Change tracking cleanup in Horizon

If you use Horizon with any products using a SQL database (such as Loyalty), then Horizon must have change tracking enabled to ensure the Horizon producers function correctly.

Change tracking consumes storage space, which can impact performance or cause outages. Cleaning up change tracking data provides better control over storage and improves data management efficiency. 

Horizon supports manual change tracking cleanup, which triggers cleanup after confirming that all tracked changes have been successfully sent to Horizon. 

Manual change tracking clean up (which is still triggered automatically) gives you more control over the process. It also reduces the retention period for data, improving how much storage is needed.

Prerequisites

• Horizon version 2.64.0 or above
• Microsoft SQL Server 2016 or above  

Note: If you use an earlier version of Horizon, you can still use automatic change tracking cleanup.  It also remains the default unless manual change tracking cleanup is enabled.

Steps

After upgrading your Central Producer to use manual change tracking, you will need to submit a ticket to Vista support to have manual change tracking cleanup enabled.

1. Download the Horizon producer 2.64 (or above) package from the support site or reach out to your account manager for assistance.

2. Cut the Vista.Service.ReplicationProducer.Central.ServiceHostAdapter.x.x.x.json file from Vista\ServiceFramework\Configuration\UserServiceHostServices\ directory and store it somewhere else.

   Note: This stops the producer and backups your existing configuration.

3. Extract the new package and run the Central Producer installer.
4. Open the new Vista.Service.ReplicationProducer.Central.ServiceHostAdapter.x.x.x.json in the Vista\ServiceFramework\Configuration\UserServiceHostServices\ directory. Update the ServiceName and add CommandLineArguments to the Services section to match the old version of the file.

5. Run producer update scripts against all the databases that are replicating data to Horizon using the HorizonProducer.AddIn.

   Tip: This is in the Horizon producer download package from step 1.

6. Restart the producer.
7. Contact Vista support to log a ticket requesting that manual change tracking cleanup is enabled.

After you finish

The manual change tracking cleanup will run after every replication cycle. If it finds data which has passed the retention period, it will clean it up. (If no data which meets this criteria is found, no cleanup happens.)

The recommended retention period is 1 day. 

Important: Setting the frequency to run more often may cause disruption or server outages, especially for customers with larger Loyalty databases. 

Tip: Your system requirements will be unique depending on factors such as database size and the volume of data changes. If your on-prem Loyalty server encounters issues related to manual change tracking, we recommend you monitor system performance and check the hardware and system requirements your server may need.

See also:

• Horizon overview
• Change tracking in Horizon producers
• Contacting Vista support