is set to ON runs only once. After the job is placed in the run queue, its NEXTRUNTIME is updated to the next time it should run after the current time. For example, if a job is scheduled to run hourly and the Distribution Server is unavailable for four hours, when the Distribution Server becomes available the job will run only once and will resume running on an hourly basis thereafter.

Note: The Recovery option works independently of the Scanback option. For more information about the Scanback option, see Scanback.



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Reference: How Jobs Are Recovered

Scheduled jobs are recovered as follows:

  1. When you start the Distribution Server, it checks for Recovery ON in the ReportCaster configuration.
  2. If Recovery is set to ON, the Distribution Server reads all records from the BOTSCHED table whose RECOVERY field is set to Y and places them in the run queue, regardless of schedule information and NEXTRUNTIME value.
  3. The Distribution Server begins the process of polling and looking for jobs to run after having queued all the jobs whose RECOVERY field is set to Y.
  4. After the scheduled job is placed on the Distribution Server queue, its NEXTRUNTIME is updated to the next time it should run after the current time.

Note:


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Scanback

In certain instances, the Distribution Server may be unavailable for a period of time. During this time, no scheduled jobs can run. By default, when the Distribution Server becomes available again, it searches for and runs all jobs with a next run time less than the current time and resets the next run time according to the next scheduled run time of the job. If the Distribution Server is unavailable for a long time, you may want to adjust this behavior. Using the Scanback parameter, you can run only those jobs found in a specified time period of the outage, or just reset the next run time of all unexecuted jobs without running them.

There are two Scanback parameters:

The Scanback Interval is active only when the Scanback Type is On. For more information, see Distribution Server Settings.

The Scanback Type parameter can have the following settings:

Note:


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ReportCaster Server Configuration Tool

The ReportCaster Server Configuration tool is an administration tool that allows authorized users the ability to navigate through and change the various settings that define the ReportCaster configuration. For example, the polling interval for the Distribution Server can be changed and access to multiple Reporting Servers can be defined. The configuration settings are accessed from the Configuration tab in the ReportCaster Console. For more information about ReportCaster configuration settings, see ReportCaster Configuration.


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Distribution Server Failover and Workload Distribution

ReportCaster provides the ability to incorporate a backup Distribution Server, and to configure two or more Distribution Servers to share the work of executing scheduled jobs.


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