Migrating process instances and snapshot data
After a snapshot has been deployed, you can migrate instances and snapshot data from one snapshot to another by using the Process Admin Console or the BPMMigrateInstances command. Snapshot data is also migrated when instances are migrated.
Alternatively, the TWProcessInstance JavaScript object contains methods you can use to migrate process instances individually. Depending on whether you want to use a policy file, you can use the migrateWithContextTo method or the migrateWithPolicyTo method. Do not use the migrateTo method. For more information, see the TWProcessInstance section of JavaScript API in processes and service flows.
Note: To use an API to migrate instances, you must build a custom
service.
Before you begin
To migrate instances, you must be an Business Automation Workflow
administrator or a person with authorization to deploy new snapshots of the process app.
Tip: To ensure migration is successful., follow the development practices and procedures in
Development strategies for migrating instances. Ensure the target snapshot is installed
successfully and avoid using processes in the involved snapshots while the instance migration
process is running.
If orphaned token steps are identified, generate a migration policy file before migrating
instances. For more information, see Managing tokens.
Note: If no orphaned token
steps are identified then the file is not needed.
About this task
After a snapshot is deployed, you can migrate process instances in either of the following ways:
- Use the BPMMigrateInstances wsadmin command - For each source snapshot you want to migrate instances from, run the BPMMigrateInstances wsadmin command. For more information, see BPMMigrateInstances command.
- Use the Migrate Inflight Data option in the Process Admin Console by completing the following procedure.
Note: When you use the Process Admin Console to migrate a
large number of inflight process instances, the server returns very large blocks of instance data to
the client browser, which might cause memory issues that in turn cause the server to crash or hang.
To work around the issue, use the BPMMigrateInstances command or use the
migrate-instances-count setting to migrate smaller blocks of instances. When
using migrate-instances-count, you might have to run the instance migration
multiple times depending on how many instances must be migrated and the value of the
setting.
Procedure
- From the Process Admin Console, select Installed Apps.
- From the list of snapshots, select the one you are migrating data to.
-
Click Migrate Inflight Data.
A source snapshot selection menu opens listing valid snapshots. A snapshot must have active, failed, or suspended instances for it to be listed.
- Select the snapshot you want to migrate data from.
- Optional: Upload a migration policy file.
-
Click Migrate.
When instance migration completes, you see a summary. If instance migration takes a long time, you might see a timeout error instead of the summary. A network timeout won't prevent the instance migration from completing on the server.