Cloning with Instance Data Replication
Summarize
Summary of Cloning with Instance Data Replication
Cloning with Instance Data Replication (IDR) in ServiceNow involves copying database content and replication configurations from one instance to another. Properly managing which IDR tables are preserved or excluded during cloning is essential to maintain replication integrity and avoid configuration conflicts. There are multiple methods to transfer IDR configurations, including using update sets and clone profiles.
Show less
Methods to Transfer IDR Configuration
- Update Set: Captures configuration changes like selected fields, filters, and data transformations but does not include replicated data. Use the Track in Update Set option to snapshot the IDR configuration and deploy it to another instance.
- Clone Profile: Cloning copies the entire database including data and IDR configuration. You must decide whether to include or exclude the IDR configuration depending on your use case.
IDR Cloning Use Cases
Different cloning strategies determine how IDR configurations are handled:
- Recurring Clone: Regularly clone the source instance to a target without altering the target’s existing IDR configuration. This requires updating preserve and exclude lists in the clone profile accordingly. Use this when target instances have distinct replication setups.
- True Clone: Clone the source instance including its full IDR replication configuration. After cloning, resubscribe consumer instances to the new producer to ensure correct data replication. This is useful when provisioning new instances that inherit existing replication setups.
- Migration Clone: Combines a true clone with preservation of the target instance’s replication configuration. It involves capturing the target’s replication sets via update sets before cloning and re-importing them afterward to maintain both source and target configurations.
Practical Considerations
- Verify replication is properly configured and successful on both source and target instances before and after cloning.
- After a true or migration clone, you must re-create replication sets and resubscribe consumers to ensure data flows correctly.
- When regularly cloning without transferring IDR configuration, update cloning profiles to exclude IDR tables to avoid overwriting target configurations.
Why This Matters
Choosing the appropriate cloning method helps prevent replication conflicts, data integrity issues, and configuration mismatches across ServiceNow instances. It enables smooth environment provisioning, migration, and maintenance while preserving critical replication workflows.
Ensure that certain tables are preserved or excluded to clone your database from one instance to another successfully with Instance Data Replication (IDR).
There are multiple methods for copying an IDR configuration from one instance to another.
- Capture the configuration in an update set
-
An update set captures a group of configuration changes that you can move from one instance to another but doesn’t include data that a producer replicates to a consumer. You can capture a snapshot of an IDR replication configuration, including selected fields, filters, or data transformations using the Track in Update Set option, and then copy it to another instance using an update set. See Deploying a replication configuration from one instance to another in Instance Data Replication.
- Copy the configuration using a clone profile
- Cloning your instance copies everything in the database from one instance to another, including the data and the IDR replication configuration.
Before you clone your instance, you must determine whether to exclude or include your IDR replication configuration.
For details on cloning, see System clone.
IDR cloning use cases
You must preserve and exclude different sets of IDR tables in your cloning profile depending on your cloning use case.
- Recurring clone
- In this use case, you clone your source instance regularly without affecting the existing IDR configuration on the target instance.
For example, you configure IDR to replicate data from instance A to instance B. You determine that you must clone the database from instance A to another instance called instance C. Instance A and instance C both have IDR configured with different replication configurations. When you clone the database from instance A to instance C, you don’t want to clone any of the IDR replication configuration from A to C.
Note:If you regularly clone data from your source instance to your target instance, and find that you need to copy the IDR replication configuration from the source instance to the target instance, use the Track in update set feature to copy the IDR to the target instance.To clone your database from one instance to another without affecting the IDR configuration on the target instance, you must update the preserve and exclude lists in your cloning profile according to the Recurring Clone use case described in KB0965218.
- True clone
- In this use case, you clone your source instance to your target instance and include the complete IDR replication configuration. The target instance inherits everything from the source. After the clone is finished, you must resubscribe all consumer instances to the target
instance.
For example, you decide to provision a new production instance from a non-production instance that already has IDR configured. When you clone the non-production instance, the new production instance inherits everything from the non-production instance. To ensure that data replicates from the production instance and not the non-production instance, you resubscribe all consumer instances to the new production instance.
To clone your database and copy the current IDR configuration to the target instance, you must update the preserve and exclude lists in your cloning profile according to the True Clone use case described in KB0965218.
- Migration clone
- In this use case, you clone your source instance to the target instance, including the complete IDR replication configuration from the source instance, while preserving the target instance’s replication configuration.
The migration clone involves performing a true clone, but with additional steps.
- On the target instance, you create an update set and use the Track in update set feature to upload the existing replication sets on the target instance into the update set.
- Perform a true clone.
- After performing the true clone, you import the update set to the target instances, and you set up replication sets using entry sets to preserve the configuration.
| Use case | Description | Prerequisites | Post requisites |
|---|---|---|---|
| Recurring clone | Clone your source instance to your target instance regularly but exclude your IDR replication configuration. When complete,replication sets on the target instance should not be changed. |
Verify that IDR is configured correctly, and that replication is successful on both the source and target instances. | After performing a recurring clone, you can copy the IDR replication configuration from the source instance to the target instance using the Track in update set feature. |
| True clone | Clone your source instance to your target instance and copy your IDR configuration to the target instance. When complete, entry sets from the source instance should be cloned to the target instance. |
Verify that IDR is configured correctly, and that replication is successful on the source instance. | After performing a true clone, you must perform the following actions on the target instance:
|
| Migration clone | Clone your source instance to your target instance and copy your IDR configuration to the target instance, while preserving the target instance’s replication configuration. When complete, entry sets from the source instance should be cloned to the target instance. |
|
After performing the true clone, you must perform the following actions on the target instance:
|