Queues

• Add, modify, copy, and delete the records in the queues table;

• Start and stop processing the queue messages for one, many, or all records;

• Start up and shut down the queueing subsystem; and,

• Query the records in the queues table.

An instance of each of the following services exists in the queues table for the PointForce database application:

• {dbs}_email
• {dbs}_generic
• {dbs}_label_print
• {dbs}_remote_data
• {dbs}_report_print
• {dbs}_stage_in
• {dbs}_transfer
• {dbs}_transformation
• {dbs}_xml_file_in
• {dbs}_xml_file_out
• {dbs}_xml_trans_in

Other services may also exist.

Services are grouped by provider type, which identifies whether a given service is using a generic or custom service/implementation and whether it is framework- or application-specific.

The following special actions exist for this table:

• The Start action is used to start processing queue messages for the current or selected records.

• The Stop action is used to stop processing queue messages for the current or selected records.

• The Start All action is used to start processing queue messages for all the search results records.

• The Stop All action is used to stop processing queue messages for all the search results records.

• The Start Up action is used to enable the queueing subsystem (for clusters).

• The Shut Down action is used to disable the queueing subsystem (for clusters).

• The Watch action is used to notify a given user via email when an error occurs while attempting to process a message associated with a given queue. The email message to send and the user to whom it should be sent are predefined.

• The Unwatch action is used to stop monitoring for errors occurring on a given queue.

The following list defines every field available in the queue (md_queue) resource in alphabetical order:

• Being Consumed - this field is not maintainable. An extension column that lists the active messages being consumed at that moment.

• Created By - displays the name of the user who created the record you are viewing or maintaining. May not be overridden.

• Created On - displays the date on which the record that you are creating or maintaining was created. May not be overridden. May also represent the creation date of the records you are attempting to retrieve.

• Database Name - the database that will hold the queue messages.

• Description - an expression column that displays the queue record's description.

• Description Literal Key - the literal key to serve as the queue record's description.

• Documentation - this field is not maintainable. Click the hyperlink associated with a given service for a detailed description of the service provided.

• Errors - this field is not maintainable. Click the hyperlink associated with a given service to open the queue message view for the indicated database.
  • The Is Error field within the queue message will be defaulted to Yes.

• Extra Attributes - a CLOB-type field used to store additional JSON information.

• Is Active - indicates whether or not this service is active. The following options are available: Yes (default) and No.

• Is Group Multi-Thread - indicates whether or not the message group is multi-threaded. The following options are available: No (default) and Yes.
  • A value of No indicates that the message group is not multi-threaded and messages from the same group are processed sequentially.

  • A value of Yes indicates that the message group is multi-threaded and messages from the same group may be processed simultaneously by multiple queue consumers.

• Maximum Number of Threads - the maximum number of threads that can process messages concurrently. The default value is 1.
  • Available only when the Pause Queue on Error flag is set to No.

  • When multiple threads per service are used, it is important to define the number of records per batch. The system counts the number of records available in the queue message table before launching the consumption. Based on this number, it will process the number of threads (i.e. the total number of records divided by the number of records per batch). The number of threads is reevaluated each time a thread has consumed its batch.

• Messages - this field is not maintainable. Click the hyperlink associated with a given service to open the queue message view for the indicated database.

• Modification Counter - this field is not maintainable. The date and time a given record was last modified.

• Modified By - this field is not maintainable. The user or system process that last modified the record.

• Modified On - this field is not maintainable. The date on which the record was last modified.

• Number of Active Threads - this field is not maintainable. An extension column that indicates the number of threads currently processing transactions.

• Number of Idle Threads - this field is not maintainable. An extension column that indicates the number of threads sitting idle, not processing transactions.

• Number of Queue Errors - this field is not maintainable. The number of queue message errors for the given service.

• Number of Queue Messages - this field is not maintainable. The number of queue messages for the given service.

• Pause Queue on Error - the following options are available: Yes and No (default).
  • A value of Yes indicates that the queue consumer will stop processing messages when an error is encountered. It will sleep for a certain time interval and then retrieve a batch of records. The erroneous record will be retried first unless it is either corrected or deleted by an administrator.

  • A value of No indicates that the queue consumer can continue to process messages even if errors are encountered in the messages. In this case, you have the ability to modify the number of threads that can concurrently process messages.

• Provider Type - an expression column that defines whether a service is using a generic or custom service/implementation and whether it is specific to the framework or a given application. The following options are available:
  • Generic Framework
  • Generic Application
  • Generic Application using Framework
  • Custom Framework
  • Custom Application

• Queue Attributes - an expression column that provides details of a queue's attributes.
  • When the field is personalized in the search results of a view, it shows the number of attributes. It is linkable to a view for maintenance of the attributes, and provides a hover preview.

  • When the field is personalized in the Details page, the information is embedded into the page and may be editable by anyone with proper authorization.

• Queue Name - this field is maintainable in creation mode only, when it appears in the key subview. The unique identifier for the queue record.

• Retry Expiry in Seconds - the length of time (in seconds) in which the queue will stop retrying to process a staging record for which there is an execution error.
  • Only applicable when the Retry Policy is set to Interval-Based Retry.

  • Default value set to 3600.

• Retry Interval in Seconds - the interval of time (in seconds) in which the queue will retry to process a staging record for which there is an execution error.
  • Only applicable when the Retry Policy is set to Interval-Based Retry.

  • Default value set to 900.

• Retry Policy - the queue's retry policy. The following options are available:
  • Do Not Retry (default) - indicates that the queue will never retry to process a staging record that has an execution error.

  • Interval-Based Retry - indicates that the queue will retry to process a staging record in error based on the settings of the Retry Interval in Seconds and Retry Expiry in Seconds fields.

• Records Per Batch - the value that represents the number of records that the queue consumer will process per batch.
  • Default value set to 1000.

• Sleep Interval - the value that represents the number of seconds that the queue consumer will sleep when there are no more records in the message queue. When it wakes, it will fetch the next batch of records.
  • It will also sleep when it encounters a record with errors, if the Pause Queue On Error field is set to Yes.

  • If the value is 0, it will sleep until it is notified that a message needs to be consumed. This occurs when a message is created by a timer or through Web services.

  • Default value set to 5.

• Sort Sequence - the order in which a given queue record is to appear in the search results of the application Queue Monitor view.
  • Default value set to 1.

• Table Name - the table that will hold the queue messages.

• Thread Status - the state of a given service. The following options are available:
  • Offline (default)
  • Stopped
  • Running
  • Stopping

For the functionality of each action (i.e. button) available on this view, refer to the About the Actions topic.