Performance issues with the Traffic Prediction feature of IBM Intelligent Operations for Transportation

Technote (troubleshooting)


Problem(Abstract)

The Traffic Prediction feature of IBM® Intelligent Operations for Transportation continuously stores information in database tables to generate the predicted traffic levels of the transportation network. If the LINK_FORECAST and LINK_REPORT database tables grow too large in size, you might experience performance issues.

Symptom

You might experience traffic prediction performance issues arising from the size of some of the Traffic Prediction database tables. The traffic prediction calculations might take time to complete which can result in data not displaying on the map.


Cause

This performance problem can occur when the Traffic Prediction LINK_FORECAST and LINK_REPORT database tables become too large.

Resolving the problem

Regular scheduled pruning of the database using an SQL stored procedure resolves this issue.

Delete all data in the LINK_FORECAST and LINK_REPORT database tables that is older than three months. You can prune the database by using a scheduled SQL stored procedure as outlined in the following steps:

Scheduling the SQL stored procedure

1. Connect to the IBM Intelligent Operations Center data server.
2. Log on as the database administrator.
3. Connect to the TIH_HS database.
4. Run the following command on one line to schedule the stored procedure:
CALL SYSPROC.ADMIN_TASK_ADD ('ADMIN_TASK_NAME',NULL,NULL,NULL,
'SCHEDULE_CRON_EXPRESSION',
'TPTOOL','PURGETRANSPREDFORECASTREPORTDATA',NULL,NULL,NULL);

Where:

  • ADMIN_TASK_NAME is an input value of type VARCHAR that specifies the name for this task. This value cannot be NULL, and cannot exceed 128 bytes.
  • SCHEDULE_CRON_EXPRESSION is an input value of type VARCHAR that specifies the task execution schedule at regular intervals. The task is not scheduled if the value is NULL. The schedule value uses the UNIX cron format, and cannot exceed 1024 bytes.

Removing the schedule

1. Connect to the IBM Intelligent Operations Center data server.
2. Log on as the database administrator.
3. Connect to the TIH_HS database
4. Run the following command to remove the schedule:

CALL SYSPROC.ADMIN_TASK_REMOVE ('ADMIN_TASK_NAME',NULL);

Where ADMIN_TASK_NAME is an input value of type VARCHAR that specifies the name for this task. This value must not be set to NULL, and also must not exceed 128 bytes.

Note:

For Traffic Prediction reporting, there are no restrictions on the from and to dates in the Traffic Prediction accuracy report, but the report can generate information based only on the data present in the system. For example, if the purging scripts are run once a week, the Traffic Prediction feature stores a maximum of three months of data, and the oldest week of data is purged every week for the following 12 weeks. If the duration in the accuracy report is selected to be more than three months, the accuracy report is generated for the existing data in the system only.

Run the purging scripts at off-peak times, as the purging procedure can take a significant time to complete, particularly the first time that you run the procedure.


Related information

UNIX cron format

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Document information


More support for:

IBM Intelligent Transportation
IBM Intelligent Operations for Transportation

Software version:

1.5.0

Operating system(s):

Linux Red Hat - xSeries

Software edition:

All Editions

Reference #:

1625661

Modified date:

2013-03-14

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